Notebookcheck

Dell Inspiron 15 7558 Convertible Review

A fresh take. Dell’s Inspiron 15 7558 continues the manufacturer’s expansion of the Inspiron line into more premium territory, this time with a 2-in-1 convertible design (similar to Lenovo’s smaller Yoga machines). Can it inspire us with its rebalanced priorities?

The Inspiron line of laptops from Dell has long been synonymous with the low-end and entry-level, compromising quality in pursuit of affordability. Along with Lenovo’s G series, HP’s Pavilion series, and plenty of similar offerings from competing manufacturers, it’s the sort of thing you’d find lining the everyday retail shelves in your local big-box stores, but at which enthusiasts quickly turn up their nose.

Then, with the introduction of the Inspiron 7000 series in 2013 (with the Inspiron 15 7537), we began to witness some changes in philosophy. Dell wasn’t ditching the low-end (the Inspiron 3000 series still exists for that purpose), but they were finding ways to muddy the preconceived definitions of what defines an Inspiron. The Inspiron 15 7548 (which we reviewed back in April) was the most extreme entry we’d seen to date; decked out a dual-core i7 CPU, 16 GB of RAM, a 4K touchscreen, and AMD R7 M270 midrange dedicated graphics, this was not your father’s Inspiron.

That might have been overkill in some respects, especially the 4K screen, which produced lower-than-average battery life even with subpar luminosity. And so, the Inspiron 15 7558 takes a different approach: it trades the dedicated graphics and 4K screen for a Yoga-like 2-in-1 convertible design, while simultaneously dialing back a few other specifications to try and find a happy medium. Starting at $550, even the lowest-end configurations sport a 1080p touchscreen, Intel Pentium CPUs, and premium metal casing. Our particular review unit (MSRP $900) packs an Intel Core i5-5200U CPU, 8 GB DDR3 RAM, and integrated Intel HD Graphics 5500. Is this the Inspiron for you?

Dell Inspiron 15 7558 (Inspiron 15 Series)
Graphics adapter
Memory
8192 MB 
, DDR3 1600 MHz
Display
15.6 inch 16:9, 1920 x 1080 pixel, 10-point, BOE0648, glossy: yes
Mainboard
Intel Wildcat Point-LP
Storage
Sandisk X300 SD7SB6S-256G-1012, 256 GB 
Soundcard
Realtek ALC255 @ Intel Broadwell PCH-LP High Definition Audio Controller
Connections
1 USB 2.0, 2 USB 3.0 / 3.1 Gen1, 1 HDMI, 1 Kensington Lock, Audio Connections: 3.5 mm combo, Card Reader: SD, Sensors: gyrometer, accelerometer
Networking
Intel Wireless-N 7265 (b/g/n), Bluetooth 4.0
Size
height x width x depth (in mm): 20 x 381 x 254 ( = 0.79 x 15 x 10 in)
Battery
43 Wh Lithium-Ion, 3-cell
Operating System
Microsoft Windows 10 Home 64 Bit
Camera
Webcam: 720p
Additional features
Speakers: 2.0, bottom-mounted, Keyboard: Chiclet, Keyboard Light: yes, 12 Months Warranty
Weight
2.104 kg ( = 74.22 oz / 4.64 pounds), Power Supply: 248 g ( = 8.75 oz / 0.55 pounds)
Note: The manufacturer may use components from different suppliers including display panels, drives or memory sticks with similar specifications.

 

Case

The first and perhaps most jarring aspect of an Inspiron 7000 is its case design. The 7558 sports a large, sleek brushed aluminum base unit comprising the palm rest and keyboard surround, finished with a conspicuous chamfered edge around the perimeter, and extending down to meet the bottom cover (which is instead heavy-duty plastic with a comfortable rubberized coating). This same plastic material is used for the display lid; Dell calls the color “Foggy Night” (which is a smoke grey color that, by our judgment, is as attractive as it is understated). The large, metal hinge covers and shiny Dell logo round out the exterior.

Overall, the feel of the machine is decidedly premium, even in spite of the usage of less-expensive plastic in a few areas. The weight is manageable for a 15-inch machine at 2.1 kg—identical to that of the Inspiron 15 7548 we previously reviewed. Thanks to its partial metal construction, the base unit is quite sturdy and devoid of flex most everywhere but in the center, which is pretty typical. The display lid, meanwhile, is a bit too twistable for comfort (it’s quite thin for its size)—and moderate pressure on the back produces noticeable distortions on the panel.

The hinges, of course, rotate 360 degrees to accommodate the now-popularized (by Lenovo’s Yoga series) transformations between laptop, tablet, tent, and stand modes. In light of its considerable size, the transformative capabilities are decidedly less appealing, however; our usual complaints regarding the impracticality of oversized convertible notebooks still apply to the Inspiron 7558. The most questionable of all four options is Tablet Mode, where the Inspiron 15’s size and weight greatly diminish its utility—but in all honesty all of the modes apart from the traditional laptop form factor prove rather cumbersome. Despite the unlikelihood of most users regularly taking advantage of Tablet Mode, some design changes necessary to accommodate it also bring along unfortunate side effects—such as the relocation of the power and volume buttons to the front right edge of the machine, where they are easy to accidentally activate (and harder to find when you need them).

The bottom cover of the machine, which is secured by ten Phillips-head screws and a series of clips around the perimeter, isn’t too difficult to remove. Inside, you’ll find plenty of replaceable components, starting with the solid-state drive (or conventional 7mm height mechanical hard drive on lower-priced configurations), battery, CMOS battery, WLAN adapter, and heatsink/fan. What you won’t find, however, is two RAM slots—the Inspiron 15 7558 only offers one, which was populated by a single 8 GB stick of memory in our review unit.

Connectivity

The Inspiron 15 7000 2-in-1 doesn’t provide anything special in the way of connectivity. There is a total of three USB ports, two of which are 3.0, as well as a card reader. That’s not terribly restrictive, though we’d like to see four USB ports on a 15.6-inch machine, and at the very least, it’d be nice if all three of the existing ports supported 3.0 speeds. For video output, the only option is HDMI—which is appropriate for a consumer-grade notebook.

