If you can sit back and reminisce with me for just a bit, the date was early in 2007 and the world was a-flutter with rumors of ATI's R600 GPU architecture. The rumor mills were in full swing and both a Radeon HD 2900 XT and XTX were said to be in the works. The difference? Well, 1GB of GDDR4 memory on the XTX and 512MB of GDDR3 on the XT version. But when the product finally launched in May, there was no XTX model to be seen and the top end Radeon HD 2900 XT did indeed have 512MB of GDDR3 on-board memory. That left many of us wondering what happened to the Radeon HD 2900 XTX model and the 1GB revision we were looking forward to. - PC Perspective

Diamond Viper HD 2900 XT 1GB GDDR4 Card Review

AMD basically told us nothing of the matter and it wasn't until the end of June when the idea popped up again; this time Diamond was the source. They were going to be sending us a pair of these illusive 1GB versions of the Radeon HD 2900 cards. Still called the Radeon HD 2900 XT, would the added memory and memory speed be enough to help AMD's product against the ever tightening grasp of NVIDIA's GeForce 8 series of graphics cards? Cause in the end that is where it all comes down to, taking the lead, crushing the benchmarks scores and to be the king of the hill once again.

The R600 architecture is a major step beyond the R580 architecture we saw in ATI's Radeon X1900 XT graphics cards and lineup that jumps down the road of unified shaders, a route required by Microsoft's DirectX 10 and first implemented in the G80 architecture from NVIDIA. AMD claims that the new Radeon HD 2000 series of graphics cards will take the best features of the Radeon X1000 series, like dynamic branching and combine them with advantages from the Xbox 360's Xenos GPU, such as unified shaders and add new technology like DirectX 10 support, a superscalar shader processor to make a truly amazing product.

Somewhat disappointingly, the Diamond Viper HD 2900 XT 1GB card looks just like any other Radeon HD 2900 XT card we have seen hit the streets. Same cooler, same color, same everything. You would be hard pressed to look at the card and not just think it's a standard 512MB card, something that we think Diamond should have done differently. If you are willing to fork out for the added prestige a 1GB card should offer, you should get a little more bling for your buck. The core clock is about on par with the reference clock of 740MHz but the memory clock is significantly faster than the reference speed of 1650MHz.

The only unseen change, and the only change really, is the addition of more memory chips; GDDR4 is the type and 1GB is the capacity. This is of course twice as much as the 512MB version of the Radeon HD 2900 XT cards currently for sale elsewhere and slightly more than the 768MB that the GeForce 8800 GTX cards are equipped with. The competing GeForce 8800 GTS models come in both 640MB and 320MB flavors. Integrated CrossFire is included as well on the Diamond Viper HD 2900 XT, and may we remind you all that both connectors are required for CrossFire to function correctly.

The new Diamond Viper HD 2900 XT 1GB graphics cards definitely have the initial appeal to hardcore gamers by simply having the first 1GB consumer card on the market. In general, more memory is always better, but how much better today, and how much better tomorrow? For a large majority of our testing, the performance of the Diamond Viper HD 2900 XT 1GB was a bit of a letdown for two reasons. First, this is still the same Radeon HD 2900 XT GPU that we saw back in May with the R600 launch and nothing has changed since. The card does pretty well, though at the price point it doesn't have a real advantage.

The second problem that Diamond faces with the 1GB model is that, in most of our tests, doubling the amount of memory to 1GB and moving to GDDR4 versus GDDR3 modules didn't have a dramatic effect on performance. Certainly it had much less impact than I had initially hoped to see. Yes the Diamond Viper HD 2900 XT 1GB graphics card does perform slightly better than the reference platform 512MB version. It is also likely that the 1GB model will be better suited for the future of games on the PC later in the year. Or that you could get a GeForce 8800 GTX card for just some dollars or so more?

Diamond is definitely putting themselves out on a limb by selling and promoting an AMD graphics product that AMD themselves decided not to launch. By doing so Diamond is hoping to make a name for themselves as being the high-end enthusiast level partner for AMD's products now and going forward but they might be biting off more than they can chew with this current offering. The Diamond Viper HD 2900 XT 1GB graphics card would make a fantastic choice for any gamer looking to get the best technology for today and tomorrow but it is definitely not the only option.