Crossfire Build

[maxzuk]

Hi hope you can answer a few questions.

Currently own a MSI 6970 lightning core 940 & Would like to add a MSI 6970 core 880

Questions are
I have to down clock my card to 930 for BF3 anyway so would be looking at over clocking the core on the 880 and down clocking the 940 hopefully getting around the 900 mark, is this OK

My PCI express slots only 1 is 16x other is I think 4x have been told that it wont make much difference is this true

Last question power, am aware that the lightning uses 2 8x power supply and the standard uses 1 8x and 1 6x and have sourced leads to deal with this my question is will my XFX pro 750 power supply be enough to run this have used an online calculator to check but would like confirmation.

power supply runs an

above card
i7 processor
2x hd
1x dvd
1x ssd
16 gig mem
H80 cooling

Thanks for any replies

Nigel

PS If all ok never done the crossfire thing so any help on software and or just general tips greatly appreciated

 

[maxzuk]

Sorry to bump but moving down list pretty fast

Anyone?

Thanks Nigel

 

[Rusty0611]

Hi there

It's never recommendable to run crossfire on a 16x/4x. You will lose some performance (compared to say 8x/8x) but the main issue is that people report more microstutter in this configuration.

If you do proceed then 750W would be enough but you are going to be around the limit. It should be OK. But if you're considering getting a new PSU to be sure then it just isn't worth it due to point made regarding 16x/4x.

 

[Surveyor]

Your 750W PSU should be enough but with the Lightning and the MSI 6970 (Twin Frozr III I assume) you'll need four 8 pin PCI-E power connectors.

Does the PSU have those?

CrossFire at x16/x4: Does CrossFire Work At x16/x4?

That's with 6950's.

Maybe 6970's would be slightly more bottlenecked.

 

[maxzuk]

Thanks guys

 

[maxzuk]

Only prob I have now is sata cables in way does anyone knoe of a sata cable with a l bend on head that instead of going down goes right?