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Replying to:
skylarking
3 Zinc

Re: Disabling onboard video and upgrading video card on Dell PowerEdge 1950 server

Atmuris, that link you referenced modifies a motherboard x8 PCIe slot making it mechanically open ended thus allowing a 'higher lane count' card to be inserted into a 'lower lane count' slot. It does not convert a x8 card and magically make it x16 Smiley Happy.

Do note that the PCIe spec allows a lower lane count card to fit in higher lane count slot without issue, that is ,as an example, an 8x card can be placed into a 16x slot. However, the reverse is not true as the spec does not support it.

Fortunately, the PCIe spec is rather robust and allows cards to negotiate their lane use and power needs at start-up Smiley Happy  thus a simple hack is usually enough to get a modded x16 graphics card to work in a x8 slot (on a server motherboard). I say usually since graphics card manufacturers do not always design in a way that allows this as it's not in the spec and so they don't bother.

The mod is simple enough and involves using a fine tooth hacksaw blade to cut away side contacts 50, 51 & 52 from the graphics card connector itself, thus effectively creating a cutout/key (that mimics the manufactured cutout/key between pins 11 and 12) and allows the card to be inserted into an 8x slot (of in my case my PE T610). No mods were needed on the server motherboard. Obviously the rear of the card hangs out past the connector so i insulated it with gaffa tape prior to insertion as a precaution. The card was tested in two different slots and auto negotiated using the full 8 lanes in the x8/8 (x8 mechanical x8 electrical) slot and the full 4 lanes in the x8/4 slot while consuming 32W max (which is greater than the 25W max per slot recommended by Dell but this is based on cooling issues so it will not cause problems unless i fill up all the other slots).

Do note that not all motherboards and graphics card combos will work without a hardwire of the PCIe "presence detect logic". For an x8 slot, this means connecting/soldering a wire between pin A1 and B48 either on the PCIe connector or on the graphics card itself. In my case this was not needed on the T610 PCIe slot or XFX GF7600 GS graphics card Smiley Happy

The risk with cutting the slot on the graphics card is that the circuit board tracks may be close to the tops of the printed pins and unseen (since they are multilayer boards) but at $40 for an old DX9 capable graphics card, it was cheaper that an wear extender without the hassles that these bring by raising the card in the chassis.

Once the graphics card was plugged in, the 'disable on-board graphics' option was accessible in PE T610 BIOS so on-board graphics was disabled and the monitor connected to the new graphics card. Now i have my monitor running at its native 2550x1440 resolution Smiley Happy

Some basic info on PCIe can be found at http://www.pcisig.com/developers/main/training_materials/
PCIe pinouts can be found at http://pinouts.ru/Slots/pci_express_pinout.shtml
Another PCIe x16 to x1 video card conversion at http://www.invisiblerobot.com/pcie_x1/

From these resources, you should have a better idea of what to do, though no guarantees can be given.

Lastly, NVIDIA and ATI licensing requirements has made it rather difficult to use multiple graphics cards on non certified motherboards! Not impossible but difficult (and it's on my todo list).

Oh, and if the BIOS does not allow for disabling your on-board graphics function, other issues may occur which could be challenging to fully resolve.