I was wondering if anyone knew if there is an advantage or disadvantage of using 1 - 1GB video card vs 2 - 512MB video cards running in crossfire.
You're making a very common mistake (thanks to marketing) in your evaluation of video card capabilities: the amount of memory has NOTHING to do with the speed of the card. Memory is important when it comes to the amount of memory available to load textures and other graphic buffers in to. It's always better to have more memory, but at a certain point you'll go past a limit that will make a difference for the card. For example, a Voodoo3 with 1gb of memory (which, of course, doesn't exist) would have been no faster than a Voodoo3 with 16mb of memory because the card just wouldn't have been fast enough to make use of it (nor would games of that era have utilized that much memory).
Now, today, if you're going to be gaming at high resolutions (meaning anything 1680x1050/1600x1200 or higher) and playing newer games you're not going to want less than 1gb of memory on your card, simply because the cards today are fast enough to take advantage of it and modern texture size needs it, especially if you're using anti-aliasing, because if you have enough free memory bandwidth anti-aliasing will literally provide no performance hit.
There is an exception here, though: if you can run two of the same card with 512mb of memory in crossfire it has the potential, IF the game you're playing takes advantage of it, to be double the performance of a single card on its own. This is because it is simply two equal cards sharing the load of the work. The disadvantage here is that, when running in crossfire or SLI, you can only take advantage of the amount of memory on a single card, not both together like you would think, so memory limiting can be an issue. For example, my 4850x2 is marketed as being a 2gb card, but it is really two 1gb cards operating together, which is NOT the same thing. Each card has its own 1gb of memory to utilize, NOT a combined pool of 2gb. However, typically the sheer speed of the two cards together will overcome this memory limit and still be much faster than just using a single card with twice the memory.
This is why my 4850x2, which only has GDDR3 memory, greatly outperforms a single 4870, which has GDDR5 memory, in games that utilize crossfire.
So what it comes down to, is that if you have the budget, and need for speed, of two cards, that will always be the better option (unless you're choosing between two 4670s or a single 5890, but that's an extreme example). But if you don't have the budget for two cards and must only get one, absolutely be sure to get the 1gb option. It WILL make a difference when you can't rely on the speed of two cards operating together to overcome the limitation.
Hope this helps!
Home
Help
Search
Login
Register
Send this topic
Print
Topic: 2 video cards vs 1 (Read 1649 times)
