ATI CrossFire - Hands on

Economics

This is where it really gets complicated. There are several questions we think you guys should have the answers to.

1. I have an AGP system and I want to upgrade. Should I go to NVIDIA or ATI when considering multiple cards?
2. I have an ATI card on PCI Express already. Should I plump for CrossFire?
3. How does the current CrossFire solution compare to a single Nvidia 7800?
4. How will next generation CrossFire compare to 7800 SLI, and how does R520 affect me?.

All of these questions involve issues of cost as well as performance. Let's try and answer them.

1. I have an AGP system and I want to upgrade. Should I go to NVIDIA or ATI when considering multiple cards?

Current generation: So... a X850 XT can be had for £230. A Master Card will be around £250, but both will possibly see a price cut in the next week or so, so we'll say £400 for that pair. CrossFire motherboards will be available at around £100, so the solution will cost you £500 (to our North American readers: substitute pricing as appropriate, but follow the logic...)

A 6800 Ultra can be had for £210, and again, another £100 for the board. This makes the NVIDIA solution a smidgen more expensive, and we've seen from our initial look that X850 XT CrossFire appears to have better performance. This would make ATI the no-brainer.

Next generation: If you buy a dual graphics motherboard now, you can either buy 7800s now or wait for X1800s to see how they perform in comparison. We're not sure which is going to end up better, and we need to conduct further testing on the mainboards to establish definitively which 'platform' is faster. Stay tuned.

2. I have an ATI card on PCI Express already. Should I plump for CrossFire?

This is more interesting. We can assume you have a X800 of some description already, and you're plumping for the X800 Master card and a CrossFire mainboard, at a rough cost of (£150+100) £250 all in. For this, you'll get a swanky new motherboard with support for future ATI cards and extra graphics performance from the second board.

This does look tempting. However, there's something to be said for not throwing good money after bad. X800 and X850 cards don't support Shader Model 3.0, and unless you already have an XT, rather than XL, you're not going to have much fun with HDR in terms of performance. Why spend more money on what is, effectively, old technology?

If you really want to upgrade from a single card, buy a CrossFire board and get that performance gain, then wait for new cards.

3. How does the current CrossFire solution compare to a single NVIDIA 7800?

If you're buying CrossFire from scratch, it will cost you £500 today, as we established above. For £230 you can have a 7800 GT, and whack another £100 on for a new SLI board. We haven't published the numbers here, because it's kind of obvious - you can save £150 and have the same performance. 7800 is so blindingly fast, comparing it with an X850 is kind of embarrassing.

There's no doubt that CrossFire is a great technology. There's also no doubt that CrossFire motherboards are as good, if not better, as nForce 4 motherboards, and will make great gaming platforms. However, if you consider that a single X850 is £200, and a single 7800 GT is £230, you'd have to be bonkers not to buy the NVIDIA card. See this article for a rundown of 7800GT compared to X850.

4. How will next-generation CrossFire compare to 7800 SLI, and how does R520 affect me?

This leads us on to the last, and certainly most interesting question.

In less days than I can count on my hands and toes, R520, aka X1800, is going to arrive. It will sport full CrossFire support, Shader Model 3.0, and will be a hell of a lot faster than X850. It will match, if not exceed, the 7800 series for performance, and it is likely that the X1800 XL part will be pitched at 7800 GT price levels, making for an incredibly close contest.

We've mentioned that 7800 GT is a far better buy, at £230, than an X850, and so drawn the conclusion that buying X850 CrossFire is probably a little pointless. Well, the same holds true for X1800 XL. It will come in at around £250, and it will be a far better buy because it will offer so much more performance.

There's an argument, which you will see made all over the web today, for almost disregarding CrossFire on X800 series and just focusing on what it will offer compared to the 7800. The real question, then, is whether X1800 CrossFire is better than 7800 SLI. For that, my friends, we will have to wait just a wee while.