hello.. few minutes ago, i've searched in google and come out for several forums.. (but, other forums are a bit messy and guru3D is the best.. i googled about the 4870X2 to crossfire with the 4890.. and then, a guy said that crossfire doesnot downclock your card to the lowest speed but it is only the SLI which do that..is this for real? because, i'm planning to buy a 4890 to crossfire with my 4870X2.. p.s.- postes a thread before about crosfire 4890 with 4870X2 but the title is not catchy enough and end up to be unsolved. :wanker:
Well yes and no, I think you've misunderstood. No, crossfireX doesn't -literally- downclock your card to match the other one. However, the 4890 will perform exactly like another 4870, so you might as well downclock your card, to save on heat and power.
Yes, but that's a tall order without good cooling as you'll see. Once you get two video cards in the same case, things heat up big time.
Lutfi if I remember correctly u hav ur trifan 4870x2 overclocked vey high already, about 830 core? U said u were running the card at 100% fan, I wouldn't keep it there and trifire, because I think u would still have heat issues if u introduce another card into the case, btw did u buy that bigger monitor yet?
@larwain how about crossfiring hd4890 with hd4670 for example. Is it possible? Will it downclock hd4890 and lock it SP so it'll match hd4670? I thought the idea of crossfireX was combining any of HD4xxx...
I don't even know if that's possile; different clock and mem speeds, different SPs, different bus size(256 vs 128 bit)and also DDR5 vs DDR3, good luck getting that to work. Even if it did would be a waste as it would perform like 2x4670s
So how about hybrid crossfireX ? Still u think it doesn't enhance the system? as far as i know it works like this: igp is main gpu connected to the monitor and card in pci-e is second card used only to powerup igp when it lacks performance in 3d mode/video encoding. It still is based on crossfireX i think. Tell me if i'm wrong EDIT: check this - its official Code: http://game.amd.com/us-en/content/images/crossfirex/CF_combo_chart.jpg
jaeso: i'm still seraching the shop that sell the monitor.. and still not buying.. because not enough money yet.. yeah.. i overclock my 4870X2 to 865MHz (core) & 1050MHZ (memory)...
That overclock would almost certainly fail with another video card in the case. No, it won't work. Hybrid crossfire X works fine and I know what it is, but your link doesn't seem to mention it. Either way, I don't think a 4670 is compatible with that either. Would be much better to crossfire a 4670 with a 4670, if you wanted to do that. Would be much better than that to simply buy a 4870, it would be cheaper.