I just got two used ATI OEM 5970 from eBay, the seller says they were bought together in a Dell Aurora system. They are the ones that have the metal handle on rear of the backplate.
In short, one of them doesn't boot at all, no BIOS screen nor anything, the other shows 3 cores!! in BAMT (atitweak). The seller claims that the non-working one is configured as 'slave' in CrossFire so I need to start them in CF configuration with both cards in 16x pci-e slots to make them both work.
Is this a plausible story? If so, will it be enough to find a computer with 2x pciEx16 CF mobo and disable CF on the secondary card - so it can work solo?
The thing is that I have a rig with watercooled Sapphire 5970, CoolerMaster RealPower Pro 850 (750W at 12V) and nothing much more except i5 on asus P7P55D-E LX motherboard, and usb stick with BAMT. The problem is that the MB has only one 16x pci-e slot. But I had tried many Radeon 5xxx and 6xxx with the extender in pci-e 1x slots and they all worked no problem - including two Sapphire 5970 and that before-mentioned 3 core ATI OEM 5970. So it is a problem for me to find a proper high-perf CF enabled mobo - and would prefer a solution without it.
Little more details:
I tried putting both cards as secondary, connected to pci-e 1x->16x extender, and with Chieftec 1000W PSU, just to be on the safe side. The 3-core card works and mines normally in BAMT, boots in Windows and I can see one core (no CF cable) or 2 cores (with CF cable). In BAMT aticonfig shows 2 cores on new card, atitweak shows 3 cores, the same as modified radeonvolt.
With problematic card BAMT boots, but can not start Xserver - aticonfig shows 2 cores, atitweak can't work without X, modified radeonvolt shows only 1 core. Windows hangs at logo screen. It can boot into the safe mode and shows 2 cores with CF cable connected.
Both cards have the same BIOS: (and on both cores they have master BIOS, if that might be the problem)
GPU Device Id: 0x1002 0x689C
HEMLOCK MASTER XT BIOS Rev B UCODEv:1195
(C) 1988-2005, ATI Technologies Inc.
I would prefer not to change BIOS if possible, as the seller claims he didn't touch it - and I don't want to get into dispute about that if I decide to return them.