Crossfire Help ...

[alien.46.uk]

Hi All ...

I was looking at the Saphire 4870 1Gb Card in my build (and no, if anyone remembers my first thread from some time ago, i still havent decided ) ...

But anyway, I'm now looking at the possibly of 2x XFX 4830's instead, both for the slight increase in performance based on current reviews and opinions (20-30%) but also because I've never had an SLi or CFx set-up and just really want to try one.

However, most boards both Intel and AMD side from P35/P45 to 770/790GX all run CFx @ 8x/8x and some even @ 16x/4x ...

Would this set-up see noticeable reductions in performance over say X38/X48 or 790FX which run them at 16x/16x ...?

Main reason is cost, most boards that run @ 16x cost around £150 minimum, where I could get a nice P45 or 790GX board for around £80-£100 etc ...

Any help appreciated on this matter and maybe i will finally decide on a build.

Thanks in advance.

 

[Guardsmon]

um I'm pretty sure a 4870 1GB would be better than 4830's in CF any how. Yeh I know it spoils you're idea of having a CF setup, but if it doesn't give performance increase, why bother?

 

[LeJosh]

Just get the 4870 then in the future you can fire another in.

Edit - It's going to save you a lot of headaches with the one 4870, many crossfire related problems arise in games and have to figure ways around it.

 

[reflux]

P45 might run 8x 8x, but that's PCI-E 2.0, so the bandwidth is effectively double PCI-E 1.0, 8x 8x, and is perfectly suitable for running CrossFire.

P35 @ 16x 4x meanwhile is a waste of time as the 4x slot cripples the card.

 

[alien.46.uk]

@ Guardsmon: There's several reports of CF 4830's beating the 1Gb 4870 (both set-ups fully stock clocks) ... Even reports of them beating the odd GTX280.

@ LeJosh: If I did that I'd probably never bother putting in a second, just keep changing the single as things progress lol ... Hence why I want to try now.

@ Reflux: Yeh I agree the 16x/4x is pointless, but don't X38/X48 and 790FX also all run at PCI-E 2.0 both at 16x/16x? Would that not also theoretically mean an increase over PCI-E 2.0 8x/8x P45?

 

[reflux]

@ Reflux: Yeh I agree the 16x/4x is pointless, but don't X38/X48 and 790FX also all run at PCI-E 2.0 both at 16x/16x? Would that not also theoretically mean an increase over PCI-E 2.0 8x/8x P45?

Aye, it does, but the bandwidth increase is only worthwhile with the really fast, £300+ cards. With a couple of 4830s, you ain't gonna notice it.

 

[steve258]

Until very recently I had 2 HIS 4830 in crossfire setup, and it wasn't until one of them broke and I switched to a 9800GX2 that I realised just how good that setup was. 8x PCI-E 2.0 wasn't an issue at all on my P5Q, there is a review somewhere that compares xfire on P45 against X48, and the difference is only noticeable at high resolutions which I doubt the 4830 can handle anyway even in crossfire.

I had xfire problem with fallout 3 which I had to rename to oblivion.exe to get crossfire support (there's an app called ati crossfire extension which will force xfire on as well). And I noticed poor performance in cryostasis (expected without physx support) and GTA IV (console port plus limited by dual core).

If you just want to try xfire for the first time then go for it. But for me the novelty wore off pretty quickly and I soon found myself trying on different drivers and dealing with the little issues like BSOD on desktop (think it was related to dual monitor output on xfire) and the "driver stopped responding" message, which often resulted in screen blinking that eventually led to BSOD.

 

[Guardsmon]

alien - if you want to go try it feel free. I don't hold you're bank card. We're all just giving you our 2 cents. Mine is that although some benchmarks say 2x4830's are better, I'd go with the single card. You don't get any compatibility issues that some games have, you have room for expansion in the future if you want. It's easier to setup and cheaper.

Buy as I said. It's totally up to you. Good luck with whatever you decide.