Yes I know this is old but, I do but hi folks and Dell made some tough iron, back in the day, to quote a guy that posted the DRAC recovery procedure on these :)) Somewhere… maybe on a Dell forum.
I was just scouting the webz for some spares, my r900 just died the other day. A psu blew and was shorting the other one too…
Probably an easy fix like a fet… or four.
Anyhow, I’m a bit curious about OP’s experience/result. Bought mine around 2014-2016, and I did it for pretty much the same reasons. Bought gpus for it a bit later.
It took a lot of hacking to get it working with only four modern gpus… Initial tests were done with just two old Quadro cards and got my hopes up. But it’s not easy.
Does not fit gpu cards without notching the pcie slots on the M/B and without converting the double-size cards to passive cooling, like removing shrouds, fans and maybe the 12v connectors. The slot spacing is 1.5 standard slots not 2! Using single-slot thin cards will make things easier.
The brackets need to be cut or removed and other means of securing the cards must be employed.
I’ve cut the lid and made a plastic extension to keep the airflow right and fit vertical 12v plugs. I might make it again from galvanised steel sheet… and rivet it. Maybe.
I took 12v directly from the PSU combiner board bus bars. Removed some insulation and bolted 2x2 12awg cables that went to a diy 12V PDU then a set of 12v atx cables about 6 inches long.
I jumpered the #present pin on every pcie slots used so the 16x cards would be seen in the 8x slots. Poked wires directly in the slot and routed around. (See pcie pinout)
More than 4 pcie gpu cards and none will be addressable correctly. Never tried dual gpu cards but it will probably act the same as there are not enough resources to handle so many devices on the pcie bus, even with all the pex chips in there. A modern video card is a complex device that is a compute node in itself with lots of extra stuff like hdmi audio, more than one video rendering block, etc.
None can actually drive a monitor. CRTCs are detected but require impossible window address space. We’re stuck to remote or the embedded 32 or 64mb ati chip with vga.
Today this machine remains more of a collection item with it’s four rx570 4g cards, 32gb or ram, just 16 slow cores and gets turned on just for a laugh or a hashcat/john grin
Pulls 500W idling, 1.3kw in full load. Can’t control the fans from userland so I just trigger the intrusion switch to get full speed cooling, needed when the gpus are at full load.
I had 64gbs of ram in 2bg sticks but downgraded to 4x8gbs to save power. (16w/stick)
These were never ment for mining or gpus. A lot of dremmeling and soldering and firmware fudging is needed. And a Perc battery will cost you a limb!
But if taken care of… will still boot after ww3.
And if anybody has ideas for hacking the address space issue I am still open, LOL!
I still have a wet dream with 7 water cooled cards in it :)))