Vista - who's running 2 4870x2 in crossfire

I glossed over that part, lol

Did /does Vista x64 report all 8GB in use? ie do you have the memory remap feature enabled in BIOS.

Did you try Stoneys suggestion of uninstalling the drivers, booting into safe mode, running driver sweeper as admin and then booting normally and then re-installing the drivers?

It may also be worthwhile installing the drivers with only one card installed and then physically adding the second card if the driver installation worked with the individual card.

Yeah, I thought so. Sorry.

I've seen where people had to install drivers twice for crossfire setups so your last point sounds good, though I'm not sure if it's neccessary to have the other card removed. Definitely worth a try though.

With my 4850's I never had to, but when I put the pair of 4890's in, I had a hell of a time getting them to play nice. Removing one GPU, installing the drivers first and then adding the second GPU finally did the trick

It's more of a last ditch resort.

Just to sum up a little bit the series of posts under this thread. Who is running 2 Radeon 4870x2 in Crossfire under Vista x64?

I tried that configuration but I got problems while installing the latest drivers + CCC. Every time I tried to run 3D apps the PC crashes.

I'm now trying with Vista Ultimate 32 (x86) and off course I had to remove 4GB of RAM as Vista 32 won't recognize the original 8GBs.

My conclusion is that ATI drivers suck under 64 bits Vista-based systems. Hopefully, before the end of the world ATI developers will manage to provide good drivers for crossfire in 64 bits systems. What a pitty is to have 4 GPUs and not being able to use them with lots of RAM for apps.

cheers and happy moon landing everyone!!

I forgot to mention (after reading the latest posts) that I connected both cards using modular cables. I didn't want to try the hardwired ones. Besides, as someone has already said in a previous post I don't think this is a problem of PSU as I'm running both cards in crossfire in Vista Ultimate 32 now. I've tried Crysis at full capacity and after a while it crashed, though crashes are typically common in ANY apps. I will however try the game again just to be sure the crash is isolated and off course I will try other games as well. This suggest that IT IS NOT a hardware problem but CLEARLY a software problem, more specifically BAD drivers from ATI for 64 bits systems.
I tried installing the drivers with only 1 card installed then installed the second card and enable crossfire and the problems still persisted. 3D apps hang up the PC under 64bits.

smarteyeball, you have the same PSU. One question i have regarding the PSU is what does the 12v1 and 12v2 label on the blue outlets mean? When you say V1 rail, what exactly are you referring to? is V1 rail = 12v1 and V2 rail = 12v2?

I have 1 card connected to the pair of 12v1 sockets and the other card to the pair of 12v2 sockects (i thought, 12v1 for one card and 12v2 for the other card). Is that ok? I mean, I don't seem to have power problems but I want to be sure I understand the terminology and the way to connect the cards.

Thxs

This may not be much help. I run 2 separate 3870X2's and everything but the fan speeds work just fine. My system runs just a bit hotter from the two GPU's. But it is OK. The toys we have sure are fun at times!

Yep

That's fine how you have it, since you aren't 'mixing the rails' ie one plug from 12v1 and one plug from 12v2 into one card.

However Corsair do recommend using the two hardwired plugs for card A and the blue modular into 12v1 for card B.

This is from the Corsair support forums:

You do have only one Crossfire cable attached between the cards? (the tab closest to the rear of the case)

This is from the Corsair support forums:
You do have only one Crossfire cable attached between the cards? (the tab closest to the rear of the case)

[/QUOTE]

I will change the connection today. I will use the fixed PCIE cables for the first card and a pair of modular cables from 12V1 for the second. Although it is good to follow these recommendations I don't think that will make much of a difference as both cards seem to be working just fine at the moment under Vista Ultimate 32. I need to keep testing though. I'm planning to install Vista Ultimate 64 this weekend and try a couple of things I've been reading in forums like e.g. BIOS settings (init display set to PEG), only 4GB of RAM rather than 8GB (boy VU 64 will suck with only 4GB), installing only 1 card + drivers and then installing the second card (although I've tried that already). I will post the results.

Btw, my cards have only 1 CF bridge connector each so I have no way to screw up the connectivity between both cards.

So far I tried Crysis with everything set to very high and the game run well for a while then it crashes. This may be just a glitch..you know...this is the common aspect of every game, sometimes they do crash, but it may also be that I need to install the hotfix/patch release by ATI.

I'll keep you all posted.

thanks for the help!!

guys, I have the same cards cross linked, they run fine after I tweaked the system. I'm curious about the way your monitors are set up? Are you running several monitors are a single monitor? What type of cable are you using if you use both cards on one monitor. right now I am using one output off of one card but they are crossfired linked.

Two monitors. One 24" DVI and one LCD projector DVI>VGA adapter both connected to one card.

In single monitor mode, it's just the DVI connected monitor.