Possible to add memory to 4850? Or run a 512MB with 1GB in Xfire?

well unfortunately, there is no way, that i know of at least to increase the memory, maybe there is some crazy mod out there. As for running in crossfire, you can use a 1gb card to crossfire it but it can only use up to 512 mb of memory on it.

In crossfire or sli both cards have the exact same date, in both cards memory, so the 1gb will only be able to use the 512mb.

So if you'd want to increase your memory, you'd have to buy a new card

I was afraid of that!

So, let's say I bought a 1gb 4850, would it be better to run it alone (sell the old one) to take advantage of the extra memory, or in crossfire for the extra processing power?

Doesn't matter too much, but I just realized that I have a 4870, not a 4850

You are MUCH better off running it at CrossFire than getting a 1GB card and using just that. Realize, the RAM DOSE NOT get added EVEN in CrossFire. Each card is STILL limited to 512MB.

That's the thing, in games like GTAIV it seems that 512 of video memory hold you back from better textures, so even in crossfire with my current card, I'm still held back in that way despite the extra grunt.

Yes ultimately it'll hold you back, at higher resolutions and more detail, the gpu core can still do the work,

unfortunately once you run of vram, it moves to system memory, which is several times slower, so if your running a pretty high resolution monitor, you may want to eventually invest in a 1gb or higher card, but i wouldn't do that unless you go to at least 5850 so at least you already see an increase in performance, if you go with something like the 1gb version of the 4870 you'll see additional detail/performance in a few titles

The vram doesn't add together but only mirror, this is due to DirectX and the need to share texture data. The old 3DFX did have vram doubling but not in full. So your best choice is get another 4850 512mb edition and forget about any thing else or purchase something much better like a 5830 or a 5850 but that is up to you to decide.

Can I crossfire a 4850 and a 4870?

I think so, I have seen hybrid crossfire systems before I and may build one my self. Its worth a shot.

I believe any 48xx series card can crossfire with any other 48xx card, obviously the results won't be as good as two of the same cards