As previously mentioned, the case comes from the HP Compaq 6720s series, which finds its second home in the HP 550. The lid and the keyboard area is decorated with a shiny titanium-coloured plastic finish, which somewhat mixes up the overall appearance of the system, yet makes it no less business-like. The display area is coloured with a gritty grey plastic up to a shiny black border, and fits smoothly into the "understated" fell of the unit.

Also, the underside is consistent with the gritty plastic design and, along with the rest of the case, can be considered easy to clean and low maintenance. Somewhat puzzling was the claimed weight of the system of 2.5 kg. The system we reviewed weighed 2.29 kg without its battery and with the 6-cell battery it weighed 2.62 kg, which is clearly more. Batteries which are smaller of with fewer cells, which would contribute to a reduction in weight, are not available.

The quality of the case  is barely different from that of our recently reviewed HP Compaq 6735s. The case shows the areas where HP has made further improvements and, conversely, where the HP 550 continues to struggle.

The display of our review HP 550 had a rather displeasing resistance to pressure, and the underside loudspeakers also fell behind. Everything leaves  clear impressions and is at times cringe-worthy due to other shortcomings. Also the layout of the function buttons above the keyboard is unconvincing, as well as the touchpad with different dimensions and protruding areas. The keyboard can be bent and pressurized throughout its entire width, because only some points of it seem to rest on the construction underneath it and nothing else.

In addition, we were quick to criticize the latch for the display which is supposed to hold the chassis and the screen together in transport. Here you can find the ghost of the workmanship of the HP 6735s, which will surely have a negative impact in the long run. We also found it surprising that when the laptop is closed and carried about, the optical drive's tray would give slightly, giving the impression that it is loose. We also found the maximum opening angle of 135° surprising, which is impractical for  working with the laptop on your lap.

However, we appreciated the stability of the device, even without the battery attached, which facilitates the removal and protection of batteries in a network of HP 550 units.

The interfaces are on a level akin to netbooks and all the while very basic. From the rather small interfaces to the Expresscard/54 and the outdated modem interface, the system won't exactly fly away. You also get 3 USB ports, an analogue VGA output, 10/100 Ethernet, a card reader (SD/MMC) and an Audio in/out.

The Broadcom W-LAN module is used for wireless networking, which used the b/g standards. Bluetooth is not an option and if completely necessary must be provided by an external solution. Faster connections like Firewire, eSata or typical business connections  are not included and must instead be compensated for by USB or ExpressCard alternatives.

HP offers consumers a variety of warranty-extension options and accessories on its Homepage, whose prices are, taking account of the price of the system, not justified.

The positioning of the USB ports on the left-hand side was seen in a negative light. While in theory there are three USB connections, as soon as you plug in a device with excessive width, such as UMTS or DVB-T equipment, you'll find that one connection is blocked by the other. In this case, you would need USB extension cables in order to make comfortably use three USB devices.

Also, it's only possible to use the ExpressCard port with USB devices underneath with an extension. Again, due to the small gaps between the interfaces, such limitations cause the system to fare considerably poorly. Successive models have at least partially resolved the problem by placing two additional USB ports on the right-hand side.

The HP 550 is, as previously mentioned, only available in one configuration and this is also true for the Bright-View  WXGA Display  with an aspect ratio of 16:10.

The panel is from LG/ Philips  and has a resolution of 1280x800 pixels, which is standard of 15.4“ screens. The overall good contrast of the earlier glare displays  is not attained by many newer models. This is true for this display which, with a contrast ratio of 184:1, is below par. As usual, this is to be seen in the low saturation of colours in the palette of pastel colours.

The brightness values and illumination give a considerably better picture of the system. With an average of 196 cd/m² and a brightness distribution of 80,5% the display gives good values and as a result the system shouldn't hide behind its significantly more expensive rivals.

Although the system isn't designed so much for outside use, on the inside the high brightness values can at least compensate for the reflections caused by the display's glossy surface in unfavourable lighting conditions. However, the darker the image and the brighter the ambient light, the more obvious the reflections become.

Ubuntu Linux

For bargain hunters who have no Windows OS installation CD at hand, a variety of Linux distributions are available. For testing purposes we have used the popular Ubtunu 8.1 which we were very impressed by.

The HP 550 is equipped with a Celeron M 550 CPU (2.0 Ghz / 533 Mhz FSB/ 1 MB L2 Cache) , 1GB RAM, an Hitachi 160GB hard drive and Intel GMA X3100 integrated graphics. As a basis for the slimmed-down  Intel GL960 chipset a maximum of 2GB RAM is allowed. This was confirmed when an additional 2GB module was inserted, resulting in a system crash.

How powerful is our configuration? The system had somewhat sobering scores. The system achieved 2363 points in PC Mark`05 and 243 points im 3D Mark 06 which makes for no wonder laptop. With an additional 1GB of RAM we measured 2417 points in PC Mark`05 and 266 points in 3D Mark`06), which means that an extra GB makes only marginal differences and are within  the margin of error. However, some Photoshop actions are clearly more fluid with more RAM.

Whilst the current benchmark results give a clear comparison with other current notebooks, many applications like Office, the internet and modest picture editing feel surprisingly fluid. As soon as you try to run a number of applications at the same time, however, such as an anti-virus program and an internet browser with several windows open, you notice the lack of a second core which would relieve the load on the CPU. The X3100 is not at all capable of dealing with 3D-heavy applications like 3D games, 3D animation or CAD work. Whilst old games without demanding graphics requirements like Stronghold, The Settlers or Age of Empires are still playable, this system should be avoided if you have professional applications in mind.

The 2.5" Hitachi 5400 rpm hard drive with a transfer rate of 47.1 Mb/s delivers acceptable results. With 160GB the hard drive is relatively large and should be able to provide for many home-office applications.

The LG optical drive, which has in addition to the standard read/write function a Lightscribe function, has a relatively average read/write speed just like the HP 6735s's Samsung drive, but otherwise it works quietly and should satisfy most people.

Overall, the performance of the HP 550 is still much better than many of its similarly priced netbooks with Atom architecture. However, it is much slower  than the better-equipped dual-core notebooks 

System Noise

The overall operating volume for most uses is 34 dB(A) which is a quiet yet noticeable level. If you are using undemanding applications for word processing, spreadsheets or simple picture editing or internet tasks,  the fan is at level one, where no noise comes out.

What we considered negative and surely not to everyone's taste was the fan which would turn on and off every 20 to 30 seconds. A more consistent pattern would certainly be more pleasant.

The noise level increases to 36.5 dB(A) during DVD playback due to the optical drive and when you really put the pressure on the HP 550 the volume increases to 38.4 dB(A) which isn't as unpleasant as you would think.