Left: Kensington Lock, charging port, HDMI, USB 3.0 x 2, 3.5 mm combo audio
Left: Kensington Lock, charging port, HDMI, USB 3.0 x 2, 3.5 mm combo audio
Right: Power button, volume rocker, USB 2.0, card reader
Right: Power button, volume rocker, USB 2.0, card reader

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The Intel Dual-Band Wireless-AC 7265
The Intel Dual-Band Wireless-AC 7265

Communication

The Inspiron 15 7558 includes the ubiquitous Intel Dual-Band Wireless-AC 7265 adapter for 802.11ac network communication. The card is installed with a 2x2 antenna configuration, and is capable of connection to both 2.4 GHz and 5 GHz networks. We experienced no problems when using it with our ASUS RT-AC68U router, and signal strength was generally strong and reliable. This adapter also includes Bluetooth 4.0 LE for short-range device connectivity such as audio streaming. There is no Ethernet adapter due to size constraints; unlike some higher-end (professional) models like the ZenBook Pro UX501JW, a separate USB to Ethernet adapter is not included.

Accessories

The Inspiron 15 includes nothing apart from a small (248 g) 45 W AC adapter. The machine uses the smaller Ultrabook-style Dell adapter for charging (in contrast to the classic, larger connector).

Warranty

A 12-month mail-in warranty is included; Dell will pay the shipping, however, the customer must supply the box.

Input Devices

Keyboard

The Inspiron 15’s Chiclet-style keyboard is nearly identical in layout to that of the modern XPS line. Fortunately, the quality also approaches that of those machines. The flat key surfaces are comfortable, and although strokes are short, they are supplemented with a sharp sense of decisive feedback and a low degree of actuation force. This factors out to a short adjustment period for most typists and more effortless typing for extended periods. Key strokes are moderately quiet, though louder than competing models thanks to the sharp feedback.

Of particular note is the lack of a number pad as is frequently included on 15.6-inch models. Finally, the keyboard is illuminated, with two levels of illumination in addition to off. The illumination is relatively consistent across the keys.

Touchpad

The Inspiron 15’s touchpad is a large clickpad supporting multitouch for gesture input (which worked well in our testing). Only the bottom of the pad depresses, and the actuation force is quite low, though the stroke is sufficient and the feedback is good. We do prefer the tighter construction and slightly higher actuation force of the XPS design, but the Inspiron 15’s is not problematic as are many clickpads. Dragging and dropping was not overly challenging, and the textured surface makes gliding across the pad comfortable.

Touchscreen

Finally, of course, the Inspiron 15 7558 features a capacitive touchscreen supporting 10-point multitouch input. The screen reacts to input without any significant delay and is accurate even in the corners.

Display

Unlike the Inspiron 15 7548, the 7558 does not offer a 4K panel as an option. In fact, only one 15.6-inch screen option is available: a glossy 1080p (1920x1080) panel. That’s a PPI of 141, which is nothing special by today’s standards, but fine for practical purposes. The manufacturer doesn’t advertise it, but the panel thankfully also uses IPS technology, which is most appropriate for any convertible machine. Subjectively, the screen appears rather ordinary, with good contrast, but somewhat muted colors and middling brightness. The picture temperature also appears quite warm.

214.7
cd/m²
209.8
cd/m²
213.7
cd/m²
201.9
cd/m²
208.6
cd/m²
195.4
cd/m²
197.2
cd/m²
202.3
cd/m²
195.2
cd/m²
Distribution of brightness
X-Rite i1Basic Pro 2
Maximum: 214.7 cd/m² Average: 204.3 cd/m²
Brightness Distribution: 91 %
Center on Battery: 208.6 cd/m²
Contrast: 841:1 (Black: 0.248 cd/m²)
ΔE Color 5.62 | 0.4-29.43 Ø6.3
ΔE Greyscale 4.44 | 0.64-98 Ø6.5
63.1% sRGB (Argyll 3D) 40.2% AdobeRGB 1998 (Argyll 3D)
Gamma: 2.06

Indeed, our impressions are supported by our measurements, which reveal a disappointing average brightness of just 204.3 cd/m². At least the contrast ratio of 841:1 is good, salvaged by a low black value of just 0.248 cd/m².

Our color space measurements reveal just a 63% coverage of the sRGB spectrum, which explains why colors subjectively appear rather dull on the screen. Of course, AdobeRGB is even lower at just 40%. These values aren’t likely to bother the average user too much, but it goes without saying that users considering a purchase of the Inspiron for any sort of heavy-duty graphics design or photo editing may want to look elsewhere.

vs. sRGB
vs. sRGB
vs. AdobeRGB 1998
vs. AdobeRGB 1998
vs. Inspiron 15-7537
vs. Inspiron 15-7537
vs. Zenbook Pro UX501JW
vs. Zenbook Pro UX501JW
Dell Inspiron 15 7558
HD Graphics 5500, 5200U, Sandisk X300 SD7SB6S-256G-1012
Dell Inspiron 15-7548
Radeon R7 M270, 5500U, Liteon IT LCS-256L9S-11
Dell Inspiron 15-7537
GeForce GT 750M, 4500U, Samsung SSD SM841 256GB MZ7PD256HAFV
Asus Zenbook Pro UX501JW-FI218H
GeForce GTX 960M, 4720HQ, SanDisk SD7SN3Q128G1002
Toshiba Satellite L50-B-1TD
Radeon R7 M260, 4510U, Toshiba HG6 THNSNJ256GMCU
Response Times
Response Time Grey 50% / Grey 80% *
43.2 (18, 25.2)
Response Time Black / White *
27.2 (7.6, 19.6)
PWM Frequency
Screen
-50%
7%
-21%
-10%
Brightness middle
208.6
214
3%
271
30%
302
45%
299
43%
Brightness
204
204
0%
267
31%
307
50%
299
47%
Brightness Distribution
91
77
-15%
84
-8%
87
-4%
77
-15%
Black Level *
0.248
0.76
-206%
0.25
-1%
0.79
-219%
0.54
-118%
Contrast
841
282
-66%
1084
29%
382
-55%
554
-34%
Colorchecker DeltaE2000 *
5.62
5.83
-4%
6.22
-11%
5.4
4%
5.96
-6%
Greyscale DeltaE2000 *
4.44
7.17
-61%
6.72
-51%
5.99
-35%
5.52
-24%
Gamma
2.06 107%
1.94 113%
2.47 89%
2.32 95%
2.29 96%
CCT
5889 110%
5617 116%
5736 113%
6670 97%
5831 111%
Color Space (Percent of AdobeRGB 1998)
40.2
55
37%
45
12%
51
27%
Color Space (Percent of sRGB)
63.1
71
13%
Total Average (Program / Settings)
-50% / -50%
7% / 7%
-21% / -21%
-10% / -10%

