It has been a few months now since AMD lifted the lid on their high-end Radeon HD 2900 XT graphics board, finally bringing some competition to the DirectX 10 market that NVIDIA have dominated alone for what seemed like an eternity beforehand. To say that the Radeon HD 2900 XT's reception was luke warm is probably putting it mildly. With no parts to put up against NVIDIA's flagship GeForce 8800 GTX and Ultra boards, and the Radeon HD 2900 XT itself barely keeping pace with the GeForce 8800 GTS, many a doom laden opinion about AMD and ATI were being bandied around the enthusiast community. But the battle isn't over yet with ATI working hard on better drivers. - Elite Bastards

PowerColor Radeon HD 2900 XT 512MB Card Review

However, despite all that we all know that a few months can, on occasion, make quite a difference to graphics board performance, as drivers have their kinks ironed out and performance and features improved. So, now the Radeon HD 2000 series is a few months old, what better time to revisit ATI's flagship GPU? As a basic recap though, ATI's Radeon HD 2900 XT is powered by their flagship R600 core, a 700 million transistor behemoth manufactured on TSMC's for high speed 80 nanometre process. Contained within that vast core are 320 shader processors which make up the DirectX 10 capable unified shader architecture.

PowerColor's Radeon HD 2900 XT board is based entirely on the reference specification from clock speeds to cooler - As we just covered, that means a core clock of 740MHz, with GDDR3 memory clocked at 1650MHz. PowerColor's offering features that flame imbued, dual slot cooler, which sits atop the large heatsink with two heat pipes that cover the R600 GPU core. CrossFire is supported via two inter-GPU connectors, and the required power to run the board comes via a combination of a 6-pin and 8-pin PCI Express connectors, which is required for extreme overclocking.

It's time to investigate its overclocking capabilities. To do this, we've stuck to using ATI's own in-driver Overdrive tool to set clock speeds under Catalyst 7.8, using the relevant power supply with both 6-pin and 8-pin PCI Express power connectors. Starting with the core, we managed to garner just over another 85MHz out of our sample board, leaving us with a final stable core clock speed of 830MHz. Memory clocks didn't respond quite so well to our overclocking efforts, as we found ourselves with a stable increase of 120MHz, giving a final memory clock of 1780MHz effective.

With all of the negative press surrounding ATI's flagship part since its release, it's easy to lose sight of the proverbial wood for the trees. It sometimes takes an article like this to remind you that, in fact, the Radeon HD 2900 XT is an extremely competitive part compared to NVIDIA's offering at this price point, the GeForce 8800 GTS 640MB. Without anti-aliasing involved, R600 is an absolute giant performance wise, a facet which is sadly let down by its large performance drops with multi-sampling enabled, giving the opportunity for its major rival to catch up and, on occasion, overtake it.

So, at the end of the day, PowerColor's Radeon HD 2900 XT is an impressive performer, if you're one of those rare people who has no interest in anti-aliasing, then it's simply a must buy for its price. Viewed in isolation, the Radeon HD 2900 XT 512MB is an excellent piece of hardware, but once you put it up against the GeForce 8800 GTS 640MB it becomes a more difficult sell. Performance is equal to NVIDIA's offering, but ultimately the heat and noise output coupled with the board's power requirements makes it a little less tempting.