How to Make a Mac Killer

How We Chose Our Kit

Hard disk: 750GB Samsung SpinPoint F1 HD753LJ £56.91 (inc. VAT)

Clearly, someone at Apple’s HQ in Cupertino is an avid Custom PC reader, as the company uses the 640GB Western Digital Caviar Blue in the iMac - a drive that is on CPC's Elite list. We were tempted to follow suit but decided on something slightly bigger, so we went for a favourite of the bit-tech and Custom PC team, Samsung’s SpinPoint F1, in its 750GB form.

It’s 110GB larger than the iMac’s disk, and although you can pay an extra £80 for a 1TB drive when buying your iMac, you can’t upgrade it yourself. The Western Digital is slightly faster than the Samsung, with an average access time of 12.5ms compared to the Samsung’s 13.6ms. The Samsung’s average read time is also slower, but it was faster in our game level loading test, and comparable in the image editing test.

Graphics: Sapphire Radeon HD 4870 Toxic 1GB £166.72 (inc. VAT)

While Apple has the advantage in the sleek looks department, the PC has the advantage when it comes to gaming power. The iMac’s laptop origins might restrict CPU choice (you can’t, for instance, buy a quad-core iMac) but GPU choice is where Apple’s machine really suffers. The GT 120 is better known as the lowly GeForce 9500 GT with 256MB of 600MHz (1.2GHz effective) memory, a meagre 64-bit memory interface and 32 stream processors.


There’s no way this card will be able to game at the native resolution of the iMac’s 24in screen, and you should take the Apple website’s description of it as ‘Ultrafast Nvidia graphics’ with not so much a pinch of salt, but a Hercules C-130 fully loaded with salt. When buying your iMac, you can upgrade the graphics, but the best you can have is a Radeon HD 4850, and this will cost you £160 – £50 more than if you were to buy the desktop version of the card from a retailer.


While we were confident that we could easily trump the Apple machine for graphics power, we had to be aware of noise levels. The iMac’s mobile GPU is a trump card here, as its cooler produces very little noise. For this reason, we opted for the 1GB version of Sapphire’s extremely quiet Radeon HD 4870 Toxic. The 92mm fan spins very quietly, while its vapour chamber technology helps to cool the GPU 19˚C lower than the reference cooler. This card has fallen in price considerably since we saw it a few months ago, and it will bring solid performance and low decibel levels to our iMac killer.

Display: HP LP2475W £436.60 (inc. VAT)

Apple is quite conservative with the specification of the iMac display on its website; whether this is out of embarrassment due to the quality of the panel or an attempt to keep its site free of numerical clutter is hard to say. The contrast ratio of the 24in iMac display is 750:1, 25 per cent less than the 1,000:1 contrast ratio of the Labs-winning 24in HP LP2475 that we’ve enlisted for the job. Selecting a display that’s as attractive as the iMac is practically impossible; instead, we chose a display that has proven capable of producing stunning visual gorgeousness.