* ... smaller is better

With an out-of-box pre-calibration ColorChecker deltaE2000 average of 5.62 (ideal: 0), the Dell Inspiron 7558 isn’t too far off the mark on most colors to begin with. The exception to this is shades of blue, where the panel is afflicted by values as high as 12. Post-calibration, the deltaE average dropped to 3.58, which is quite good. Pre-calibrated grayscale averages weren’t quite as nice: we measured a dE grayscale average of 4.44 (ideal: 0), Total Gamma of 2.06 (ideal: 2.2), and a warmer-than-usual CCT Average of 5889 (ideal: 6500K). Post-calibration, these values improved to 0.72, 2.22, and 6516, respectively, which are all three very close to ideal.

Color analysis, pre-calibration
Color analysis, pre-calibration
Saturation analysis, pre-calibration
Saturation analysis, pre-calibration
Grayscale analysis, pre-calibration
Grayscale analysis, pre-calibration
Color analysis, post-calibration
Color analysis, post-calibration
Saturation analysis, post-calibration
Saturation analysis, post-calibration
Grayscale analysis, post-calibration
Grayscale analysis, post-calibration

Viewing angles are excellent apart from the distracting reflections imposed by the glossy panel finish. This same finish is also the reason, in conjunction with the weak brightness, why outdoor use is nearly impossible except in shaded environments.

In the sun
In the sun
In the shade
In the shade

Performance

The Inspiron 15 7558 can be equipped with Intel CPUs ranging from a Pentium 3825U (on the lowest-end $550 configuration) all the way to a Core i7-5500U (on one of the multiple $900 options). Memory configurations are either 4 GB or 8 GB of DDR3L 1600 MHz, but all options are single-channel, as there is only one memory slot available (unlike the Inspiron 15 7548).

Our review unit was one of the most expensive configurations, featuring 8 GB of DDR3L RAM and an SSD (detailed later), even though the CPU curiously is not the highest-end option; we received a Core i5-5200U. The machine feels snappy throughout all operations regardless, rarely hiccupping in any situation and generally only buckling when graphics-intensive tasks are at hand.

We tested performance while running unplugged by comparing 3DMark 11 scores against those obtained while charging. The results were nearly identical, with a score of 1106 falling just barely below our original result of 1174. LatencyMon, on the other hand, reported some questionable DPC latencies after running for several minutes (see our screenshot)—but these were few and far between in the system’s defense.

Processor

CPU options in the Inspiron 15 7558 range from Intel Pentium to Intel Core i7 (dual-core) models. All CPUs are ULV offerings based on the Broadwell architecture (14 nm manufacturing process). Our particular review configuration includes an Intel Core i5-5200U, which is a dual-core CPU with a clock rate ranging between 2.2 – 2. 7 GHz (2 cores: 2.5 GHz) and a TDP of 15 W.

In terms of performance, the Core i5-5200U most closely parallels the Haswell-based Core i5-4300U, which is more than capable of handling just about any task the average user can throw its way. The Inspiron 15 7558 handles its equipment respectably, churning out performances at full Turbo Boost frequencies while rarely missing a beat. As compared to other similarly-equipped machines, such as the HP 15-r220ng and the HP Envy 15-u200ng x360, its results are right on the money: all three notebooks scored an identical 259 in Cinebench R15 xCPU 64-bit. Meanwhile, the Inspiron 15 7548, with its slightly nimbler Core i7-5500U, posts a 294 by comparison.

