Two GPU's: how does Resolve choose one? Can I override?

Hi all,

So I've just upgraded my system from running on one GTX750 (2GB) to running on a GTX750(2GB)+GTX1060(6GB).

[ I'm using the free version of Resolve, and I know that only supports one GPU. Once I buy it, I will be able to configure two I suppose, so that will be soon I hope. ]

Of course I was eager to see how things went. I installed the GTX1060 in the top PCI-e lane where the GTX750 was before, and moved the GTX750 to the second slot, halfway down. I connected my two Acer monitors to the GTX1060. The two cards are not linked.

So far so good, the PC runs and the monitors work of the GTX1060. Using CPUID HW monitor I see the GTX750 is idle.

Now, when I start Resolve, I expected the GTX1060 to be visible in the preferences, but instead, I see Resolve picks the GTX750 as it's GPU. Why is that?

If I do an operation like generating optimised media, I can see it's being done on the GTX750 and the GTX1060 is almost idle.

If I playback a short timeline with just 2 clips and a transistion, I can see BOTH cards active. Wasn't there supposed to be only one card in use?

So my questions are:
- How does Resolve choose it's GPU?
- How can I change that in the free version?
- Is it maybe Resolve chooses the GPU that does not have monitors on it to compute?

Obviously I want Resolve to run of my new GTX1060...

My system is working, the monitors are working, there are 2 different cards in the machine (i7-6700 / 16GB / Win10). So how do I get Resolve to use the new card instead of the old one (which has moved from a PCI-e 16x to a PCI-e 4x lane).

Any info or links to answers and tutorials are welcome. I'm in the process of optimising my hardware and studiogear prior to buying into Resolve.

regards, Frank

You should plug your monitor into the weaker card...resolve will use the GPUs not connected to a display for computation.

In your preference window you can tell resolve to not use display GPu for computation. There is also a switch to automatically select GPUs or to manually select them for computation.

Unless V15 has changed, in the past your maximum VRam that could be used by Resolve was determined by the card with the LOWEST speed and LEAST amount of RAM x 2.

So even if you upgrade to the paid version, unless you buy another video card with the same speed and amount of RAM, you'll still want to leave the displays on the lower powered card and tell Resolve to NOT use it for computation.

With your current system, you would lower the entire system VRam to 4GB if you tried to use both cards.

I had a similar situation on my home system when I upgraded to 12.5 and had to remove my lower powered card entirely for Resolve to run effectively on the newer, higher powered card.