Verdict: More RAM doesn't mean much more performance.

When a company spins off multiple variants of a single GPU, it's usually because the initial design was flawed in some way. It's certainly arguable that this was the case with the original HD 2600 XT when it was launched seven months ago, which might explain why there are now three HD 2600 XT variants from which to choose.

This variant is the strangest; it has a large 512MB frame buffer, double that of other HD 2600 XTs. However, the RAM is GDDR3, so it's clocked at a mere 700MHz (1.4GHz effective). More RAM should help to improve performance at high resolutions with lots of AA, but the basic HD 2000-series architecture on which the HD 2600 XT is based is very slow at anti-aliasing anyway. Apart from the enlarged frame buffer, this card has the same specs as the other HD 2600 XTs. The GPU has 120 stream processors clocked at 800MHz, but there are only four ROPs.

The extra RAM gave the 512MB GDDR3-equipped HD 2600 XT a slight edge over the 256MB GDDR3 version in our three test games, but the difference was never more than a couple of frames per second. Still, this meant that this HD 2600 XT was able to provide a smooth frame rate at 1,024 x 768 in Call of Duty 4 and Need for Speed: Pro Street.

However, it failed to produce a smooth frame rate in Crysis, so if you want to play this game, you'll have to reduce many of the detail settings.

Although the 512MB GDDR3 version of the HD 2600 XT is slightly faster than the 256MB version, it isn't fast enough to play all the latest games, even at a comparatively low resolution. As such, it's impossible to recommend spending £70 on a card that's next to useless in Crysis, let alone future games that will demand even more powerful hardware.

• Multi-GPU graphics - 20th June 2008
• CPU water cooling - 17th June 2008
• Hard disks - 20th March 2008
• Audio hardware - 29th February 2008
• Graphics cards - 24th January 2008
• CPUs - 21st December 2007
• Motherboards - 13th November 2007

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