Cinebench R10 Shading 64Bit
6154 Points
Cinebench R10 Rendering Multiple CPUs 64Bit
11016 Points
Cinebench R10 Rendering Single CPUs 64Bit
5409 Points
Cinebench R10 Shading 32Bit
6264
Cinebench R10 Rendering Multiple CPUs 32Bit
6850
Cinebench R10 Rendering Single 32Bit
4159
Cinebench R11.5 OpenGL 64Bit
18.62 fps
Cinebench R11.5 CPU Multi 64Bit
2.75 Points
Cinebench R11.5 CPU Single 64Bit
1.08 Points
Cinebench R15 Ref. Match 64Bit
98 %
Cinebench R15 OpenGL 64Bit
25.09 fps
Cinebench R15 CPU Multi 64Bit
259 Points
Cinebench R15 CPU Single 64Bit
109 Points
Help
Cinebench R15
CPU Single 64Bit (sort by value)
Dell Inspiron 15 7558
109 Points ∼53%
Dell Inspiron 15-7548
121 Points ∼58% +11%
Dell Inspiron 15-7537
105 Points ∼51% -4%
Asus Zenbook Pro UX501JW-FI218H
131 Points ∼63% +20%
Toshiba Satellite L50-B-1TD
119 Points ∼57% +9%
CPU Multi 64Bit (sort by value)
Dell Inspiron 15 7558
259 Points ∼8%
Dell Inspiron 15-7548
294 Points ∼9% +14%
Dell Inspiron 15-7537
195 Points ∼6% -25%
Asus Zenbook Pro UX501JW-FI218H
606 Points ∼19% +134%
Toshiba Satellite L50-B-1TD
272 Points ∼9% +5%
Ref. Match 64Bit (sort by value)
Dell Inspiron 15 7558
98 % ∼98%
Dell Inspiron 15-7548
98 % ∼98% 0%
Dell Inspiron 15-7537
99.6 % ∼100% +2%
Asus Zenbook Pro UX501JW-FI218H
99.6 % ∼100% +2%
Toshiba Satellite L50-B-1TD
98 % ∼98% 0%
OpenGL 64Bit (sort by value)
Dell Inspiron 15 7558
25.09 fps ∼13%
Dell Inspiron 15-7548
37.01 fps ∼19% +48%
Dell Inspiron 15-7537
59.73 fps ∼30% +138%
Asus Zenbook Pro UX501JW-FI218H
94.73 fps ∼48% +278%
Toshiba Satellite L50-B-1TD
33.81 fps ∼17% +35%
Cinebench R10
Rendering Single CPUs 64Bit (sort by value)
Dell Inspiron 15 7558
5409 Points ∼56%
Dell Inspiron 15-7537
5284 Points ∼55% -2%
Rendering Multiple CPUs 64Bit (sort by value)
Dell Inspiron 15 7558
11016 Points ∼14%
Dell Inspiron 15-7537
8643 Points ∼11% -22%
Shading 64Bit (sort by value)
Dell Inspiron 15 7558
6154 Points ∼29%
Dell Inspiron 15-7537
6726 Points ∼31% +9%
Rendering Single 32Bit (sort by value)
Dell Inspiron 15 7558
4159 Points ∼38%
Dell Inspiron 15-7548
4634 Points ∼43% +11%
Dell Inspiron 15-7537
3923 Points ∼36% -6%
Asus Zenbook Pro UX501JW-FI218H
5114 Points ∼47% +23%
Toshiba Satellite L50-B-1TD
4527 Points ∼42% +9%
Rendering Multiple CPUs 32Bit (sort by value)
Dell Inspiron 15 7558
6850 Points ∼14%
Dell Inspiron 15-7548
9950 Points ∼20% +45%
Dell Inspiron 15-7537
6843 Points ∼14% 0%
Asus Zenbook Pro UX501JW-FI218H
18678 Points ∼38% +173%
Toshiba Satellite L50-B-1TD
9148 Points ∼18% +34%
Shading 32Bit (sort by value)
Dell Inspiron 15 7558
6264 Points ∼40%
Dell Inspiron 15-7548
6269 Points ∼40% 0%
Dell Inspiron 15-7537
6699 Points ∼42% +7%
Asus Zenbook Pro UX501JW-FI218H
6740 Points ∼43% +8%
Toshiba Satellite L50-B-1TD
6098 Points ∼39% -3%
Cinebench R11.5
CPU Single 64Bit (sort by value)
Dell Inspiron 15 7558
1.08 Points ∼46%
Dell Inspiron 15-7548
1.42 Points ∼61% +31%
Dell Inspiron 15-7537
1.09 Points ∼47% +1%
Asus Zenbook Pro UX501JW-FI218H
1.52 Points ∼65% +41%
Toshiba Satellite L50-B-1TD
1.35 Points ∼58% +25%
CPU Multi 64Bit (sort by value)
Dell Inspiron 15 7558
2.75 Points ∼10%
Dell Inspiron 15-7548
3.21 Points ∼12% +17%
Dell Inspiron 15-7537
2.12 Points ∼8% -23%
Asus Zenbook Pro UX501JW-FI218H
6.76 Points ∼25% +146%
Toshiba Satellite L50-B-1TD
2.92 Points ∼11% +6%
OpenGL 64Bit (sort by value)
Dell Inspiron 15 7558
18.62 fps ∼14%
Dell Inspiron 15-7548
34.29 fps ∼26% +84%
Dell Inspiron 15-7537
43.95 fps ∼33% +136%
Asus Zenbook Pro UX501JW-FI218H
60.45 fps ∼45% +225%
Toshiba Satellite L50-B-1TD
35.17 fps ∼26% +89%

Legend

 
Dell Inspiron 15 7558 Intel Core i5-5200U, Intel HD Graphics 5500, Sandisk X300 SD7SB6S-256G-1012
 
Dell Inspiron 15-7548 Intel Core i7-5500U, AMD Radeon R7 M270, Liteon IT LCS-256L9S-11
 
Dell Inspiron 15-7537 Intel Core i7-4500U, NVIDIA GeForce GT 750M, Samsung SSD SM841 256GB MZ7PD256HAFV
 
Asus Zenbook Pro UX501JW-FI218H Intel Core i7-4720HQ, NVIDIA GeForce GTX 960M, SanDisk SD7SN3Q128G1002
 
Toshiba Satellite L50-B-1TD Intel Core i7-4510U, AMD Radeon R7 M260, Toshiba HG6 THNSNJ256GMCU

System Performance

The Inspiron 15 7558 we received for review zips through typical office tasks and lightweight web browsing without any hesitation—though most of this is surely attributable to the solid-state drive in our configuration, which is not present in most others. We’ll explore that in greater detail in our next section, but for now, suffice it to say that a PCMark 7 score of 4680 helps to corroborate our observations. Once again, of course, the Inspiron 15 7548 bests it with a score of 5417 (nearly 16% better), but this is probably again primarily a factor of storage speed, where the 7548 holds a small but significant lead over the 7558. We find opposite results in PCMark 8 Work Accelerated v2 (7558: 3876 vs. 7548: 3413, a difference of 13.5%), but this idiosyncrasy is likely more a factor of the lower screen resolution of the 7558.

