Reality Capture 1.3 GPU Utilization Question

[CharlestonChu]

Hello there,

I have a 2 PC’s that I use for creating assets using Reality Capture 1.3.

The first PC has 2 Nvidia RTX 3070 ti’s, and the 2nd has an RTX 3070 ti, and an RTX 1080.

I wanted to run some solves through each machine, using identical datasets, while altering which GPU’s were being used on each machine so that I had a baseline idea of how long a solve at various quality levels would take on each machine, etc.

The results I have gotten don’t quite make sense to me, so I was wondering if anyone would happen to know why I am seeing what I am seeing!

For the first PC (2x 3070 ti’s), using just one of the 2 3070s has an average overall processing time that is nearly 40 seconds faster than using both of the 3070s, and on the 2nd PC (1x 1080, 1x 3070) I have found that the 1080 somehow has an average overall processing time of 40 sec. faster than the 3070, and 20 seconds faster than using both of the GPUs.

I know that 40 seconds is not a long time to wait for the processing to be finished, but I am more so wondering why I am seeing the results I am seeing, especially regarding why using 1 GPU seems to be faster than 2, but that could be my limited understanding of how exactly RC utilizes the GPUs.

Thanks in advance for any input or answers that anyone may be able to provide!

[OndrejTrhan (otrhan)]

Hi @CharlestonChu
Using two GPUs should be quicker, but it depends which part of the process you compared, as not all processes are using the GPU.

[CharlestonChu]

Hey @OndrejTrhan , I was just comparing the “overall processing time” shown in RC, but I am aware that not all processes utilize the GPU. Which processes use the GPU so that I can be more accurate in the stats I’m watching?

Thank you

[OndrejTrhan (otrhan)]

Hi, check this post: which operations require GPU? - #2 by OndrejTrhan

[CharlestonChu]

@OndrejTrhan Thank you so much for all this info, it helps a ton!