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The Kaby Lake-G Core i7-8705G offers no substantial benefits over the Core i5-8305G

The Kaby Lake-G Core i7-8705G offers no substantial benefits over the Core i5-8305G (Image source: Dell)
The Kaby Lake-G Core i7-8705G offers no substantial benefits over the Core i5-8305G (Image source: Dell)
Based solely on our two XPS 15 9575 samples, the presence of Hyper-Threading for the Core i5 series has allowed the 65 W i5-8305G to perform much more closely to the 65 W i7-8705G than one would expect. This is in stark contrast to the older 45 W i5-7300HQ where the 45 W i7-7700HQ and even the 15 W i7-8550U can outperform it in multi-threaded workloads. Shoppers now have one less reason to buy the more expensive i7 over the i5.

Intel's Kaby Lake-G platform is now out in the wild... sort of. We finally have benchmarks on the Core i5-8305G and Core i7-8705G courtesy of Dell and its XPS 15 9575 series since these convertibles are some of the first systems to carry these processors. So, is there an appreciable performance difference between the two CPUs?

A quick glance at their core specifications shows very few differences between the i5-8305G and i7-8705G as summarized by the table below. The 300 MHz delta in clock rates means little in notebooks where throttling and thermal management are often priority over sustaining the maximum rated frequencies. Most notably, however, the Core i5 Kaby Lake-G CPU supports Hyper-Threading for a total of 8 simultaneous threads. This small fact narrows the performance gap between the i5-8305G and i7-8705G to just 10 percent at best in single- and multi-threaded loads.

CPUFamilyCore/ThreadL3 CacheTDPBase FrequencyTurboiGPU
Core i5-8305GKaby Lake-G4/86 MiB65 W2.8 GHz3.8 GHzAMD Radeon RX Vega M GL
Core i7-8705GKaby Lake-G4/88 MiB65 W3.1 GHz4.1 GHzAMD Radeon RX Vega M GL
Core i5-7300HQKaby Lake4/46 MiB45 W2.5 GHz3.5 GHzHD Graphics 630
Core i7-7700HQKaby Lake4/86 MiB45 W2.8 GHz3.8 GHzHD Graphics 630

In comparison, the Core i5 Kaby Lake HQ series for laptops do not support Hyper-Threading. As a direct result, the popular Core i5-7300HQ found in mainstream gaming notebooks like the Inspiron 15 7577 can be 30 to 40 percent slower than the common Core i7-7700HQ. Intel's decision to include Hyper-Threading for the Core i5 Kaby Lake-G series brings the Core i5 much closer to the i7 than in the previous generation.

The results can be seen as a double-edged sword for the consumer. On one side, users can purchase laptops with the i5-8305G CPU knowing full well that it can perform nearly as fast as a more expensive i7-8705G configuration. On the other hand, it's a shame that the i7-8705G offers no significant CPU or GPU benefits over the cheaper i5 option.

A larger sample size will be needed before we can definitively label the Core i7-8705G as only a minor performance boost over the i5-8305G. Given that Kaby Lake-G laptops are so rare, however, the XPS convertible is our only look at the two processors thus far at least until the launch of the 2018 HP Spectre x360 15.

We recommend checking out our reviews on the Core i5 XPS 15 9575 and Core i7 XPS 15 9575 for more benchmarks and information.

Cinebench R15
CPU Single 64Bit
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
178 Points ∼82%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
174 Points ∼80%
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
157 Points ∼72%
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
150 Points ∼69%
Dell Inspiron 15 7000 7577
Intel Core i5-7300HQ
134 Points ∼61%
CPU Multi 64Bit
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
864 Points ∼20%
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
728 Points ∼17%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
699 Points ∼16%
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
681 Points ∼16%
Dell Inspiron 15 7000 7577
Intel Core i5-7300HQ
507 Points ∼12%
Cinebench R11.5
CPU Single 64Bit
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
1.99 Points ∼82%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
1.97 Points ∼81%
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
1.79 Points ∼73%
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
1.72 Points ∼70%
Dell Inspiron 15 7000 7577
Intel Core i5-7300HQ
1.53 Points ∼63%
CPU Multi 64Bit
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
9.41 Points ∼28%
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
8.1 Points ∼24%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
7.65 Points ∼23%
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
7.47 Points ∼22%
Dell Inspiron 15 7000 7577
Intel Core i5-7300HQ
5.85 Points ∼17%
Cinebench R10
Rendering Single 32Bit
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
6668 Points ∼62%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
6436 Points ∼59%
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
5844 Points ∼54%
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
5716 Points ∼53%
Dell Inspiron 15 7000 7577
Intel Core i5-7300HQ
5147 Points ∼48%
Rendering Multiple CPUs 32Bit
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
25809 Points ∼52%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
23794 Points ∼48%
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
21986 Points ∼44%
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
21845 Points ∼44%
Dell Inspiron 15 7000 7577
Intel Core i5-7300HQ
17806 Points ∼36%
wPrime 2.0x - 1024m
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
215.823 s * ∼3%
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
211.977 s * ∼3%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
197.647 s * ∼2%
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
186.66 s * ∼2%
Super Pi Mod 1.5 XS 32M - ---
Dell Inspiron 15 7000 7577 4K
Intel Core i7-7700HQ
594.032 Seconds * ∼3%
Dell XPS 15 9575 i5-8305G
Intel Core i5-8305G
564.887 Seconds * ∼3%
Dell XPS 15 9575 i7-8705G
Intel Core i7-8705G
503.967 Seconds * ∼2%
Intel Hades Canyon NUC8i7HVK
Intel Core i7-8809G
484.864 Seconds * ∼2%

* ... smaller is better

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Cinebench R15 CPU Multi 64 Bit Loop Test (XPS 15 9575, Core i7-8705G)
0102030405060708090100110120130140150160170180190200210220230240250260270280290300310320330340350360370380390400410420430440450460470480490500510520530540550560570580590600610620630640650660670680690700710Tooltip
Cinebench R15 CPU Multi 64 Bit Loop Test (XPS 15 9575, Core i5-8305G)

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> Notebook / Laptop Reviews and News > News > News Archive > Newsarchive 2018 05 > The Kaby Lake-G Core i7-8705G offers no substantial benefits over the Core i5-8305G
Allen Ngo, 2018-05- 8 (Update: 2018-05- 9)
Allen Ngo
Allen Ngo - US Editor in Chief
After graduating with a B.S. in environmental hydrodynamics from the University of California, I studied reactor physics to become licensed by the U.S. NRC to operate nuclear reactors. There's a striking level of appreciation you gain for everyday consumer electronics after working with modern nuclear reactivity systems astonishingly powered by computers from the 80s. When I'm not managing day-to-day activities and US review articles on Notebookcheck, you can catch me following the eSports scene and the latest gaming news.