PCMark 7 Score
4680 points
PCMark 8 Home Score Accelerated v2
2848 points
PCMark 8 Creative Score Accelerated v2
3359 points
PCMark 8 Work Score Accelerated v2
3876 points
Help
PCMark 8
Work Score Accelerated v2 (sort by value)
Dell Inspiron 15 7558
3876 Points ∼59%
Dell Inspiron 15-7548
3413 Points ∼52% -12%
Toshiba Satellite L50-B-1TD
4670 Points ∼72% +20%
Creative Score Accelerated v2 (sort by value)
Dell Inspiron 15 7558
3359 Points ∼35%
Dell Inspiron 15-7548
3826 Points ∼40% +14%
Toshiba Satellite L50-B-1TD
3879 Points ∼41% +15%
Home Score Accelerated v2 (sort by value)
Dell Inspiron 15 7558
2848 Points ∼47%
Dell Inspiron 15-7548
2805 Points ∼46% -2%
Toshiba Satellite L50-B-1TD
3291 Points ∼54% +16%
PCMark 7 - Score (sort by value)
Dell Inspiron 15 7558
4680 Points ∼54%
Dell Inspiron 15-7548
5417 Points ∼63% +16%
Asus Zenbook Pro UX501JW-FI218H
5616 Points ∼65% +20%

Legend

 
Dell Inspiron 15 7558 Intel Core i5-5200U, Intel HD Graphics 5500, Sandisk X300 SD7SB6S-256G-1012
 
Dell Inspiron 15-7548 Intel Core i7-5500U, AMD Radeon R7 M270, Liteon IT LCS-256L9S-11
 
Asus Zenbook Pro UX501JW-FI218H Intel Core i7-4720HQ, NVIDIA GeForce GTX 960M, SanDisk SD7SN3Q128G1002
 
Toshiba Satellite L50-B-1TD Intel Core i7-4510U, AMD Radeon R7 M260, Toshiba HG6 THNSNJ256GMCU

Storage Devices

Most Inspiron 15 7558 configurations include a conventional mechanical hard drive of either 500 GB or 1 TB in size; however, if the cost is not an issue, upgrading to a solid-state drive (even aftermarket, as the replacement is relatively simple) will make a massive difference in overall system responsiveness. Our review system shipped with an SSD already installed—specifically, a SanDisk X300 2.5-inch SATA drive with a 256 GB capacity. The drive is quite fast as judged by our benchmarks: a score of 822 (hindered mostly by a Write score of 232 thanks to a slower-than-average 4K-64 speed of just 134.7 MB/s) and sequential read speeds of well over 400 MB/s mean that the machine is hardly ever waiting on storage access operations. CrystalDiskMark 3.0.1’s results agree.

Sandisk X300 SD7SB6S-256G-1012
Transfer Rate Minimum: 331.5 MB/s
Transfer Rate Maximum: 372.5 MB/s
Transfer Rate Average: 367.8 MB/s
Access Time: 0.1 ms
Burst Rate: 72.3 MB/s
CPU Usage: 1.4 %

GPU Performance

Unlike the Inspiron 15 7548, the 7558 ditches the option for dedicated graphics on higher-end configurations and instead sticks with integrated Intel HD Graphics 5500 across the board. Clock rates vary in accordance with the CPU it’s paired with, but for the most part, the performance is pretty similar between configurations, and it’s nothing great. Part of the reason is that the RAM provisions (whether 4 GB or 8 GB) are single-channel only; dual-channel RAM configurations can sometimes significantly increase the performance of Intel integrated graphics.

The result is a 3DMark 11 score of just 1174 and a 3DMark 2013 Cloud Gate score of 4561, which are below the averages for the Intel HD Graphics 5500 adapter, again most likely due to the single-channel RAM. This is compared with a 3DMark 11 score of 2026 on the 7548 (though curiously our 3DMark 2013 benchmarks for the 7548 appear to show Intel HD Graphics results as though AMD’s Enduro switching failed to make the proper choice). The first-gen Inspiron 7000 series, meanwhile, which launched in 2013 (the Inspiron 15 7537) performs even better than the 7548 in all benchmarks (3DMark 11: 2632; 3DMark Cloud Gate: 5766) thanks to its superior Nvidia GT 750M adapter. Boiling it all down, the Inspiron 15 7558 clearly is no longer a candidate for any sort of 3D gaming.

