Arbico's OC 4870 XL might not have the striking looks of Acer's Predator Trooper, but its plain black case belies the power that this PC has to offer. And, as always, it's what's inside that really counts.

The OC 4870 XL has been built inside an XClio Coolbox case, which looks rather slab-like, but has one very obvious strength: two huge 180mm fans are fitted. One of these is situated on the front, the other on the side, with the end result being that a decent amount of air can be drawn across the components inside without making too much noise. A simple rotary fan controller is fitted, so you can find a balance between cooling and quietness, although you'll have to reach around to the back panel to use it.

Two USB ports, along with headphone and microphone sockets, are positioned rather awkwardly on the very bottom of the case's front panel. A DVD writer is fitted above, as is a multiformat memory card reader that includes a single, but more usefully positioned, USB port.

Spin the case around, though, and you'll find a more useful collection of sockets: another eight USB ports, digital and analogue audio sockets and Gigabit Ethernet. The abundance of audio sockets points to an unexpected bonus – as well as the Realtek audio chip included on the motherboard, Arbico has added a Creative X-Fi Xtreme Audio soundcard.

Inside the case, however, is where things get interesting. The first thing you notice is that, rather than using a standard Intel cooler, Arbico has fitted an Arctic Cooling Freezer 7 Pro. This has a huge heatsink and a quieter fan, and has allowed the company to overclock the Core 2 Duo E8500 processor fitted underneath it to 3.8GHz. The memory installed is 800MHz DDR2, with 4GB fitted as two 2GB modules made by Corsair.

A 500GB Samsung hard disk is included in the front of the case. This seems a rather pedestrian choice when compared to some of the other components included but, with six free Sata ports on the motherboard, it would be easy to add more storage in future if needed. A sizeable chunk of the OC 4870 XL's cost has, unsurprisingly, been spent on the graphics card. The Gigabyte GA-EP35-DS3R motherboard has a single PCI Express x16 slot, which is filled by a 512MB ATI HD4870 card.

The system produced impressive results in our benchmark tests. Its score of 5.7 in the Windows Experience Index is higher than that of the £1,700 Acer Predator, and it produced 5,484 points in the demanding PCmark Vantage test. The single ATI graphics card held up well in 3D tests, too, notching up a score of 15,604 in 3Dmark06 – just moving in front of the Geforce 8800GT-powered Chillblast Fusion Sentinel, which scored 13,822. More impressive still, it produced an average of 45fps (frames per second) in our World in Conflict test – the Acer Predator, equipped with two Nvidia cards in SLI, averaged just 38fps.

No monitor, keyboard or mouse is included with the OC 4870 XL, making it most suitable for those wishing to replace an older computer. It faces stiff competition from the Chillblast Fusion Sentinel, which includes a quad-core processor and costs £100 less, but then it did produce slightly better scores in our 3D benchmarks. All in all, the OC 4870 XL may not be particularly pretty, but this is a powerful computer ideal for gaming, at a reasonable price.