So I have completed my upgrade from a 5800X3D/RTX3090 to a 9800X3D/RTX5090. For the first part of the upgrade (CPU/RAM/Mobo change only), please see my previous post here. The graphs below are showing only the change from a 3090 to a 5090.
TL:DR
The upgrade from a 3090 to 5090 yielded a 40-80% improvement in MSFS2024. The older sim MSFS2020 showed a 39% improvement in GPU limited scenario, but the same FPS in the most CPU-heavy scenario (Fenix A320 + iniBuilds EGLL + FSTraffic). MSFS2024 was never CPU limited in any of the tests.
Test Conditions:
RTX3090 24GB → RTX 5090 32GB
Ryzen 9800X3D
64GB 6000MHz (2x32GB)
M.2 SSD 2TB
Win11, HAGS On, Game Mode Off
MSFS 2020 SU15 DX12 / MSFS 2024 SU2, Ultra Preset, TAA + 100% Render Scale 3840 x 2160, Terrain LOD 200, No FG, 500Mbps internet
Scenario 1
As usual I have my 2 go to tests. The first scenario is the Fenix A320 taxi @30 knots East to West along one of the taxiways at London Heathrow (iniBuilds EGLL in both 2020 and 2024), FSTraffic, cockpit view, scattered clouds. I also chose to set the time to an early winter morning where the shadows are long. This is generally my most-CPU limited scenario.
MSFS2020
MSFS2024
In MSFS2020 there was essentially no change upgrading to a 5090. This implies that the 9800X3D was the limit in this scenario, even with a 3090. My previous CPU upgrade from a 5800X3D to a 9800X3D unlocked a 16% performance improvement, but it seems that it is still the CPU which is holding back the system in this test, at least in MSFS2020. The framerate graph did pick up at the end for the 5090, presumably because most of the airport was behind my viewpoint.
MSFS2024 is a different story. There was a whopping 40% improvement in FPS, and a big uplift in the 1% and 0.2% lows. This suggests that the better multi-core support in MSFS2024 is shifting the burden off the CPU and onto the GPU, allowing the 5090 upgrade to really show.
Scenario 2
Beechcraft Bonanza starting on runway at Tokyo Haneda, take off and fly at 1000 feet North over Tokyo, scattered clouds.
MSFS2020
MSFS2024
This test was always GPU limited in all my testing to date, and it shows with a 39% improvement in MSFS2020 and 80% (!) improvement in MSFS2024. This was a very surprising performance improvement in 2024, much more than I was expecting. The frame rate graphs in 2020 start off at a similar place in 2020 for both the 3090 and 5090, suggesting the sim is CPU limited on the ground. Only when at 1000 feet does the CPU load lift. If I had started the test in the air the performance uplift in 2020 should have been even higher than 39%.
In summary, I am very pleased with the upgrade to a 5090. Coupled with frame gen and the performance is sublime. In 2024 I cap the framerate in game (user.cfg) to 45, and force 3x FG in the Nvidia App to get 135FPS. There is very little artefacting and the Gsync picks up when the real frame rate drops to the high 30s.
For those interested, these are the initial screen captures for each test with dev mode turned on. Mouse over the images to get the title for each test.