3DMark 11 Performance
1174 points
3DMark Ice Storm Standard Score
42527 points
3DMark Cloud Gate Standard Score
4561 points
3DMark Fire Strike Score
618 points
Help
3DMark 11
1280x720 Performance Combined (sort by value)
Dell Inspiron 15 7558
951 Points ∼5%
Dell Inspiron 15-7548
1955 Points ∼11% +106%
Dell Inspiron 15-7537
2314 Points ∼13% +143%
Asus Zenbook Pro UX501JW-FI218H
5221 Points ∼30% +449%
Toshiba Satellite L50-B-1TD
1470 Points ∼8% +55%
1280x720 Performance Physics (sort by value)
Dell Inspiron 15 7558
3214 Points ∼18%
Dell Inspiron 15-7548
4255 Points ∼24% +32%
Dell Inspiron 15-7537
2799 Points ∼16% -13%
Asus Zenbook Pro UX501JW-FI218H
7092 Points ∼40% +121%
Toshiba Satellite L50-B-1TD
3840 Points ∼22% +19%
1280x720 Performance GPU (sort by value)
Dell Inspiron 15 7558
1072 Points ∼2%
Dell Inspiron 15-7548
1842 Points ∼4% +72%
Dell Inspiron 15-7537
2650 Points ∼5% +147%
Asus Zenbook Pro UX501JW-FI218H
5135 Points ∼10% +379%
Toshiba Satellite L50-B-1TD
1796 Points ∼4% +68%
1280x720 Performance (sort by value)
Dell Inspiron 15 7558
1174 Points ∼4%
Dell Inspiron 15-7548
2026 Points ∼7% +73%
Dell Inspiron 15-7537
2632 Points ∼9% +124%
Asus Zenbook Pro UX501JW-FI218H
5365 Points ∼18% +357%
Toshiba Satellite L50-B-1TD
1905 Points ∼6% +62%
3DMark
Fire Strike Extreme Combined (sort by value)
Dell Inspiron 15-7537
416 Points ∼5%
Fire Strike Extreme Physics (sort by value)
Dell Inspiron 15-7537
2807 Points ∼10%
Fire Strike Extreme Graphics (sort by value)
Dell Inspiron 15-7537
882 Points ∼4%
Fire Strike Extreme Score (sort by value)
Dell Inspiron 15-7537
874 Points ∼5%
1920x1080 Fire Strike Combined (sort by value)
Dell Inspiron 15 7558
235 Points ∼2%
Dell Inspiron 15-7537
797 Points ∼7% +239%
Asus Zenbook Pro UX501JW-FI218H
1693 Points ∼14% +620%
Toshiba Satellite L50-B-1TD
327 Points ∼3% +39%
1920x1080 Fire Strike Physics (sort by value)
Dell Inspiron 15 7558
4110 Points ∼15%
Dell Inspiron 15-7548
4840 Points ∼18% +18%
Dell Inspiron 15-7537
3394 Points ∼13% -17%
Asus Zenbook Pro UX501JW-FI218H
7260 Points ∼27% +77%
Toshiba Satellite L50-B-1TD
4155 Points ∼15% +1%
1920x1080 Fire Strike Graphics (sort by value)
Dell Inspiron 15 7558
650 Points ∼2%
Dell Inspiron 15-7548
1184 Points ∼3% +82%
Dell Inspiron 15-7537
1877 Points ∼5% +189%
Asus Zenbook Pro UX501JW-FI218H
4197 Points ∼10% +546%
Toshiba Satellite L50-B-1TD
1050 Points ∼3% +62%
1920x1080 Fire Strike Score (sort by value)
Dell Inspiron 15 7558
618 Points ∼2%
Dell Inspiron 15-7548
1129 Points ∼4% +83%
Dell Inspiron 15-7537
1756 Points ∼7% +184%
Asus Zenbook Pro UX501JW-FI218H
3869 Points ∼14% +526%
Toshiba Satellite L50-B-1TD
946 Points ∼4% +53%
1280x720 Sky Diver Physics (sort by value)
Dell Inspiron 15-7548
4234 Points ∼15%
Toshiba Satellite L50-B-1TD
4474 Points ∼16%
1280x720 Sky Diver Graphics (sort by value)
Dell Inspiron 15-7548
3146 Points ∼3%
Toshiba Satellite L50-B-1TD
3593 Points ∼3%
1280x720 Sky Diver Score (sort by value)
Dell Inspiron 15-7548
3316 Points ∼6%
Toshiba Satellite L50-B-1TD
3740 Points ∼7%
1280x720 Cloud Gate Standard Physics (sort by value)
Dell Inspiron 15 7558
2864 Points ∼7%
Dell Inspiron 15-7548
3375 Points ∼9% +18%
Dell Inspiron 15-7537
2001 Points ∼5% -30%
Asus Zenbook Pro UX501JW-FI218H
4789 Points ∼12% +67%
Toshiba Satellite L50-B-1TD
2898 Points ∼7% +1%
1280x720 Cloud Gate Standard Graphics (sort by value)
Dell Inspiron 15 7558
5492 Points ∼3%
Dell Inspiron 15-7548
4766 Points ∼3% -13%
Dell Inspiron 15-7537
12473 Points ∼7% +127%
Asus Zenbook Pro UX501JW-FI218H
21686 Points ∼12% +295%
Toshiba Satellite L50-B-1TD
5002 Points ∼3% -9%
1280x720 Cloud Gate Standard Score (sort by value)
Dell Inspiron 15 7558
4561 Points ∼9%
Dell Inspiron 15-7548
4366 Points ∼9% -4%
Dell Inspiron 15-7537
5766 Points ∼12% +26%
Asus Zenbook Pro UX501JW-FI218H
12155 Points ∼25% +166%
Toshiba Satellite L50-B-1TD
4307 Points ∼9% -6%
1280x720 Ice Storm Standard Physics (sort by value)
Dell Inspiron 15 7558
31813 Points ∼20%
Dell Inspiron 15-7548
14154 Points ∼9% -56%
Dell Inspiron 15-7537
21459 Points ∼14% -33%
Asus Zenbook Pro UX501JW-FI218H
33055 Points ∼21% +4%
Toshiba Satellite L50-B-1TD
34894 Points ∼22% +10%
1280x720 Ice Storm Standard Graphics (sort by value)
Dell Inspiron 15 7558
47055 Points ∼6%
Dell Inspiron 15-7548
14683 Points ∼2% -69%
Dell Inspiron 15-7537
44857 Points ∼6% -5%
Asus Zenbook Pro UX501JW-FI218H
28321 Points ∼4% -40%
Toshiba Satellite L50-B-1TD
30031 Points ∼4% -36%
1280x720 Ice Storm Standard Score (sort by value)
Dell Inspiron 15 7558
42527 Points ∼4%
Dell Inspiron 15-7548
14562 Points ∼1% -66%
Dell Inspiron 15-7537
36107 Points ∼3% -15%
Asus Zenbook Pro UX501JW-FI218H
29251 Points ∼3% -31%
Toshiba Satellite L50-B-1TD
30990 Points ∼3% -27%
3DMark 06 - 1280x1024 Standard AA:0x AF:0x (sort by value)
Dell Inspiron 15-7548
10024 Points ∼24%
Dell Inspiron 15-7537
11398 Points ∼27%

Legend

 
Dell Inspiron 15 7558 Intel Core i5-5200U, Intel HD Graphics 5500, Sandisk X300 SD7SB6S-256G-1012
 
Dell Inspiron 15-7548 Intel Core i7-5500U, AMD Radeon R7 M270, Liteon IT LCS-256L9S-11
 
Dell Inspiron 15-7537 Intel Core i7-4500U, NVIDIA GeForce GT 750M, Samsung SSD SM841 256GB MZ7PD256HAFV
 
Asus Zenbook Pro UX501JW-FI218H Intel Core i7-4720HQ, NVIDIA GeForce GTX 960M, SanDisk SD7SN3Q128G1002
 
Toshiba Satellite L50-B-1TD Intel Core i7-4510U, AMD Radeon R7 M260, Toshiba HG6 THNSNJ256GMCU
low med. high ultra
BioShock Infinite (2013) 29.4218.5314.994.7fps

Emissions

System Noise

The Inspiron 15 7558 never really reached any sort of bothersome noise levels throughout our testing; in fact, most times, it was barely audible at all, emitting just 28.2 dB(A) noise while idle. Under these conditions, the system fan is turned off. Even while under load, the maximum noise level we recorded was just 33.1 dB(A)—hardly troubling.

