I did a quick test to collect some data regarding VRAM usage. I’d like to share my results in hopes that it will help others.
i9-12900K, RTX 3090 with 24GB VRAM, 64GB DDR5, 1TB M2.NVMe, GR 522.25 driver, Win11 22H2, DX12
I started with MSFS’s 2D graphics render quality preset to Ultra, which sets all settings, including Texture Resolution, to Ultra. Monitor is 4K at 3840 x 2160. TAA 100, FSR 100. TLOD 200. I then changed only the Texture Resolution setting and restarted MSFS before each test.
I’ve both the Obrx YBBN airport and Brisbane City Pack installed. I chose the GorFriends Optica with departure from runway 19L. Preset time of 11:30 AM and preset weather of Few Clouds. I then recorded VRAM usage at time of spawning into the flight and then watched VRAM usage as I took off and flew directly to Brisban city center. I flew one loop around the city at low atlitude and returned to YBBN.
VRAM usage:
Ultra - 14.5GB on runway, 15.8GB over city center
HIgh - 11.5GB on runway, 13.8GB over city center
Medium - 9.7GB on runway, 10.1GB over city center
As one can see, the Texture Resolution setting has a sizable impact on VRAM usage. Once VRAM is exhausted, you’ll start to see FPS drop and / or a “pulsing” stutter effect.
I’ll also point out that I’m using DX12, which eats up more VRAM than DX11. I’d expect the VRAM usage for these tests to be a bit lower if / when using DX11.
In summary, those struggling with poor performance should take a closer look at VRAM usage. If your GPU’s VRAM is exhausted, try lowering the texture resolution setting until you find a happy place. You can then fiddle with TLOD setting to further fine tune VRAM usage.
Personally, I can’t see an appreciable visual difference between the Ultra, High, and Medium Texture Resolution Settings. But I sure did see the peformance degredation that VRAM exhaustion creates when I was using an RTX 2070 and 3070, both with only 8GB of VRAM.
You’ve got nothing to loose in trying a lower texture resolution setting other than a few minutes waiting for MSFS to restart. 