R600: ATI Radeon HD 2900 XT

Final Thoughts...

The wait is finally over! R600 is finally shipping to customers – I was starting to think that it’d never happen, but somehow it’s finally made it out of the door. It’s been one of the most anticipated hardware releases for some time, but unfortunately it doesn’t quite live up to our expectations.

First off, the card is obviously late. Very late. And normally when you’re late, you have to do something special. Unfortunately for AMD, R600 just isn’t that special because not only is Nvidia’s performance crown still intact, the card AMD has chosen to attack – the GeForce 8800 GTS 640MB – has come away with all but a few chinks in its armour.

That’s not to say that R600 is a particularly bad card, it’s just not going to set the world on fire (well, it depends which way you look at it – Ed.) when it comes to performance. There are undoubtedly scenarios where it does perform fantastically and much to our surprise one of those scenarios is OpenGL – a territory that was once an Nvidia fortress. Not anymore, it would seem.

In particular, shader heavy scenarios can, if written to take advantage of AMD’s VLIW architecture, show truly outstanding performance. It’s not clear which way game development is going to go, but shader load is only going to increase if the past is anything to go by. The question is how the shader load is going to increase though and whether we’re going to see it increase with deeper instructions, or wider instructions. The latter would obviously suit ATI’s R600 architecture more, but it essentially doesn’t matter which way it goes for Nvidia – its hardware will allocate the required resources, regardless of whether the shader instruction is long, or wide.

There’s also still the question of DirectX 10 performance to be answered. There are DirectX 10 performance numbers on the web if you search for them – we have the same code here. We’ve actually got two DirectX 10 ‘demos’ in-house now, but one is supplied by AMD and the other is supplied by Nvidia – neither could be called ‘independent’ and neither company wants you to run one or the other on its hardware for whatever reason.

Basically, DirectX 10 performance isn’t going to become clear until we actually see retail code that you can go and buy in your local video games store. Hopefully, that’ll happen later this month, fingers crossed. At that point, we’ll be able to quantify the kind of performance you’re likely to get in DirectX 10 games based on independent code.

The other thing that needs to be mentioned is that R600’s current anisotropic filtering quality isn’t up to the standards we’ve come to expect from ATI hardware. Hopefully the problems are just related to the current driver release, but even if that is fixed, it will not be up to the quality standards delivered by Nvidia’s G80 graphics chip. That makes Nvidia’s angle-independent anisotropic filtering hardware all the more impressive.

On the positive side, there are some great innovations in the architecture too, so it’s not all doom and gloom. In particular, the on-board audio solution is an interesting one that warrants a closer look, and the dedicated tessellation hardware is also going to be a big feature moving beyond DirectX 10. In many ways, it’s a feature not too dissimilar to the GeForce 6-series’ Shader Model 3.0 support. There weren’t really any games out there that made use of the new feature, but it sure sold Nvidia a massive number of GeForce 6-series graphics cards.

The same is true with the tessellation hardware in R600, but there are many games making use of the Xbox 360’s dedicated tessellation unit, so what’s stopping developers porting these games over to the PC? I’m not the biggest fan of console ports, but XNA is a great software development kit that helps console developers get the most out of their ports to the PC. There’s obviously a chance that these developers would port over the tessellation features they’re using in the Xbox 360 versions of their games, but we don’t think PC games using tessellation will show up long before Nvidia has the same features in its hardware (the same was true with the X1000-series and SM3.0 games).

Final, Final Thoughts...

AMD’s Radeon HD 2900 XT has some neat innovations but it ultimately falls short of our expectations. It’s been a long time since we’ve been able to associate the word “leading” with ATI graphics hardware and we’re going to have to wait even longer before we’re able to say it. Thankfully though, ATI hasn’t priced its Radeon HD 2900 XT out of the market, but supply shortages are pushing prices up at online retailers. Once the supply settles down, the cards should be available for around £250 (inc VAT), whereas today they’re available for almost £300!

In comparison, Nvidia’s GeForce 8800 GTS starts at £215 (inc VAT) for a standard model, and the BFGTech models we’ve used in this comparison retail for just over £250 (inc VAT). At the moment, the GeForce 8800 GTS 640MB is the better buy and those that bought one shouldn’t be disappointed. If you’re looking for the fastest and second fastest graphics solutions on the market, the GeForce 8800 GTX and GeForce 8800 Ultra still hold those titles. Look out for some more R600 coverage in the next few days...

• Features
• x
• x
• x
• x
• x
• x
• x
• x
• x
• x
• 10/10

• Performance
• x
• x
• x
• x
• x
• x
• x
• x
• -
• -
• 8/10

• Value
• x
• x
• x
• x
• x
• x
• -
• -
• -
• -
• 6/10

• Overall
• x
• x
• x
• x
• x
• x
• x
• -
• -
• -
• 7/10

What do these scores mean?