5850 Crossfire on a P7P55D Mobo help

[Justmotley]

Hi everyone, I have a question that I hope you will be able to answer for me.

I recently upgraded my system (i5 750 @4ghz, 4gb ram, Sapphire 5850, P7P55D mobo) and have been really happy with it. I got home today to find another 5850 on my desk from my other half as an early christmas present , but this motherboard is only x16 x4 PCIe.

I was wondering if I was to Xfire these cards would i still get an increase in performance or would i be better to stick with one card (or sell em and get a 5870, or even get a new Mobo already and sell the old one?). I really dont know what to do and would appreciate your advice.

Many thanks

 

[Ast3r]

Sell the mobo add a couple more quid and get another mobo.This would do you fine.http://www.overclockers.co.uk/showproduct.php?prodid=MB-206-GI&groupid=701&catid=5&subcat=1495You're so lucky I wish my gf would give me something like that for christmas....well still have hopes I will give her hints as to what I would want as a gift

 

[psychas]

sell mobo buy new one.

but i thought all 1156 mobos have x8x8 when crossfired or this is exception? ^^

 

[Justmotley]

I should have thought about it when i bought the mobo but oh well. Sounds like the easiest option. Will order the new one tonight and get on ebay for the old one. Thanks

 

[CitizenX]

Dont bother selling it... it will make very little difference

clicky

 

[Ast3r]

But his mobo won't do xfire x8-x8 it will be x8-x4 or x16-x4.

 

[CitizenX]

But his mobo won't do xfire x8-x8 it will be x8-x4 or x16-x4.

I will return to hole from where I came from...

 

[Ast3r]

Sorry didn't quite get that So that means that the performance he'll get from xfire 2xHD5850 at x8-x8 be almost the same as 1xHD5850 at x16?

 

[psychas]

Sorry didn't quite get that So that means that the performance he'll get from xfire 2xHD5850 at x8-x8 be almost the same as 1xHD5850 at x16?

no he will get same performance as two 5850 on x16

 

[CitizenX]

Sorry I thougth I was wrong... but looking at the Motherboard, I would think he would get x8 x8 from it.

If you read the article I attached, it says that the performance drop off for x8 x8 vs x16 x16 isnt exactly much - 5% or less.

Unless that money is burning a hole in his pocket I would stick with what he has.

 

[Justmotley]

So would you guys agree that the Gigabyte mobo suggested is the one to go for? What speeds will that give me 16x 16x or 8x 8x?

 

[CitizenX]

So would you guys agree that the Gigabyte mobo suggested is the one to go for? What speeds will that give me 16x 16x or 8x 8x?

You need X58 Chipset Mother board, which doesnt support your i5 CPU. So its both MB and CPU time if you want x16 x16.

Why not OC the cards in your existing rig and see what they do... they should rock and roll.

 

[Justmotley]

Hmm i guess I could - i just dont want to hideously bottleneck myself because of a mobo. Thanks for all your suggestions.

 

[muppetkiller]

I would try it out my self first before u move on the MB. Do some benchmarking and see what other people get with the same set up but on I7 MB's.