If you cast your minds back to before the flooding and general disappointment that we British proudly call our summer, you may recall Riyad's review of the HD 2900 XT - ATI's current flagship graphics card. Among the in depth technical explanations and myriads of graphs there was one little nugget of information that led to a few raised eyebrows both in our office and among technology enthusiasts around the world. Even though the card can use up to 1GB of RAM, ATI was choosing to limit the quota to 512MB, for retail boards. One gig boards were available for OEMs and ODMs, for integration into specialist systems, but the general public weren't going to be able to pick them up in the shops.
The reason given for this was that by reducing the amount of on-board memory, the cost of each card could be kept down, while having a minimum impact on performance. However, although we could see the logic in this decision, it still seemed strange not to allow the option, even if the extra cost didn't give a significant boost in performance. Well, luckily for us all, ATI's board partners have seen the merit of providing such an option to us lowly masses and HD 2900 XTs sporting 1,024MB of memory can now be found from many of the usual outlets.
So, now that you, the buying public, can get hold of these cards, we thought it would be a good time to take a look at one and see whether the extra memory does or doesn't increase performance and, consequently, if ATI was justified in its decision.
As well as increasing the amount of memory on these new boards, the type has also been changed from GDDR3 to GDDR4. This change enables speeds to be increased from 825MHz to 1,000MHz, so, as well as having more memory to access, these cards will be able to talk to it quicker.
Aside from the increase in memory, the HD 2900 XT 1024MB remains exactly the same as its 512MB brother. So, you still get 700 million transistors incorporating 320 stream processors, the super high bandwidth 512-bit memory interface, the as yet unused tessellation engine and all the other goodies I'm sure you're now familiar with. Equally, the change in memory hasn't made a difference to the physical size of the card and it remains 242mm long, 114mm tall, and 39mm deep and looks identical to any other HD 2900 XT.
The particular card I'm looking at is made by Sapphire. As all the HD 2900 XT cards continue to be, it is based on a completely reference design with just a couple of stickers, on the heatsink and one of the power connectors, to distinguish it from the competition. Coming in at £285.48, it is £39.16 more expensive than the 512MB version, which actually isn't a huge premium considering the amount of extra memory you're getting.
Comparing to the competition from nVidia, the GeForce 8800GTS 640MB (the HD 2900 XTs nearest competitor in terms of performance and price) can be had for around £240 while the 8800 GTX is still significantly more expensive with prices averaging around the £330 mark. So, assuming the 1024MB HD 2900 XT can increase performance by a reasonable margin, there is a sizeable gap in the market for it to nestle into.