I had the same thing with NV GPUs like last week and just went to another project. Since They were not matched, a 1070 and 970, I didn't think they were being utilized the best. I tried the ngpus = 1 as well but the times did not line up. 22min for 1 task on both cards. 22 min for each task on d0 AND d1. One card should be faster than the other.

If I were to try again I was going to run another client and ignore the 1070 on one, and the 970 on the other to try and get separate tasks on each card.

You can use a line in your cc_config.xml file to do that:

<exclude_gpu>
<url>http://boinc.fzk.de/poem/</url>
<device_num>1</device_num>
</exclude_gpu>

Those lines tell Boinc to exclude gpu 1 from the project poem, when Boinc first starts up in the event log tells you which gpu is 0 and which gpu is 1.
Put it in the <options> section like this:

<cc_config>
<options>
<use_all_gpus>1</use_all_gpus>
<exclude_gpu>
<url>http://boinc.fzk.de/poem/</url>
<device_num>1</device_num>
</exclude_gpu>
</options>
</cc_config>

To exclude your 2nd gpu from say Collatz you would add more lines:
<exclude_gpu>
<url>https://boinc.thesonntags.com/collatz/</url>
<device_num>0</device_num>
</exclude_gpu>

You put that just before or after the other gpu exclude lines.

Put together that would mean gpu 0 can run Poem but Poem but cannot run Collatz, and vice versa for gpu 1.

<cc_config>
<options>
<use_all_gpus>1</use_all_gpus>
</exclude_gpu>
<exclude_gpu>
<url>https://boinc.thesonntags.com/collatz/</url>
<device_num>0</device_num>
</exclude_gpu>
<exclude_gpu>
<url>http://boinc.fzk.de/poem/</url>
<device_num>1</device_num>
</options>
</cc_config>

This lets each gpu run it's own project with it's own priority settings.

I had the same thing with NV GPUs like last week and just went to another project. Since They were not matched, a 1070 and 970, I didn't think they were being utilized the best. I tried the ngpus = 1 as well but the times did not line up. 22min for 1 task on both cards. 22 min for each task on d0 AND d1. One card should be faster than the other.