I am planning to build a new computer on which I will run Ubuntu Linux.
Now, which motherboard and which graphic card has the best support for Linux?
I have a NVidia MB which you can get to work in Linux, after some work. And an ATI graphics card which on good days works ok, but doesn't really interact with Ubuntu software systems, so many upgrades causes graphics to just break.
Any recommendations on what I should go for when replacing the old computer?
/Leif
I have always found nvidia plays best with Linux. If you think you might be decoding HD x264 video, get one with vdpau support. Intel chipsets also work pretty well in my experience.
Intel GMA drivers are open source and fully integrated and supported on linux kernel.
Nvidia drivers are propritary (you can find a open source alternative, but, imho, they are less powerful than the officia) but they works fine.
ATI has some problems, but the specs are released, alternative support is possible...
Even so depending on the final use... Intel chips are not really powerful for a advenced use, nvidia seems to be the best choice.
As of 2012 there are basically no problems with major mainboards using AMD, intel or nVidia chipsets, nor with AMD or nVidia discrete graphics, nor intel or AMD integrated graphics. It all just basically works. If you try to install proprietary drivers you can sometimes get into trouble, so learn how X Windows is actually configured and be ready to install & remove fglrx (AMD) or its nVidia equivalent. In general though "sudo sh [AMD installer script] --force" will install the AMD proprietary drivers and "sudo aticonfig --initial" will configure it. SMXI.org has some tools to install video drivers and tricky stuff like VMware (on Debian at least). So compatibility (the first requirement for "best") is usually easy to satisfy. CPU usage (therefore heat and power) is lower with the open source driver however http://www.phoronix.com/scan.php?page=article&item=amd_comp_oktoberfest&num=36 so be sure you really need high resolution & more than two monitors before you install proprietary drivers.
Second, let's look at power consumption, a major reason people move to Linux and probably the major reason people permanently retire desktop boxes rather than putting them in another role. http://www.phoronix.com/scan.php?page=article&item=amd_comp_oktoberfest&num=38 shows you how some video cards perform. An AMD FM1 (or soon FM2) socket or one of the very low wattage intel Ivy Bridge processors give you some sub-20-watt options with good graphics (AMD's are better) if power is at a real premium. ASUS, Gigabyte, etc., make some very reliable boards for both breeds.
Regarding performance in a particular role, there is no shortcut to figuring out what apps you are running. An app-specific analysis starts here http://www.phoronix.com/scan.php?page=article&item=amd_comp_oktoberfest&num=21
And a processor benchmark is over-rated. You are better off putting more money into RAM, regardless of CPU, generally. More RAM, not faster. Then, a PCIe SSD (not a SATA6G SSD). If you spend $300 on that stuff and have a $200 AMD processor instead of a $500 intel one, you will probably be better off in almost all applications, especially if you can replace the AMD processor with a much faster one later in the same socket (get an AMD FM2 board as soon as they're out). http://pcper.com has a fair bit of information also on hardware but Phoronix.com is better for Linux comparisons.
I have historically always had problems with ATI proprietary video drivers in Linux. ATI did not and AMD does not make a serious commitment towards supporting Linux well, and therefore have always had a pretty hacked-together installer that tends to be quite fragile.
I've had problems upgrading drivers where the new driver simply doesn't work at all. I've also had problems with acceleration simply not being enabled when starting X-Windows. Both are really quite a pain to fix as well.
If you want a good, proprietary driver with acceleration, Nvidia is the way to go, in my opinion.
