how to restart a failing gpu on driver level (w/o rebooting)
Posted: Thu Dec 01, 2011 8:51 pm
if a card is failing not only inside of octane but on driver level - typically from overclocking - mostly notable in ultra low performance and having the clock stuck at 405mhz, this tool should help preventing a reboot: http://answers.microsoft.com/en-us/windows/forum/windows_7-hardware/devcon-not-working-correctly-in-windows-7/9abcc12c-d7db-4249-aec4-fc4ff0ea6ee8 (description in the first accepted answer)
note: if you have no monitors attached to the card you may get the same result easier via the device manager, by just disabling the card and enabling it again, but as the device manager has no option to just restart a device, you should'nt ever do that if you use the card for main display, because it'll of course lock you out of the system - even after a reboot it won't become enabeleda gain (and the screen stays black!). also, if there are more cards and one of them serves for displaying windows, it isn't easy to figure the right one out, because the device manager has no numbering or usage information to the entries.
the "devcon" utility instead provides a way to restart a driver, which unlocks a stucking card and might(!) be save even in the case of having it as main display device (and saves click-thorugh time because of beeing a command line utility). btw, on windows 7 only the above link provides a way to get a working devcon version!
the tool needs to be run from the commandline; the syntax is easy:
devcon restart "PCI\VEN_10DE&DEV_1234567890XYZ" (with quotes)
the correct device string for your system is copy&paste available from the device manager:
administrative tools > computer management > device manager > graphics cards > your nvidia gpu(s) > right-click > properties > details > select hardware ids from the dropdown box ... normally there is more than one hardware id listed - the first one is sufficient. if there are more cards, the given hardware id affects all cards, thus the command as quoted above will reset all cards (ps: there are ways to address and reset only specific cards also).
imo it is not necessary to run it from an administrative cmd window but this might depend on uac settings. it is also possible to create a simple .cmd batchfile to run the command...
use with caution
note: if you have no monitors attached to the card you may get the same result easier via the device manager, by just disabling the card and enabling it again, but as the device manager has no option to just restart a device, you should'nt ever do that if you use the card for main display, because it'll of course lock you out of the system - even after a reboot it won't become enabeleda gain (and the screen stays black!). also, if there are more cards and one of them serves for displaying windows, it isn't easy to figure the right one out, because the device manager has no numbering or usage information to the entries.
the "devcon" utility instead provides a way to restart a driver, which unlocks a stucking card and might(!) be save even in the case of having it as main display device (and saves click-thorugh time because of beeing a command line utility). btw, on windows 7 only the above link provides a way to get a working devcon version!
the tool needs to be run from the commandline; the syntax is easy:
devcon restart "PCI\VEN_10DE&DEV_1234567890XYZ" (with quotes)
the correct device string for your system is copy&paste available from the device manager:
administrative tools > computer management > device manager > graphics cards > your nvidia gpu(s) > right-click > properties > details > select hardware ids from the dropdown box ... normally there is more than one hardware id listed - the first one is sufficient. if there are more cards, the given hardware id affects all cards, thus the command as quoted above will reset all cards (ps: there are ways to address and reset only specific cards also).
imo it is not necessary to run it from an administrative cmd window but this might depend on uac settings. it is also possible to create a simple .cmd batchfile to run the command...
use with caution