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PC unstable when RAM are overclocked

Level 7

I'm writting you today beacause I'm facing an issue and I don't know how to resolve it. When I try to overclock RAM using (XMP 1 or 2) my pc is unstable.
First of all I tried with 4266 mhz (XMP 1 or 2). it's very unstable and I get a BSOD after less than 10 min.

I tried with XMP 1 and 4133 mhz, it's more stable but if I do not get a BSOD, applications like CSGO, Discord, Spotify.... often crash.
I have reinstalled Windows 11. While overclocking my ram I have left AI overclock do the job fot the CPU. I checked manual config with XMP 2 and everything was right.

Here is my config :

CPU : Intel Core i7-9700K (3.6 GHz / 4.9 GHz - Coffe Lake)
RAM : G.Skill Trident Z Royal Elite Silver RGB - 64 Go - DDR4 4266 MHz - CL19
COOLER : Noctua NH-D15
MONITOR 1 : AOC 144 Hz / VA (Curve)
KEYBOARD : Razer Huntsman Mini (Optical Linear Red Switch)
MOUSE : Razer Viper
MOUSEPAD : Artisan Ninja FX Zero Xsoft XL
HEADSET : Logitech G Pro X

Do you have any idea ?

Hi Sadlquea,

Welcome to the ROG forum.

When running high capacity/high speed ram such as yours, it comes down to if the cpu's memory controller or motherboard can handle it.

You have Samsung TridentZ Royal 64GB at 4266MHz, that's asking a lot in my opinion but it seems you're getting close and may have a chance to get there.

You're likely going to have to raise some voltages, I see XMP sets Dram voltage to 1.50v

I'd try

Dram voltage - 1.55v
CPU VCCIO voltage - Up to 1.30v
CPU System Agent voltage - Up to 1.30v - 1.35v

These would be the maximum voltages I'd try. If you can't get 4266MHz stable, you may have to settle for a lower speed or try 32GB with two sticks.

Hello Nate152,

First of all, thanks for your help.

I have noticed that CPU VCCIO voltage was set to 1.35v
I changed it to 1.30v and it was more stable with 64gb of RAM at 4266mhz.
However it crashed one time, so I have setted the frequency to 4133mhz and I'm still testing. No issue for the moment

I don't know why on Asus website the motherboard spec tell it support 4266mhz and on other website only 4133mhz

Asus :
Materiel :


I trust what the ASUS website says with supporting 64GB at 4266MHz. But it doesn't mean it's guaranteed to run, it's up to the cpu's memory controller if it can handle it.

The voltages I listed can help stabilize high speed/high capacity ram, but too much voltage could eventually burn out the cpu's memory controller.

I would still consider 64GB at 4133MHz outstanding.

I got one BSOD with 1.30V vccio and 4133 mhz in two days and it was when I was streaming and playing CSGO.

I succeed to stabilised my computer by downgrade VCCIO voltage.

Should I downgrade it again to avoid BSOD ?
Maybe it will be more stable and I will not get BSOD again


You could always loosen the timings a little to see if this helps stabilize things, loosening the timings may let you go higher with the frequency.

There are a few potential reasons why your PC might be unstable when overclocking your RAM. One possibility is that your power supply isn't able to handle the extra load, and another possibility is that your motherboard may not be designed to support overclocking.

Another thing to consider is whether you're using compatible memory modules. Some modules are specifically designed for overclocking, while others are not. If you're not using compatible modules, there's a good chance that you'll experience stability problems when trying to overclock your RAM.

Finally, it's important to make sure that your system is adequately cooled when overclocking your RAM. If the system gets too hot, it can cause instability issues and even damage components.


I ran some test with aida64 with intel turbo activated and RAM speed set at 4133 mhz, VCCIO and VCCA are set to Auto.

After 10 min I got an hardware failure. Moreoverver when I play a game that is called GTFO and when I set FPS to unlimited, my PC instantly crash when loading the map.

My motherboard is a Asus ROG STRIX Z390-E GAMING, and RAM are G.Skill Trident Z Royal Elite Silver RGB - 64 Go - DDR4 4266 MHz - CL19 so it should be ok with overclock

Also I have 750 W PSU. I calculated on a website and it told me 650W was enough

Do you have any Idea ?

Super Moderator
64gb over 4K is going to be tough. Not all Coffeelake CPUs will do this.

Lower frequency to 4000Mhz from 4133 and see if things improve.

Here is a previous venture on the Maximus Formula (Z390) for 4x8GB 4266 GSKILL. This alone required some concessions to tertiary timings to find stability.

VCCSA is CPU specific and too much voltage can hurt stability just as much as too little, so tune accordingly.

13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Level 11
64G @ 4133 Mhz is a stretch indeed.....its all about your CPU Memroy Controller as others stated.

If you must run 64G RAM (vs 32G), then knock the speed down until its stable, as in try 3800 - 4000 Mhz (leaving Timings alone).

Or as was pointed out above, try 4133 but try loosening Timings.

I felt pretty fortunate having 4000 Mhz DDR4 32G RAM run stable on simple XMP, but I did bump the VCCIO and SA up a bit regardless and it was also with a good kit of Royals and a Maximus Extreme Board.