I think that MSFS benefits most from stability, and if there is extra room, a bit of extra clock cycles can help, a bit. I don’t think there is any real risk, as long as you check temps, and have decent cooling (this is why it’s a good idea to undervolt a bit, especially if adding to the boost frequency). Having PBO enabled will shut the CPU down if it hits any of the limits (Temperature, Power/watts, or Current/amps), but you still want to stay away from those limits just for stability and longevity. Up to 200 MHz doesn’t add a lot, but just check temps after changing settings.
With default settings for BIOS for the 9800X3D, I think it runs with a bit more voltage than most individual units need, and this means that when MSFS spikes, it might push temps and or power momentarily closer to the PBO safety limits (mostly that’s no problem). But there is room to undervolt modestly (eg All Core -10, or -15 on the negative curve offset), and this does create extra headroom to reduce temps, or allow for increasing boost frequency, or both, for those moments when MSFS hits the CPU and requires boost.
So I think it’s worth trying a bit of boost clock if you are curious to see what it does (it goes in increments of 25 MHz up to +200) if you are Main Thread limited, and provided you check temperatures and apply a modest undervolt if needed. It would just help a bit as you suggest. Probably more important is making sure EXPO is enabled, and if available try a High Efficiency Mode preset to tighten the memory subtimings a bit. That has impact. But as with all these settings, you need to try on your system to know how it behaves.
I’m pushing my set up a bit because I’m driving 3 screens, and want increased TLOD.
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Thanks for the information, appreciate it.
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This is an epic thread and am considering eventually upgrading my system (Ryzen 7950 and 5080) but I am thinking again since I have had nowhere near these problems and am running the 787-10 at a solid 72 FPS. Might want to stay with the devil I know.
Please note the 787-10 may be the most modern of the Boeing airliners but the MSFS implementation has a long list of bugs that may drive you crazy especially the clarity of the display… which never really got clear for me until the last NVIDIA driver. Many prefer other airliners…
Beautiful display(s), but I have come to prefer VR even in the 787 and the cockpit display is fine again with the latest driver.
Clear skys.
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The biggest benefit is most likely going to be with the 1% lows as your cpu will be able to absorb a few more of the stutters. Following a scientific methodology to tweak PBO settings as @GimbalAxis has suggested will ensure the risk is low.
I’m actually going to try to test if the boost clock helps, as I’ve just done a clean install. I may open a different thread for tuning experiments, but here’s some interesting info about how MSFS uses resources…
I've just done a complete reset, and am testing default stock settings:
- Erased my PC (I keep installers and backup on 2nd SSD)
- New BIOS, Windows 11 25H2, new Chipset Driver, latest NVIDIA 591.86.
- Stock BIOS settings for 9800X3D, no PBO or EXPO yet.
- Stock settings for RTX 5090, no undervolting yet
- Load MSFS, as if for first time, Graphics are:
- 4K 120Hz (single monitor for testing)
- DLAA at 100 (310.5.2 with preset K automatically applied) I’d normally use TAA but decided to test DLAA
- Max Frame Rate 60
- No Frame Gen
- Ultra Preset for testing with no changes
Using HWInfo, I’ve opened a few of the key metrics as graphs for a short flight - a simple circuit in the C172 from KTEB, flying around NYC for 30 min or so.
2 things stand out:
- The spikes in the CPU Temp whenever I change camera view, whether looking to the sides in the cockpit, or switching to external or drone view, there is a massive CPU spike. This is of course the MSFS function of jettisoning assets that leave your view, and processing what you’ve turned to look at
- The amount of data moving around in RAM, VRAM, and Virtual Memory. 42 GB of Virtual Memory allocated, but not sure how it’s used. I wish it was in RAM and not on disk. I have a fast SSD but I worry about the amount of wear. I’m going to re-do the flight with the SSD info open so I can see the read/write amounts.
So the boost clock may help in those moments of high demand, but the spikes show how it’s good to have a bit of headroom. This is just the C172, I’ve yet to test an airliner.
Since I was doing a full reset and clean install of MSFS, I decided to finally try to figure out how to Benchmark test using MSFS. It was a lot of work, but also a lot of fun.
TL/DR here's what I found:
- Enable EXPO. My G-Skill RAM is 5600 MHz at stock, and 6000 MHz with EXPO
- Enable PBO. Auto is good, but Advanced lets you access Curve Optimizer, and a modest undervolt of -15 reduces CPU power draw by 5 to 10%.
- GPU: A modest undervolt on an RTX 5000 series card really reduces power draw and heat, also by roughly 5 to 10%
- Tightening Memory Subtimings has a HUGE benefit. See the note earlier in this thread. I’m guessing because MSFS moves so much data around, timings really matter.
- Amount of RAM and VRAM usage seems to benefit from tighter subtimings.
- Adding extra Boost Clock helps a bit, and if combined with a modest undervolt, it would still run with less voltage and heat than stock.
Here was my process
I created 2 flight plans, both 20 minute circuits:
- Default A330, KJFK/31L GLDMN CASLE DPK KJFK/DPK.I31L
- Default C172, KTEB/06 JULEB RINNG HUDSN LBRTY LAYDE DANDY KTEB/06
I flew both flights under 4 tests:
- Test 1 - Stock
- Test 2 - EXPO, PBO, and undervolt CPU and GPU
- Test 3 - Tighten Memory Subtimings
- Test 4 - Add Boost Clock
My MSFS settings were:
- 4K (TV is 120Hz, VRR enabled)
- DLAA Preset K 310.5.2
- No Max Frames or Frame Gen
- Preset Ultra with no changes, so default Traffic was on
- Flights loaded with “Few Clouds” preset at noon.
- I have 3 screens, but used only 1 for this test
I opened the MSFS Dev Mode FPS overlay and HWInfo, and took screen shots at roughly the same points in each flight, and below are the numbers:
Test Setup
A330 at KJFK
C172 at KTEB
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