I have a *reasonably* powerful desktop that I use as a dev machine, and now that Steam for Linux is starting to "build up steam" (terrible I know) I've been thinking of replacing my low end video card (and also get a dedicated sound card) so I can play some games on my rig as well.
Does anyone have any recommendations for either?
My current build has:
Intel Core i7-920 2.66Ghz 8M LGA1366 CPU
Asus P6T Intel X58 Socket LGA1366 Motherboard
12 Gig Corsair Core i7 XMS3 12GB PC12800 DDR3
Ubuntu 12.04 64 bit (and I tend to upgrade about 5 months behind canonicals release schedule, so my system will always be reasonably up to date.)
Well Nvidia linux drivers are kinda awful, well so are AMD's but they're at least workable from my experiance. So depending on your budget pick up anything between a 7770-7970. 920's are still great CPU's and everything else in your rig should be alright.
The AMD driver situation is... odd, to say the least. There is the free and open source driver, which is installed by default if you have an AMD card, and is also at least partially developed by some folks at AMD, then there is the Catalyst proprietary driver, which is closed source. The free driver works very well with the linux environment, is "perfectly" stable and works right out of the box, but isn't very good at 3D things, i.e. what you bought the card for. The proprietary driver is somehow more pathetic, in that while it will run the crap out of Minecraft (the only 3D game I've run on linux thus far) even faster than on Windows, it literally cannot play a simple video at an acceptable framerate. Neither could you smoothly drag a window across the desktop or run OpenTTD and other 2D games very well.
That said, it's been... actually a couple years since I've tried the proprietary driver, so maybe it's better now that Steam has moved over.
As for Nvidia, I have no first-hand experience, but I know they do not cooperate with open source software very much. It probably didn't help that Linus Torvalds actually gave them the finger a few months back.
nVidia proprietary drivers mostly just work with Linux, not to the same degree of performance as with Windows because they are not optimised for particular games, but certainly not bad. AMD Catalyst is just a mess, and AMD has fired almost all of it's Linux developers months ago, AMD is not a good choice for Linux anymore.
Check phoronix.com graphics benchmarks for open source drivers and proprietary drivers. For some OpenCL applications, AMD cards can be more scalable, but mostly, if you want to run GNU/Linux, get Intel or Intel/nVidia.
The card that runs best with Linux open source drivers is the old GeForce 9800GT/GTX/GT+, I actually still use a 9800GT for doing battle in Xonotic/Alien Arena/Red Eclipse/etc, because with the nouveau driver (open source), I get over 350 fps all maximum settings with red eclipse, and only about 220 fps with my 680 with nouveau, because the nouveau driver cannot make the card work at anything but lowest speed.
If you use a hardcore free and open source GNU/Linux distro, using the open source drivers is important to get support, because otherwise your system will be considered "tainted". I would definitely recommend getting a card that works well with an open source driver for a production machine, especially since the support is so awesome in the Linux world.
Obligitory Linus image, but in all candor. It depends on the card like the poster above said. I've had good luck with AMD and linux compatability and very few driver issues. Trying to get openSUSE to work with my laptop's nvidia gpu was a nightmare and a half. As for desktop cards and linux nvidia drivers I have no say as I don't know. You wouldn't go wrong with either. Best to look up whatever card you're looking at and see what people are saying about it.
Actually I just fired up the proprietary AMD driver on Linux Mint with my 7870. Amnesia and Crusader Kings 2 both run just fine, and videos finally work right.
Linus doesn't care about the proprietary drivers so his comment was in regard to kernel contribution. AMD definitly does more for their open source driver. If you want new features like wayland you have to use the free drivers and I would definitly go with AMD since the free Nvidia driver is like russian roulette.
If you want powerfull 3d acceleration on newer GPUs you need the proprietary driver. Since they share most code between operation systems they run pretty fast but none of them are as stable as the free Intel or AMD drivers. So... personally I prefere AMD (good experience, good quality/price ratio, free drivers, open standards like opengl and opencl instead of cuda shit) but the choice is yours.
On a side note, Intel only has free drivers so if you don't need a powerfull chip, Intel is the way to go.