3-4 Card setup Crossfire

[speedaemonz28]

Hey guys, for my birthday my wife bought me a 5850, Ive been running 2 4890s for a while and have been very happy with them. I tried out the 5850 alone but it couldnt perform near the 2x 4890s so Ive decided to put in some more 58xx cards..My board has 4 pci-e slots and Ive been considering the viable setup options.. My first choice was adding another 5850 or better yet a 5870....But.. I was thinking about it and think that the second, third, etc.. Cards really dont add all that much more to the performance levels (as opposed to your main card) so I was thinking for the price I could add two or three 5770s to augment the 5850 I have now and the level of performance wouldnt be that big comparitively.. Never done it though and Im sure some of you have, any ideas? Thanks!!

 

[Rustyy117]

Adding another 5850 will easily outpace 2x4890's so that would be the easiest option

adding a 5870 to your 5850 isn't a good idea as the 5870 will down clock itself to the 5850 levels, so you would effectively have CF 5850's but would have payed more than you needed too.

You can't add a 57xx series card to a 58xx series card so adding a 5770 to a 5850 is out of the question.

You can expect around 80% performance boost from adding a second 5850, but tri fire and quad fire doesnt scale as well and IMO wouldn't justify the cost.

2 x 5850's would be roughly 5970 performance in games that scale well with crossfire (most modern games scale well)

 

[speedaemonz28]

I thought the series requirement was in the 4xxx or 5xxx, not the say, 57xx and 58xx, glad to have asked. So if I get the 5870 and make it main, and then OC the 5850 up to its levels that wouldnt be viable? Dont think theres anything out there to justify 3 58xx at the moment, but would like to do the best I can with two for now.Thanks again!

 

[Rustyy117]

No you cant crossfire a 57xx series with a 58xx series

There are other differences with the 5870 compared to the 5850, like the 5870 has 1600 SP's and the 5850 only has 1440 SP's. I think the 5870 has 40 ROP's and the 5850 only has 32 ROP's, So there are some major differences.

Why not just get another 5850 and overclock both 5850's?

There's no point in buying a 5870 over a 5850 when crossfiring with another 5850.

 

[speedaemonz28]

Awesome, thanks for your help, I guess that also answers my future question of putting a 5970 with my 5850s..Looks like Ill be ending up with 4 5850s eventually..Now to go find a benchmark of 2-4 5850s to see what ill end up with.

 

[shadow187]

I'd just overclock both HD5850s to a 925core/1225mem and crossfire them. Performance at that level will be to the extreme, and you can always add another one later.

 

[speedaemonz28]

Will I need special cooling for 925/1225? my 4890s had such major heat issues in CF that I could never OC them and stay stable. Ive got liquid on my CPU which has succesfully gotten me to 4 Ghz (955BE) havent looked into gpu liquid stuff though.

 

[obsidian86]

compare 4890 power draw with a 5850 less

watts mean less heat

 

[speedaemonz28]

heh, nice.. guess thatll help a bit.

 

[Rustyy117]

I've got my 5850 under water and its great for overclocking, But the stock cooler is also pretty good and fairly quiet too.

 

[speedaemonz28]

Best answer selected by speedaemonz28.