Just a heads-up to help others avoid the mistake I made with XP12’s install location.

I had it on an external USB drive, which was running at 100% load. Simlink couldn’t retrieve data reliably, so it kept retrying every second causing constant stutters.  Navigraph support jumped on a Zoom call with me and quickly pinpointed the issue. I’ve since moved XP12 to my internal NVMe SSD — load times are way faster, stuttering is gone, and performance is solid (60–100 fps, dropping to 40s over dense areas like LA).

Huge thanks to the Navigraph team for the excellent support!

 

8 hours ago, MrBitstFlyer said:

Just a heads-up to help others avoid the mistake I made with XP12’s install location.

I had it on an external USB drive, which was running at 100% load.

Thanks for letting us know.

Now...most of us are probably thinking "why on gods green earth would someone install a piece of software that relies on quick access to it´s stored content on an external HDD??" - but I am sure you thought it was a good idea at the time 🙂

X-Plane deserves PCI-e motherboard-plugged nvme-2 disk 🙂 

It also deserves good cooling! Here in Porta Land where it has been terribly hot, I fly with a big fan directed to me and the desktop, which has the advantage of scaring the cat away from the cockpit, but even that way I was seeing 72+ºC CPU temps 😞 and the desktop fans didn't stop spinning the best they could... That triggers my OCD alerts that I am spending too much energy... 🤣

btw, I guess FS 2024 is presently more optimized and it doesn't hammer my CPU that much. In a day like yesterday I could see between 62-68ºC only...

Edited August 8, 2025Aug 8 by jcomm

2 hours ago, jcomm said:

btw, I guess FS 2024 is presently more optimized and it doesn't hammer my CPU that much. In a day like yesterday I could see between 62-68ºC only...

 @jcomm I think there is some misconception.

For the whole picture on power usage you would need to know how many Watts your computer is drawing. This is roughly equivalent to how hot it gets, but you would also need to monitor your GPU (and RAM) to get a complete picture.

It could well be that MSFS is more GPU bound, so the GPU will become hot but the CPU cores stay colder (especially since MSFS runs on many CPU cores, while X-Plane mostly runs on ONE core, only).

Another fact that many people don´t realize is that flightsimulators are coded to run as fast as possible. It´s like a care with the accelerator pedal welded to the floor. They will always try to give you the highest framerate possible, even if that is 150 frames per second.

This was never a problem in the history of flightsimulators, which always struggled to reach acceptable framerates and no one thought of artificially limiting that number to save energy until recent years.

If you want to save energy, the best way is to limit your framerate. That way you can actually "ease off" the accelerator when you don´t need it, like when flying over water.

11 minutes ago, Litjan said:

 @jcomm I think there is some misconception.

For the whole picture on power usage you would need to know how many Watts your computer is drawing. This is roughly equivalent to how hot it gets, but you would also need to monitor your GPU (and RAM) to get a complete picture.

It could well be that MSFS is more GPU bound, so the GPU will become hot but the CPU cores stay colder (especially since MSFS runs on many CPU cores, while X-Plane mostly runs on ONE core, only).

Another fact that many people don´t realize is that flightsimulators are coded to run as fast as possible. It´s like a care with the accelerator pedal welded to the floor. They will always try to give you the highest framerate possible, even if that is 150 frames per second.

This was never a problem in the history of flightsimulators, which always struggled to reach acceptable framerates and no one thought of artificially limiting that number to save energy until recent years.

If you want to save energy, the best way is to limit your framerate. That way you can actually "ease off" the accelerator when you don´t need it, like when flying over water.

Ah, nevermind about that "energy saving" statement... it was more of a joke 😉

The GPU is not that hot, in either sim.

My Xp12 runs with that flag on the executable that restricts fps to 30. I also tried with RTSS and Nvidia Control panel or Inspector, and for now will stay with that executable flag: --lock_fr=30

Xp12 runs with fluidity, and at present I am using only default scenery and weather, although I will probably end up adding again Map Enhancement Pro, and X-World...

 

5 hours ago, Litjan said:

Now...most of us are probably thinking "why on gods green earth would someone install a piece of software that relies on quick access to it´s stored content on an external HDD??" - but I am sure you thought it was a good idea at the time 🙂

Haha, yep… I am suitably embarrassed 😅 At the time it seemed like a perfectly reasonable idea - now I know better!

14 hours ago, Litjan said:

Now...most of us are probably thinking "why on gods green earth would someone install a piece of software that relies on quick access to it´s stored content on an external HDD??" - but I am sure you thought it was a good idea at the time 🙂

When I started out with XP11, I actually ran it from an external USB3 SSD, so I could have the exact same installation for use on both my laptop and desktop. This worked reasonably well, but of course not nearly well enough as from a SATA or M.2 SSD.

