What P55 board for Crossfire with two 16x lanes?

sastusbulbas · 12 Oct 2009 at 21:09

As above,

What P55 motherboards are recommended for running crossfire with two 4870 cards running at a full 16x each?

Pete.Dakota · 12 Oct 2009 at 21:27

None, ASFAIK. They scale down to 8x with two cards.

sastusbulbas · 12 Oct 2009 at 21:31

So the only way to get the most out of two 4870's would be with the Intel 920 platform?

Franksi · 12 Oct 2009 at 21:39

P55/i5 does not provide enough PCIe lanes in total to be able to run x16/x16 for a Crossfire or SLI setup. If you are set on going SLI go for X58/i7

McstylisT · 12 Oct 2009 at 22:23

sastusbulbas said:
So the only way to get the most out of two 4870's would be with the Intel 920 platform?

Yes , as mentioned by others that is the only way at present.

McT

blaineoliver · 12 Oct 2009 at 22:45

Or amd setup, 2x 16 on amd.

the1gooner · 12 Oct 2009 at 23:38

sastusbulbas said:
So the only way to get the most out of two 4870's would be with the Intel 920 platform?

Two x16 lanes wouldnt be needed with 4870's in crossfire.

I personally would rather have a single 5850 or 5870 than messing about with crossfiring 2 4870's.

MagicBoy · 12 Oct 2009 at 23:49

It's PCIe v2, so it's less a problem than it was with Crossfire on PCIe v1 as each lane is twice as fast.

the1gooner · 12 Oct 2009 at 23:54

MagicBoy said:
It's PCIe v2, so it's less a problem than it was with Crossfire on PCIe v1 as each lane is twice as fast.

Yep, the difference when crossfiring 2 x 5870's between x8x8 & x16x16 is something like 2-3%. Hardly worth worrying about.

sastusbulbas · 13 Oct 2009 at 01:25

I have the Sapphire ATI Radeon HD 4870 1024MB GDDR5 Toxic Edition PCI-Express Graphics Card at the moment.

If Crossfire brings benefits with two of these cards I may be interested in a second, as it will only cost me £135 which is less than the new tech.

But as I am still deciding on a build, well I guess I would like to factor Crossfire in.

So would i5 with a MSI P55 GD65 be just as good as a i920 with a suitable sub £150 X58 motherboard if I wanted to get the best performance out of Crossfire with two 4780's? Or would I be better of just sticking with an i5 build and later upgrading to a single better card?

Is the 16x/16x issue likely to become more of an issue with future games or is it just a benchmark point scorer?

Chong Warrior · 13 Oct 2009 at 13:38

The smart money would go on an i5 system with a single 5850

pcredstar · 13 Oct 2009 at 19:33

I too had this decision to make and decided just to go for a p55 with an x8/x8 setup. I'm doing this to crossfire a 5850 in the future. Performance loss over x16/x16 is only a few fps.