Dell PowerEdge 2950 offers a lot of power, but is severly limited in its graphics capabilities. I recently bought a second hand one quite cheaply to use as my main PC, but then spent a long time trawling through Google search results to find out if it was possible to upgrade the graphics adapter. The impression I got was that one or two people had had some success without needing to do anything, whereas if it didnt work first time it didnt seem possible to do it. I hope this post is of use to all those that couldn't get it to work.
For the record, the model I have is a 3rd generation 2950, denoted by a white III in a circle on the front top left hand size of the chassis.
I decided to upgrade to a video card that someone on the Dell forum said that they had once used, and that a couple of other sites were selling as 'guaranteed compatible' (obviously I didn't really believe they were telling the truth). The card I bought was an Asus ATI Radeon HD6450 1GB Low Profile PCI-E. It is a low-end card which I chose because it seemed like the most likely thing to work. I have absolutely no idea what others will work, as I was unable to find an official compatibility list from Dell.
The first issue with this card is that it is PCI-E x16, whereas the standard PCI-E riser card in the 2950 is x8 - so it wont fit. Fortunately it is possible to run a x16 card in an x8 slot, but with severely reduced bandwidth (so we are further reducing the bandwidth of this low end card). As it wont fit, we need to make it fit. There are two options here, firstly you could remove the extra pins from the graphics card with a demel. This option is valid (it sounds like a joke, but its not), but is irreversible and means you can't take it back to the shop if you cant get it working. Instead I opted for the second option, which is to cut the back out of the connector on the riser card. This results in unconnected pins overhanging the card, which is OK.
The following image shows the riser card that I'm going to put the video card into.
The next image shows the PCI-E x8 slot with the back carefully removed.
Finally here is what the riser card will look like with the graphics card installed. Notice how the second half of the pins hang over the edge & are not connected. This will reduce the performance of the card.
Once that is back together, there is one other thing that I needed to do. It appears that the Dell Remote Access Card (DRAC-5) on my machine is incompatible with video cards other than the built-in one. This might be because they share the PCI-E bus or something. I have no need for DRAC, so simply unplugged it, as can be seen in the image below.
So thats it. Put the lid back on the case an fire it up. In the next picture, the CRT screen is plugged into the ATI Radeon cards VGA output, and the LCD in the HDMI. Nothing is connected to the integrated VGA port. The Windows 7 'Windows Experience Index' base score for this graphics card is 4.4 plenty for my use.