However, these results do not tell the full story in this case. Unfortunately, the Inspiron 15 7558 is afflicted by the infamous “coil whine” phenomenon that once plagued the older Dell XPS 15 models (as well as previous the Inspiron 15), and it is audible (albeit not to a terrible extent) under all circumstances where the notebook is awake and idling. The noise is a high-pitched screeching/whining noise which emanates from the left side of the keyboard; it is independent of both the keyboard backlight setting and power status. We first noticed it when operating the machine in a relatively quiet room and it was quickly bothersome to our admittedly quite sensitive ears. If the XPS 15’s problems are any indication, it is unlikely that this problem can be solved without Dell issuing a mainboard revision/replacement down the road. However, also like the XPS, it’s not likely to bother all users.

Noise Level

Idle
28.1 / 28.2 / 28.3 dB(A)
Load
33.1 / 33.1 dB(A)
  red to green bar
 
 
30 dB
silent
40 dB(A)
audible
50 dB(A)
loud
 
min: dark, med: mid, max: light   BK Precision 732A (15 cm distance)
The system fan is very quiet...
The system fan is very quiet...
...however, temperatures can become uncomfortable.
...however, temperatures can become uncomfortable.

Temperature

The Inspiron 15 7558 is mostly tolerable in terms of heat emissions, with overall averages of 30/30.6 °C (top/bottom) while idle and 33.3/36.4 °C under load. But there is one particular hot spot in the upper-right quadrant of the bottom of the machine (and, to a lesser extent, adjacent quadrants). This particular spot reached 50.4 °C, which is certainly uncomfortable for lap-borne use and would seemingly serve as a premonition to thermal throttling (we’ll see in our next section).

Max. Load
 38.6 °C
101 F
39.2 °C
103 F
31.2 °C
88 F
 
 36.8 °C
98 F
35.2 °C
95 F
29.6 °C
85 F
 
 31.6 °C
89 F
29.8 °C
86 F
28 °C
82 F
 
Maximum: 39.2 °C = 103 F
Average: 33.3 °C = 92 F
30.8 °C
87 F
43.6 °C
110 F
50.4 °C
123 F
31 °C
88 F
36.2 °C
97 F
48 °C
118 F
28.4 °C
83 F
28.8 °C
84 F
30.6 °C
87 F
Maximum: 50.4 °C = 123 F
Average: 36.4 °C = 98 F
Power Supply (max.)  42.2 °C = 108 F | Room Temperature 24.3 °C = 76 F | Fluke 62 Mini IR Thermometer
Dell Inspiron 15 7558
HD Graphics 5500, 5200U, Sandisk X300 SD7SB6S-256G-1012
Dell Inspiron 15-7548
Radeon R7 M270, 5500U, Liteon IT LCS-256L9S-11
Dell Inspiron 15-7537
GeForce GT 750M, 4500U, Samsung SSD SM841 256GB MZ7PD256HAFV
Asus Zenbook Pro UX501JW-FI218H
GeForce GTX 960M, 4720HQ, SanDisk SD7SN3Q128G1002
Toshiba Satellite L50-B-1TD
Radeon R7 M260, 4510U, Toshiba HG6 THNSNJ256GMCU
Heat
1%
6%
-3%
0%
Maximum Upper Side *
39.2
43.5
-11%
51.1
-30%
46.2
-18%
45.4
-16%
Maximum Bottom *
50.4
54
-7%
44.6
12%
52.5
-4%
57.7
-14%
Idle Upper Side *
31.8
29.8
6%
26.3
17%
32
-1%
26.9
15%
Idle Bottom *
36.4
31
15%
27
26%
32.7
10%
30.4
16%

* ... smaller is better

Stress Test

Even in spite of the aforementioned thermal concerns, the Inspiron 15 still manages to maintain full CPU Turbo clock rates (at 2.5 GHz) stably when the CPU is stressed to 100% using Prime95. Maximum temperatures of 80 °C are encountered briefly before the machine kicks the fan into gear and lowers it back down to around 72 °C. Next, GPU stress (using FurMark) sees the eventual hovering of frequencies around the 750 to 800 MHz mark, but yet again, temperatures are not a prime concern.

Finally, with both GPU and CPU stress at 100%, CPU clock rates stay glued to the 1.5 GHz, while the GPU shuffles between 700 and 750 MHz, occasionally touching 800 MHz. Temperatures remain fairly consistent at the 65 °C mark. The machines does not appear to suffer real-world consequences here; a subsequent run of 3DMark 11 produced a result of 1128, very close to that of our original benchmark.

Full CPU stress
Full CPU stress
Full GPU stress
Full GPU stress
Combined CPU + GPU stress
Combined CPU + GPU stress

Speakers

The Inspiron 15’s speakers are nothing special. Unlike the premium drivers on Dell’s Latitude 7000 series notebooks, the speakers on this Inspiron 7000 series lack mids and lows even under the most appropriate post-processing settings available. The software in use to accommodate such processing is the same Dell Audio package (powered by Realtek) that we’ve seen in the past; however, here, the hardware just isn’t there to support any substantive results. Volume is at least reasonably good, though at higher settings the deficiencies in frequency response only become all the more accentuated. The sound isn’t terrible, but it’s below what we’ve seen on other comparable machines.

Battery Life

An area of particular interest with regard to this latest Inspiron update is that of battery life. One has to wonder, with dedicated graphics and 4K screen resolutions out of the picture, how much can the Dell improve its runtime?

We unfortunately do not receive a straight answer, as the 7548 we reviewed featured a larger internal battery to help offset the increased power demands of the 4K screen and dedicated graphics adapter. Whereas the 7548’s battery was a 56 Wh model (and the 7537 packed a 58 Wh), the 7558 reduces this significantly to just 43 Wh (the same size as the lower-end 7548 configurations). Along with a smaller 45 W AC adapter, this decision helps to keep the total carry weight of the machine in check.

However, it also has obviously detrimental effects to the total runtimes, which we measure with the assistance of Battery Eater Pro. As a result, apart from the very good max runtime (Reader’s Test, brightness minimum, Airplane Mode) result of 14 hours and 45 minutes and the much-improved load (Classic Test, Max brightness, Wi-Fi On) result of 2 hours, we still managed under five hours total (4:54) on our Wi-Fi Surfing v1.3 benchmark. The surfing benchmark takes place in the default browser for the system, which in this case is Microsoft Edge for Windows 10.

