The IBM ThinkCentre S50 Ultra Small is the world's smallest 'full-function' desktop computer according to manufacturer IBM. Whether it's the world's smallest or not, it's certainly one of the smallest we've seen.

For a business-oriented product the S50 is unusually stylish. The fascia consists of spiffy honeycomb ventilation holes and the black paintjob is also much in keeping with IBM's own notebook range. The thick steel casing is very rugged, and is designed to hold even the chunkiest monitor. It was designed tough to withstand accidents and scrapes and is definitely sturdy enough to handle a fair share of hard knocks. Weighing in at 6.4kg, the unit is relatively heavy for a small form factor box. A quick peak inside reveals why: a large copper heatsink covers the 3GHz Pentium 4 processor, and the case is full of steel bracing and drives.

In the graphics department, the S50 sports Intel's 865GV graphics chipset. With no DVI output available, you'll need to output all digital video signals through a standard VGA port. Furthermore, with no AGP port you won't be upgrading this to a games or entertainment machine any time soon. The lack of graphics expansion, combined with the 64MB of shared onboard video, further cements the S50 in the realm of business desktops.

The ThinkCentre is a tool-less design, manufactured to allow quick access to the hard drive and other components. There are two pinball-like toggles at each side of the case which, when pressed together, open the unit like a Lamborghini gull wing door.

Inside, a series of purple plastic tabs and handles enable you to quickly dismantle the PC. The internals are very tidy, and the cables fold down neatly into a little cavity when reassembled. A single PCI slot doesn't leave much room for expansion, however. The single 512MB stick of DDR400 RAM is easily accessible beneath the 40GB hard drive if further expansion is necessary.

Cooling is important in small form factor PCs and the S50 takes care of this with three case fans: two intake, with one passing air directly through the CPU heatsink, and the second servicing the 200W power supply; while the third is a small exhaust fan. Despite the number of fans, the machine is very quiet and well suited to office environments.
There are plenty of I/O options with a total of six USB ports, two microphone jacks, and two headphone jacks. The included Teac-224E optical drive is a bit of a disappointment, however. It's CDROM only - no writing ability - and is a small notebook-style unit, so any burning upgrades are limited.

IBM has spared some thought for external storage though, the front USB ports are spaced specifically to accommodate most USB memory keys, but considering the price of CD-RW drives this seems like an oversight. The next model up doesn't offer the expected writeable media option either - just a small increase in processor speed from 3.0 to 3.2GHz.

As far as performance is concerned, the ThinkCentre performed well. It managed 225 in SYSmark2002 that is more than enough for day-to-day business needs as well as the grunt to handle extra tasks.

Not surprisingly though the S50 is no multimedia monster. It has a small built-in speaker that is also very quiet, but the included headphone/speaker jacks help remedy this.
The version we received came with the optional ThinkVision IBM L150 15in TFT, which complements the box both in style and minimalist functionality. It has large, intuitive controls and a bright clear screen, with only a little yellow discolouration when not viewed from directly in front. But this is typical of an LCD screen.

The monitor comes with an Auto Image Setup button that worked well in smoothing out some of the darker patches on the screen.

All in all, a great dedicated office desktop, and with no DVD, gaming, or serious multimedia capability there's little distraction for workers. For under two grand, including 15in monitor, the ThinkVision offers good value and performance for money.