A few days ago I finished a build, including two Titan XP. The goal was to get faster rendering, letting the gpus work as two seperate cores that render two chunks at the same to nearly double the rendering-performance. So I disabled SLI in Nvidia Control Panel, selected both gpu's in the preferences tab and selected Cycles, using a simple scene at 4k.
The performance of the Titan XP should be circa at the level of the 2080 TI, as I saw in a few benchmarks. So two of them should be significantly faster (I read that two identical gpu's, that are not running in SLI should nearly double the performance). But they rendered nearly at the same speed as the 2080 TI/a single Titan XP, so there was no improvement. CPU, Mainboard and RAM shouldn't bottleneck (7980XE, 32Gb, Asrock Taichi CLX), I'm using Blender 3.0 with no add-ons and I installed the newest graphic drivers.
I tested a few different things: only selecting one of the cards in Blender - both of them work perfectly fine
monitoring the load of the gpus - both run at 100% with SLI disabled (MSI Afterburner)
removing the SLI-bridge - changed nothing
enabling SLI - was a little bit faster than a single card, but maybe only about 20-30%
trying different tile/chunk sizes
But nothing helped.
So what can I do, to get the cards work together? What have I forgotten? And is it possible to get the cards working on different chunks/tiles in Blender 3.0 as I described above?