For those unfamiliar with the concept, a workstation is really little more than a PC with enough low-down processing grunt and graphics capabilities to cope with CAD/CAM and other demanding applications. Market leaders have long been Sun, HP and Dell but Lenovo is keen to climb up the pole with its revamped range of ThinkStations, powered by Intel's latest Xeon quad-core processors.

First impressions are good, the ThinkStation S20 showing its IBM heritage in the form of an exceptionally sturdy tower casing, tool-free access and a really neat internal layout with plenty of cooling. Despite which the S20 is quiet in use, becoming almost eerily silent when idle. Added to which it has a lot of green credentials, the S20 conforming to the latest Energy Star specifications as well as being made from over 50 percent recycled plastic.

A number of different Intel Xeon processors can be specified, mostly quad-core but with the odd dual-core as well if preferred. The review system came with a mid-range E5506, a quad-core chip clocked at 2.13GHz, with an 800MHz DDR3 memory controller and 4MB of cache. For really demanding applications, however, you can specify the 2.53GHz E5540 with a 1066MHz memory controller and 8MB of cache, or the even quicker 3.2GHz W5580 (1333MHz and 8MB).

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DDR3 memory is the order of the day with 4GB installed in the review system, occupying two of the available six DIMM sockets. Up to 12GB can be supported altogether and there's a choice of dual-display video cards, mostly from Nvidia's Quadro line-up, but with ATI FirePro if preferred. Moreover it's possible to fit two adapters in the PCI Express x16 expansion slots provided, and support up to four monitors in total.

The storage options are reasonable if a little disappointing, with a choice of 250GB or 500GB SATA hard disks on the base models. Ours had just one 500GB drive (a 7,200rpm Seagate Barracuda) leaving two 3.5-inch bays for expansion. RAID is more or less a must-have on this type of workstation and there's support for Level 0, 1, and 5 setups on the motherboard, but with a maximum of three internal disks you're a bit limited and might need to add a plug-in host bus adapter and external drives to beef up this part of the S20 equation.

On the plus side you do get an eSATA port for external storage expansion, together with the usual DVD burner plus room and an interface for one other, if needed. A Gigabit Ethernet port is also built in, plus a set of eight USB 2.0 connectors, a 20-in-1 card reader and comprehensive analogue and digital audio capabilities.

On the software front it's either Windows Vista or XP, 64-bit implementations of which can be factory installed with minimal 'bloatware' beyond backup and security utilities, and a trial version of Office 2007.

The keyboard and mouse are nothing special and there's no monitor unless otherwise ordered. In terms of price, however, it matches and in some cases beats what the other workstation vendors have to offer. Moreover, if you've deep pockets there's a dual-socket version, the ThinkStation D20, delivering up to 8 cores and SAS storage, which is about as quick as you're likely to get at present.

With a choice of fast quad-core Xeons, masses of RAM and powerful Nvidia or ATI graphics, the Lenovo ThinkStation S20 is well placed to cope with just about any application you'd care to throw at it. High build quality and green credentials also commend it to workstation buyers, the only disappointment being a dearth of storage options.