5850 CF or 5870+5850 CF??

[dmcfc]

I'm thinking about going crossfire at this point as I'm probably going to go eyefinity sometime soon.
My question is, there is a Shell Shocker deal going on on newegg right now that is selling a 5870 2g eyefinity 6 for $179.99 (after rebate) + free shipping and the cheapest 5850 1gb is for 176.99 + 4.99 for shipping = 181.98.

I know that 5850+5870 is actually worse than 5850 CF by usually around 2fps but as this 5870 I mentioned has 2gb would that make any difference in performance going crossfire and eyefinity? 5870 2gb + 5850 1gb or 5850 CF?

(I already have a 5850.)

I need an answer as soon as possible as it's a shell shocker limited time deal.

I'm pretty sure it can handle it, but just to make sure, can my Antec Earthwatts EA750 handle this setup??

Thank you!

 

[iceclock]

if u pair up a 5850 and a 5870 the 5870 will downclock it performance , to the 5850s speed, so honestly id pair up a 5850 with a 5850, but its up to u , id recommand u buy another 5850, to be in sync with ur other one, but it comes down to ur choice

 

[dmcfc]

Would it make any difference in performance in eyefinity though? or would it also be the same performance as the 5850 CF in eyefinity?

 

[iceclock]

im not shur honestly, but it ur 5870s gonna downclock itself, whynot just get another 5850 and not give urself a head ache, if it was me id get the same card to run in crossfire,

it doesnt seem logical to get a 5870 to just have it downclock its performance to the 5850s specific clockspeed and avaible bandwith

 

[dmcfc]

yeah, just thinking about getting the 5870 cauz it has 2gbs, but if that doesnt make any difference as my 5850 is 1gb I'll probably go with another 5850. Well and also cauz of its looks, haha, i like the look of the reference card more, and the 5870 has the reference cooler which would look better with my reference 5850.
Thanks for the fast replies iceclock!

 

[iceclock]

no problem dude anytime

 

[Dougx1317]

If you have a 5850 1GB, get another 5850 1GB. The extra power and RAM of a 5870 2GB would be wasted if it was crossfired with a 5850 1GB. The 5870 2GB would only have the power and RAM of a 5850 1GB. This includes if it is being used for eyefinity.

 

[vvhocare5]

I would like to see some of the sources for these positions being stated. I may be wrong, but I am not aware of the 5870 "downclocking" itself.

What happens is each card draws the appropriate frame at its clock rate. With a 5850 and a 5870 you will see slightly better frame rate as 2x5850's. When its not crossfired, you get the better performance of the 5870.

Looks llike a winner to me....

 

[iceclock]

no u dont, when u crossfire 1 stronger card and one slower card, the faster one will sync its speed with the specifications and allocated bandwit of the slower one, no point of pairing a faster and one slower card if it comes to the same of having 2x5850 or 1x5870+5850 and have the same results,

 

[dmcfc]

Best answer selected by dmcfc.