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If your top priority when choosing a Windows 7 PC is performance, Scan’s 3XS P55 OC should be near the top of your list. It may have the same Intel Core i5 750 as many of its rivals, but Scan has squeezed every last ounce of power out of it through overclocking. This makes it the fastest Core i5 PC we’ve ever reviewed, running at 3.67GHz, 400MHz faster than the maximum turbo boost speed of this processor. Unsurprisingly for an overclocked PC, a huge cooler dominates the compact case. All fans are remarkably quiet, though, and the 3XS is barely audible when idle. Unfortunately, the cooler renders one of the PCI-E x1 slots useless and because the 120mm fan sits right over the top of the memory, you’ll have to refit it if you want to install extra RAM into the spare slots. You’re limited to standard-height memory, so modules with elongated cooling fins are out. We like the Corsair power supply, though. Its modular, flat power cables are neatly routed around the case without obstructing anything. The MSI P55-GD65 motherboard has a second PCI-E x1 slot, but this is blocked by the double-height Nvidia GeForce GTX 275 graphics card. There’s an accessible PCI-E x4 slot, though, as well as two PCI slots and an additional PCI-E x16 slot. You can use the latter for any PCI-E expansion card, or add a second Nvidia 275. The motherboard supports ATI CrossFire as well as Nvidia’s SLI. Scan usually sells PCs without a monitor, keyboard and mouse, but for this review it bundled an Iiyama ProLite E2208HDS 22in widescreen display, which is bright and sharp. You also get an excellent Logitech G5 gaming mouse and a G15 keyboard. The keyboard is superb for typing and gaming, and there are extra programmable function keys for gaming.
The 3XS P55 OC is insanely fast – quicker than some Core i7-equipped PCs. Scan provides a full one-year warranty, so you don’t have to risk damaging expensive hardware by attempting to overclock a PC yourself. At £1,142, the P55 OC is a good choice if you want the very best performance, but you’re paying for the privilege.