I haven’t monitored myself but there are some posts towards thie end of this thread suggesting that sim time keeping has been improved with the latest SU15 beta update. Maybe the light at the end of the tunnel…..
https://forums.flightsimulator.com/t/1-37-13-0-su15-beta-survey-stability-xbox/638223?u=cd0139
Hi,
It’s very obvious on the PMDG 737-600 with the UFT map enanbled…
Plane: 737-600 version .93
UFT version 1.64
This first video shows the aircraft sat still after a short flight during which the sim speed had been modified but was set back to 1.0X prior to the start of the video.
1drv.ms/v/s!AtQsPXDLGL9vgdQqCcztMUsYT2tSpg?e=jaKZ3W
I then went into the UFT and displayed the regular (not Navigraph) map and captured this second video.
1drv.ms/v/s!AtQsPXDLGL9vgdQpaNou5YhOjjq3tg?e=6dCJHX
Hopefully, you can see that the sim is almost running at half speed (based on the clock as shown but also very obvious when flying) whilst the sim speed remains at 1.0.
Closing the map down solves the issue immediately.
For info, the Xbox had been started from cold and MSFS started from fresh prior to these video caps.
I’ve tried to reproduce on the PC but can’t at the moment so I’d agree with everyone else about the Xbox CPUs being maxed out.
The odd thing about the above is that upping the sim rate to 2.0X makes the clock run pretty much to time - that seems like a very odd coincidence.
Regards, Neil.
Afraid to say even after updating to the beta a few days ago, I’m still getting the sim time slowing down. Was sat in the PMDG 737-800 (turnaround state) at a default airport (I think it was LEPA) and even just running the timer then, in around 60 seconds of ‘real time’ only around 45 seconds elapsed in sim 
.
Did a quick circuit and was still the same most of the way around.
I haven’t really noticed any other improvements, but appreciate the efforts. Have posted this in the beta discussion thread too.
No noticeable improvement in Sim Update 15 Beta 
Flying the Citation Longitude, “slow motion” is most noticeable during climb and cruise, something slowing down the time compared to real time. Surprisingly, the clock speeds up again during final approach and landing.
I discovered in the SU15 beta that switching the Xbox Series X to 60hz significantly improved this issue (i.e. switching the Xbox display settings). Obviously, this is not a perfect solution, because it removes 120hz for all games and apps on the Xbox unless you want to change that setting every time you switch to and from Flight Sim. But, at least for me, it was a huge improvement over SU14 (and, I don’t mind not having the potential for 120hz in other games).
@Spook524 you know I think you may be onto something, thank you! Finally got around to testing today with the latest beta, and having switched to 60hz and for the first time ever the clock in the pmdg 737, ATR and bae146 seem to be holding up ok! Maybe a small amount behind but it’s a marked increase on before. Tried at 120Hz earlier today and it was awful - around 70% sim time to real time. So 60Hz it is for now I guess, and here’s to hoping it stays that way!
Only slight issue is I’m getting lots of crashes (particularly the 737 with all avionics and flight controls going dead - so prob WASM issues, perhaps ones they already know about?) but the clock was running fine so hopefully something to be sorted before release of SU15. And hoping that it wasn’t just running fast because none of the plane’s systems were actually running.
Thanks again!
Edit: Worth noting I’m still only testing with default airports for now and away from big cities
Its doing this on a320 v2 on Xbox series x
I use 60Hz since long time. You also can see that the jitter of the world globe (splash screen during startup of fs2020) is much less.
On the other hand regarding time: I realized that when doing a group flight with same airplanes my (XBox) airplane lags behind the PC airplanes even with the exact same speed and environment (temperature etc) settings.
Am having this exact issue right now and its frustrating as well. Been playing flight simulator since it came out on xbox and only started occurring this issue about 2 months ago when i noticed i finish last in near all group flights by around 10-15 mins or even just flying with a friend with same speeds and weights. You can tell by the clock on the PMDG 737-800 definitely runs slower but this was worse on 120hz so had to drop it 60 which helped alot by a good few seconds but didnt fix the issue. So frustrating when all i wanna do is fly but dont want it to taoe say 30mins 45min extra for a 2hr flight say. Hopefully this is fixed for MFS24
I think that’s the worst part with the clock slowing down your flights are longer.
Needs fixed
Been messing on today with refresh rates etc and no real difference still runs slow
I’ve got msfs on a separate 2tb ssd into back of Xbox. I wounder if this can cause issues ?
120hz
Vrr on 12 seconds
Vrr off 7 seconds
120hz game mode
Vrr off 6 second
Vrr on 7 seconds
Auto low latency 9 seconds after
Loads of setttings effect how far the sim runs behind
I’ll try 60hz later but ideally don’t want to as it’ll sputter so I think my only option is play for now and when 2024 comes out get a gaming pc
Has anyone tried how the Xbox performs if lowering the console display settings to 1080p and 60hz? Im wondering if lowering the display settings would help the sim keep time better…
Noticed clock slow in the A320 v2 (Xbox) tonight. This is the first time I’ve seen this. 10sec on the a320 clock is equivalent to 13 sec in real world time.
Lucky for you it’s the first time you’ve noticed! I think it may have to do with servers… the sim just can’t quite keep up and it drops time to keep things running. Were you flying in a busy area or around large cities or addon airports?
Just realised that the only difference tonight was a change in settings to traffic - live traffic on. Perhaps too much for the CPU?
Yes, that could be. That’s more data the sim is trying to feed into the environment… maybe it put you over the top. I still think there is a server component to it. If you fly at the same time and in the same area as a bunch of other folks I think it slows it down.
For those a bit newer to this topic and perhaps unaware, this problem was discussed in some detail during the November 2023 developer livestream. I had submitted a question about this problem and it was discussed in some detail. That said, the discussion did unfortunately boil down to Asobo needing to investigate it. I’ve neither read nor heard anything substantial about their investigation since it was raised last November.
During that livestream, Asobo did say that MSFS doesn’t use the system clock, but rather a hardware clock. In addition, because of how MSFS is coded, there are two or even three (or more) separate clocks running concurrently for different things. They alluded to the problem perhaps being related to the Xbox becoming bogged down while running MSFS and the resulting low framerate affecting the clocks.
On PC, in my experience the clocks keep time perfectly. So, I suspect the problem is related to how the clocks are affected by the heavy demand MSFS generally places on the Xbox hardware.
I do recommend reading the relevant portion of the transcript. It is titled “Time running slower on Xbox” under the Q&A Session 2 sub-section, and is available at this link:
As far as I know the XBox has no hardware clock like a PC does. This requires to calculate time by software which in turn can result the time calculation not accurate under heavy load.
The Xbox is architecturally pretty much identical to a Windows PC, and has a realtime hardware clock just like your PC. It remembers the time of day and shows a clock on the home screen.
The problem is definitely not that the Xbox hardware or operating system doesn’t know what time of day it is: it’s most likely a problem in how the game keeps track of time passing in the simulation – the slow per-core CPU performance on Xbox is likely exacerbating any timekeeping problems with frame pacing far over what most PC users see.