Changed RAM CTD

Hi All, been really happy with how MSFS2020 has run on my machine. Never had any bother, good Graphics and decent FPS and no real issues. When my PC was built, I noticed my RAM was in the wrong slots on the motherboard for the speed, i.e my RAM is 3600MHZ but the 1 & 3 slots in my Motherboard only went to 2100MHZ, where as 2 & 4 went to 3600MHZ. So I swapped them over, enabled XMP2.0 on the BIOS and everything is running sweet. Only now I get random CTD on flight sim. Either on departure or approach. Really frustrating. Just wondering if anyone else has had something similar.

Specs are:

ASROCK X570 Taichi MB
2 x 32GB 3600MHz Hyper X
AMD Ryzen 9 3900X

Had no other problems with any other game I play.

Did you run a memory stress test?
Check for new BIOS.
Also check Memory QVL that your memory is supported/tested.
(edit: I don’t see 32GB planks on QVL list, perhaps you should consider changing to 4x16GB.)

Anyway, it looks like hardware issue rather than software, and unlikely MSFS.

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My personal experience is that XMP profiles will not run stable with 64GB RAM. Just set your RAM timings manually to 3400MHz or 3200MHZ and you should be fine. There won’t be any noticeable difference performance wise.


hi there…u mentioned a very interesting point…i just bought a Lenovo legion T528imb05 with 16 gb ram…i bought also a additional 16 gb ram Crucial CT16G4DFD8266 16Go (DDR4, 2666 …the original ram was put in socket 2. i put the crucial on socket 3…but according to memoryQVL, the sockets supported for that speed are 2 and 4…so does it mean that i have to replace my crucial on the socket 4 ??? i noticed when using the sim that only like 16 ram are used ? could it be the reason ? so move my crucial from 3 to 4 ? thanks

I by no means have any expertise in this area, but I know that pairs of memory go to alternating slots: 2+4 and 1+3, with 2+4 usually being preferred pair of slots. 2+3 should work, but will only work in single channel read/write mode (while 1+3 and 2+4 work in dual channel mode).

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thansk…and this single and dual channel thing…what does it mean ? it will increase speed of the ram ? will go faster (sorry for my ignorance…)

i just checked again, the origial samsung ram is in slot 1 and my crucial on slot 3… should i change their slots loctaion ?

YouTube is your friend about this.


1+3 should work in dual channel. Dual channel allows sending data between CPU and RAM twice as fast, but it does not necessarily gives increase in games etc.
There are many nuances about memory, especially of different brands - are their speed and timing same or different? System may have reverted to safe speed 2133 when you added new memory - did you check in BIOS?
But it is very off MSFS topic, so better to be asked on specialized PC hardware forums, e.g. PBH - PcBuildHelp (

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lol…indeed…also my google friend…

MSFS runs very sweetly on my G.Skill PC-3200 @ 3600MHz (14-14-14-34) but any more and MSFS crashes to reboot. Stress tests are fine and so far only MSFS does this so I suspect it’s something they need to look at. With slacker timings this ram should be able to hit well over 4000MHz

B550M + 3800X

Edit: having just installed Windows 11 I’m going to try again with a faster clock.
Edit, edit: Seems to fly ok but then Esc caused a CTD … back to 3600

I thought this, disabled XMP and set to 3200MHZ, did a test flight and just got a CTD :frowning:

■■■■, FS2020 seems to be sensitive. I don’t get this with any other games I play.

Keep lowering RAM speed and see if it stops CTD. It could just be bad RAM or something else entirely.

Setting XMP usually requires setting the voltage as well in my experience.

My board wont even boot properly with XMP enabled if I do not set the RAM voltage to 1.35v which is it’s intended running voltage.

Just trying now with a default 787 just to make sure it’s not the A32NX mod causing it by coincidence.

Salem978 - Yeah my XMP profile defaults to 1.35v.

Rule number one with MSFS CTD is not tinker with RAM. I think I have seen around 30 or more people on this forum since the launch who fixed their CTD by getting their RAM to stock settings.

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If you are comfortable with it try not just accepting the XMP setting but set it to 1.35 yourself. I know it should make absolutely no difference but it consistently does for me.

Interesting, when you say stock, you talking stock speeds like 2100MHZ in my case?

Just launched a 787 on AP and let it run, no CTD, so it may actually be the A32NX mod. The RAM maybe a red herring as I’m still running the same speed.

Interesting dude, I’ll have a look cheers.

When you set XMP profile automatically change speed, timings and voltages.
I have 64g Gskill 3600 with out any issues.

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