MSI Afterburner a pretty useful program for Windows, and works well even if you've got more than one graphics card. Since it was one of the main reasons I was still running Windows on my desktop, so I decided to see what was out there for Linux. Turns out that there are multiple guides and tutorials out there, and it's entirely possible to set it up for Linux, at least for Nvidia. I have a GTX 560TI and a GTX 480, so I set mine up around that in Mint 15 (raring package base). If this guide is useful to you, feel free to adapt it to your own setup as needed. Others on FF also have experience doing this sort of thing, so post below if you need.
1) In a fully updated environment, first install the Nvidia drivers. I chose the 310 drivers from the official repos as they seem to work pretty well. The drivers should also come with nvidia-settings, which is GUI for changing these settings. You should be able to modify the /home/.nvidia-settings.rc file manually if your build is headless or if you prefer CLI.
2) Restart.
3) Open nvidia-settings and then save the current configuration to the xorg.conf file. Make a backup of this file just in case things go downhill.
4) Coolbits needs to be enabled for the Nvidia drivers to display the advanced settings. This is really easy to do if you've only got one GPU, (follow this guide by bollix47) but the problem for multiple GPUs is that coolbits requires that an X server be running on each GPU. If you only have a single monitor, you have to trick X/Nvidia into thinking that you've got a second one and you need another X server instance. Fortunately, this is not hard to do. First you need to know how to connect to the other GPU(s). Run the command "lspci | grep VGA" and you should see all the GPUs that are connected to your motherboard. There are three numbers at the beginning of each entry, you'll need those later.
5) Open xorg.conf in your text editor of choice. The filepath is /etc/X11/xorg.conf. Under the ServerLayout section at the top, you'll need to make an entry for every card you have. You should see "Screen 0 "Screen0" 0 0" already listed, so just make another entry. In my case, I put the coordinates at 1600 0 because my actual monitor is 1600 pixels wide. There are likely a number of values that work for this, but that was the one that I went with.
6) Create a Monitor section for the other GPUs. You should already see one listed, so under it you can write
Code: Select all
Section "Monitor"
Identifier "Monitor1"
VendorName "Unknown"
ModelName "CRT-0"
HorizSync 0.0 - 0.0
VertRefresh 0.0
Option "DPMS"
EndSection
7) Still in xorg.conf, create a Device section for all the other GPUs that you have. You should already have one listed, so just copy-paste and use it as a template. Change the BoardName entry accordingly. Use the three numbers you obtained in step 4 here, and apply them to the BusID. Make sure the formatting is good.
8) Ensure that every Device section has an Option with the values "Coolbits" "5". This enables the extra controls in nvidia-settings.
9) Create a second Screen section, using the existing one as a template. Here's my entry, it should work for you:
Code: Select all
Section "Screen"
Identifier "Screen1"
Device "Device1"
Monitor "Monitor1"
DefaultDepth 24
Option "ConnectedMonitor" "CRT"
Option "Coolbits" "5"
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "CRT-0"
Option "metamodes" "nvidia-auto-select +0+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection
10) Ensure that every Screen section has a "Coolbits" "5" entry. In the end, your xorg.conf should look very similar to mine: http://pastebin.com/EmCNt5GX
11) Restart.
If all goes well, your desktop should boot properly and under nvidia-settings you should see a fake CRT-0 display under "X Server Display Configuration", along with more than one X Screen listed on the left, and the advanced features such as fan settings under the "Thermal Settings" subsection for each GPU. On my machine, the Cinnamon desktop under Mint 15 didn't like this hack and reverted to Fallback Mode on startup. If anyone encounters this and has figured out how to fix it, please let me know. KDE seems to work fine though, it's easy to switch desktops.
Enjoy!
