Hello Randall, As far as I know, if you don't set particular device the device with index 0 in cuda device array will be used (at least tried to be). Otherwise, you can use cudaSetDevice or cudaChooseDevice
Regards, Alexander On 03.05.2011 19:06, Randall Mackie wrote: > I have access to a computer with a GPU, and I wanted to play around a > bit with petsc on this gpu. > So I have compiled petsc-dev with cusp, thrust, and cuda to give GPU > support, and I am ready > to run some examples. > > However, something is not clear to me: how does petsc know which gpu > to run something on? > For example, this machine has two gpus: one for the display, and then > one compute gpu. > So I see /dev/nvidia0 and /dev/nvidia1. If I just issue the command > from the petsc web page, > will it run it on the right gpu? > > > Also, what if a computer has two compute gpus? Does petsc use both of > them or only one? > > > Thanks in advance, > > Randy