 

12 hours ago, jcomm said:

...but even that way I was seeing 72+ºC CPU temps 😞

That temperature is nothing. Modern CPUs start actually throttling at 95 or 100°C, so you're nowhere near the danger zone. The worst you lose at higher core temperatures is a bit of boost frequency.

Edited August 8, 2025Aug 8 by Bjoern

1 hour ago, Bjoern said:

Modern CPUs start actually throttling at 95 or 100°C

Maybe soo, but any reasonable tech would advise you too run it much cooler than required. The hotter it runs, even if it is in spec, the shorter its life will be.

That was true in past silicon generations but these days they're capable of running that hot full time. Only potential drawback is fan noise.

15 hours ago, mjrhealth said:

Maybe soo, but any reasonable tech would advise you too run it much cooler than required. The hotter it runs, even if it is in spec, the shorter its life will be.

Of course. But still, being >20 K below the limit is zero cause for concern.

34 minutes ago, Bjoern said:

Of course. But still, being >20 K below the limit is zero cause for concern.

Some guys run the same hardware for 15+ years (and are proud for being so frugal) and if that is the goal...then yes, using it little and running it cold should be part of the profile. Much like a historic car that you want to preserve for decades.

But it you upgrade to the next generation of hardware at a reasonable interval, then running "hot" (while staying within the recommended limits) should be of no concern.

"When the processor is operating at or near its maximum frequency it's possible for the temperature to climb very rapidly and quickly reach its maximum temperature. In sustained workloads, it's possible the processor will operate at or near its maximum temperature limit. Being at maximum temperature while running a workload isn't necessarily cause for concern. Intel processors constantly monitor their temperature and can very rapidly adjust their frequency and power consumption to prevent overheating and damage."

https://www.intel.com/content/www/us/en/support/articles/000005597/processors.html

 

The closest thing I could find for a thermal warning just now was a footnote on p.52 in their xeon guide:

https://www.intel.com/content/dam/www/public/us/en/documents/guides/xeon-scalable-thermal-guide.pdf

"The Short-Term Thermal Profile may only be used for short-term excursions to higher ambient operating temperatures, not to exceed 96 hours per instance, 360 hours per year, and a maximum of 15 instances per year, as compliant with NEBS Level 3. Operation at the Short-Term Thermal Profile for durations exceeding 360 hours per year violate the processor thermal specifications and may result in permanent damage to the processor."

That's referring to the 7th column in the table. T_case is the temp at the outside center of the heat spreader so life is going to be a handful of degrees hotter at the silicon itself. 90+ degs there. Xeons are the same manufacturing processes and materials as consumer chips. In other words, running up to 90+ deg during 15 min of takeoff/approach every day even a few times a day isn't going to be a problem.

Even if you don't trust your own choice of thermal paste and cooling system you'll be fine. Worst case scenario is that you see random poweroffs and perf problems.

Edited August 9, 2025Aug 9 by blingthinger

7 hours ago, blingthinger said:

Even if you don't trust your own choice of thermal paste and cooling system you'll be fine

Thats as long as you can trust the motherboard or CPU developer to have a bios that will do the right thing, which sadly lately is kinda having boundries pushed to get sales.

I feel more than embarrassed, I feel downright dumb for having installed XP12 on an external drive. Moving it to an internal NVMe SSD has completely transformed the sim. No more blurry textures, no CTDs, and Navigraph integration works flawlessly. I’m consistently seeing 60 fps+ in most areas, with dips over dense cities. Running on an HDR monitor with RTX HDR enabled gives a bright, high-contrast image, and flying over the UK with Orbx TrueEarth is both smooth and visually stunning.

 

9 minutes ago, MrBitstFlyer said:

I feel more than embarrassed, I feel downright dumb for having installed XP12 on an external drive.

No need to feel embarrassed, I think - it was an ill-informed choice made when you were not aware of the consequences, not a result of being unintelligent.

X-Plane does not rely on accessing data constantly as some other simulators do, it is actually a strength of X-Plane that it gets everything "loaded and ready" before you spawn in the cockpit. But naturally it can´t have the whole world ready, so as you fly along, it needs to load more content into the RAM/VRAM and how that goes depends on the bandwidth of your storage device.

This is ESPECIALLY true when using orthophoto based scenery - where each texture loaded is different. If you only use vanilla scenery, the total number of textures is much smaller and can probably loaded into RAM all at once (a meadow in the UK will have the same texture as a meadow near Chicago, whereas with Orthophotos both of them will have their very own texture).

The actual fps should not be affected - just like installing more RAM does not help with fps, but the overall smoothness (less lags for loading data) should be improved with faster storage access.

Edited August 10, 2025Aug 10 by Litjan