Nevertheless, these results are still all three better than those of the 7548, whose Wi-Fi Surfing score was another half hour shorter (4:24). Considering that this is in spite of a reduction in battery size by nearly 24%, that’s a testament to the power savings the new design changes have sown, even if the benefits are not fully realized.

Minimum runtime (Classic Test)
Minimum runtime (Classic Test)
Maximum runtime (Readers Test)
Maximum runtime (Readers Test)
Wi-Fi Surfing v1.3
Wi-Fi Surfing v1.3
Battery Runtime
Idle (without WLAN, min brightness)
14h 45min
NBC WiFi Websurfing Battery Test 1.3
4h 54min
Load (maximum brightness)
2h 00min
Dell Inspiron 15 7558Dell Inspiron 15-7537Dell Inspiron 15-7548HP Envy 15-k203ngAcer Aspire V15 Nitro VN7-571G-574HToshiba Satellite L50-B-1TD
Battery Runtime
-31%
-23%
-2%
25%
Reader / Idle
885
727
-18%
633
-28%
797
-10%
WiFi v1.3
294
264
-10%
289
-2%
448
52%
Load
120
67
-44%
81
-32%
161
34%
WiFi
392
328
H.264
238
427

Pros

+ Sleek casing and overall good build quality
+ IPS 1080p screen for affordable prices in lower-end configurations
+ Great keyboard with good feedback in spite of a short stroke
+ Good touchpad with comfortably large roughened surface
+ Fast solid-state drive (in our review configuration)

Cons

- Oversized convertible form factor provides few practical benefits
- No dedicated GPU options
- Only one RAM slot (no dual-channel configuration possible)
- Case temperatures can be bothersome under load due to hot spots
- Audible electrical noise while idling
- Battery life is only marginally better than higher-powered predecessors

Verdict

In review: Dell Inspiron 15 7558. Test model provided by Dell US.
In review: Dell Inspiron 15 7558. Test model provided by Dell US.

The Inspiron 15 7558 retreats from the graphics-heavy, RAM-packing philosophy of its predecessors and moves instead in the direction of all-round versatility and novelty. The partially metal casing is still impressive for its class (though not universally solid), with a strong haptic appeal and aesthetic influence that might be more closely compared to a ZenBook than the Inspirons of yore. The conventional input devices are also quite good; the keyboard is comfortable, relatively quiet, and easy to adjust to, and the touchpad, even despite its integrated buttons, is easy to operate with a spacious form factor and comfortable surface finish. The screen could certainly do better with pre-calibration color accuracy and brightness, but it’s at least IPS, and 1080p is the lowest-resolution option available, even on the cheapest configurations ($550). And our review unit’s 256 GB SSD was a blessing, rounding out a reasonable set of specs for a $900 notebook.

The rest of the package is pretty humdrum. Performance is a mixed bag, with strong dual-core CPU capabilities but a complete lack of the dedicated graphics options that previous Inspiron 7000 machines provided. The same goes for system memory; although the amount doubles when moving to the more expensive configurations from the low end (to 8 GB from 4 GB), all configurations are still single-channel, and a second RAM slot does not exist. Case temperatures get a little out of hand in a couple of spots (though thermal throttling does not appear to be a problem).

And for what? Improved battery life? Hardly—the 7558 reduces its battery size appreciably (as compared to the dedicated graphics model of the 7548 we reviewed) to keep its weight in check, which results in only moderately better runtimes than its far more powerful predecessors. What about the new convertible design? Though it’s a headlining feature in Dell’s marketing of the machine, in reality, it is truly just a footnote in its list of functionality, as the machine is too large and cumbersome to serve as a usable tablet or even simply transform on a whim. So the trade-offs are considerable (and the benefits negligible) when moving to the 7558 from the 7548, and the rationale behind the design seems a bit misguided.

Given the relative futility of the Inspiron 15 7558’s oversized convertible design and the magnitude of the other sacrifices involved, apart from cost savings alone, there seems little reason to recommend its purchase over that of its predecessor, the Inspiron 15 7548.

While our review configuration carries a $900 MSRP, a 7548 with Core i7 CPU, 16 GB dual-channel RAM, and AMD Radeon R7 M270 graphics is just $50 more (though it trades the SSD for a notably inferior 1 TB 5400 RPM mechanical drive, which can be swapped in later). For that reason, even in spite of its strengths, we recommend looking around before committing to a purchase.

Dell Inspiron 15 7558 - 09/16/2015 v4(old)
Steve Schardein

Chassis
82 / 98 → 84%
Keyboard
81%
Pointing Device
78%
Connectivity
56 / 80 → 70%
Weight
62 / 35-78 → 63%
Battery
87%
Display
80%
Games Performance
68 / 68 → 100%
Application Performance
84 / 87 → 97%
Temperature
85%
Noise
89%
Audio
50 / 91 → 55%
Camera
68 / 85 → 80%
Average
75%
78%
Convertible - Weighted Average

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> Notebook / Laptop Reviews and News > Reviews > Archive of our own reviews > Dell Inspiron 15 7558 Convertible Review
Steve Schardein, 2015-09-17 (Update: 2015-09-27)
Steve Schardein
Steve Schardein - Review Editor - @othersteve
In grade school, my first computer—an Apple IIGS—started it all for me. Later, in the nineties, if I wasn’t repairing computers for family and friends, I was busy cooking up nifty Visual Basic projects and playing PC games like Command & Conquer and Heroes of Might and Magic. Soon, much of my free time was spent moderating popular gaming forums and covering the industry for various websites. All the while, I never stopped repairing computers, and in 2006, I started a technology consulting company in Louisville, KY—Triple-S Computers—which I have been fortunate to nurture to great success by specializing in not only repairs, but also new machine consultations and purchasing, data recovery, and malware/security. And since 2012, I have proudly contributed many dozens of reviews to Notebookcheck, a site which I have long considered to be the ultimate authority on laptops and related technology. Today, I am truly living my dream: still a child at heart, ever-curious, constantly learning, and thankful to you, our readers.