[Solved] 4870x2 2GB + 4870 512mb in crossfire

Forum Graphics & Displays : Graphics Cards [Solved] 4870x2 2GB + 4870 512mb in crossfire

Hi, I just bought a Diamond 4870 512mb for $55 shipped from NewEgg after I checked Tom's Charts and found that two 4870 512's in crossfire beat out my non-reference 5850 in Bad Company 2 and BF3 at 1920x1200. But I bought the last 4870 512 on sale and obviously crossfire was my intention. I am looking on eBay and see some 4870x2's available but they have 2 Gb or 1Gb for each GPU. My question is ... by running the 4870x2 in crossfire with a 4870 512 will it drop the 4870x2 down to 512x2?

Either way it should still wipe the floor with my 5850 seeing how just two 4870 512's beat it. But my question is about losing half the Vram on the 4870x2. I'll probably pick up a 4870 1gb for tri crossfire and get another 4870 512 to sell in a crossfire machine to build after I sell this Phenom II x2 with the 5850.

My setup:
q8300 @ 3ghz
Asus P5Q Pro Turbo Green
2x2gb KHX T1 DDR2 1066 @ cas 5 with another set on the way.
1x 64 Gb Adata SSD
CoolerMaster GX750 with 60 amps on 12v alone

I checked power consumption and it looks like I would have just enough to run even 2 4870x2's but obviously i'm only running the one with a 4870 so I should be perfectly fine.

Reply to drewnashty

Best answer

Yes you would be stuck at 512mb vram. The way crossfire works is that it loads the same data into all 3 cards and renders the game spreading out the workload.

Message quoted 1 times

Reply to holdingholder

Also even if you buy a 1 GB it to will run in 512MB. Unless you are going to run above 1920 x 1200 in resolution. Then you don't need the 2 GB of Vram.

Message quoted 1 times

Reply to DM186

holdingholder wrote :

Yes you would be stuck at 512mb vram. The way crossfire works is that it loads the same data into all 3 cards and renders the game spreading out the workload.

Cool that's what I figured I just wasn't sure*, thx.

DM186 wrote :

Also even if you buy a 1 GB it to will run in 512MB. Unless you are going to run above 1920 x 1200 in resolution. Then you don't need the 2 GB of Vram.

Sorry for the confusion, what I meant was when I buy the 1Gb, pull out the 512 card and replace it with the 1GB so I would have the 4870x2 2GB and a 4870 1GB in tri crossfire. That way I won't be disabling any of the VRAM and essentially as I have confirmed now with you guys running 1GB per GPU.

I would then use the 4870 512mb for another build.

My Asus board only has two PCI Express x16 slots so I can't run three separate cards.

Thx for the replies. Enjoy your holidays!

Message edited by drewnashty on 12-16-2011 at 02:15:54 AM

Reply to drewnashty