System won't POST with four sticks of RAM

BUDFORCE · 28 Jan 2021 at 14:05

Hang on, you were trying to use 4400mhz RAM downclocked significantly, then 4133, then 4000, the 4000 worked, clocked down to 3733.

Seems you are putting in RAM of a much higher frequency than the CPU can handle at stock speed, and/or that you intend to run the ram at, then the lowest frequency kit worked?

I am guessing here (stress that) but isnt that a factor here?

Maybe something in the bios was defaulting/clocking the ram at the original rated speed and it was soiling itself, or maybe the RAM itself doesnt like being run at such lower than rated speeds? Enough to work with 2 but not 4?

Just wierd how the RAM with the lowest stock fequency and that closely matches what you are actually running it at worked.

Zen 2/3 are notorious for being fussy with ram, although most people put lower stock ram and try and overclock it, you are doing the opposite, maybe it doesnt like it either way.

philo-sofa · 28 Jan 2021 at 14:58

BUDFORCE said:
Hang on, you were trying to use 4400mhz RAM downclocked significantly, then 4133, then 4000, the 4000 worked, clocked down to 3733..

Originally I was using 4133, downclocked to 3800. I never used the XMP profiles so set it to 3600MHz and 1.35v at first, then 'overclocked' it to 3800. It all worked until it failed to POST one day, which is a key piece of evidence.

Then I tried a 4400MHz set and it wouldn't post, and finally four 4000MHz DIMMs.

BUDFORCE said:
Seems you are putting in RAM of a much higher frequency than the CPU can handle at stock speed, and/or that you intend to run the ram at, then the lowest frequency kit worked?

I am guessing here (stress that) but isnt that a factor here?

Maybe something in the bios was defaulting/clocking the ram at the original rated speed and it was soiling itself, or maybe the RAM itself doesnt like being run at such lower than rated speeds? Enough to work with 2 but not 4?

Just wierd how the RAM with the lowest stock fequency and that closely matches what you are actually running it at worked.

I'd guess not, but it's not inconceivable? It's 32GB of Samsung B-die spread over four DIMMs for each set. If you don't enable XMP it doesn't know anything about itself; it doesn't now it's 4400MHz memory running at 3800MHz. I also repeatedly tried running it all at 2133 and no dice whatsoever and surely that should work?

BUDFORCE said:
Zen 2/3 are notorious for being fussy with ram, although most people put lower stock ram and try and overclock it, you are doing the opposite, maybe it doesnt like it either way.

There's space in memory sub-timings and stuff we don't typically see that might cause that. But also there's the CPU factor you mention; so much going on there and all we can be sure about is that the result is a system that's fussy with RAM.

fastboy · 29 Jan 2021 at 15:42

im having a similar issue as the OP

5600x
asus b550tuf mb
rtx tuf 3800

4 sticks of 8gb 4000mhz memory
▷ Patriot Viper Steel 16GB (2x8GB) DDR4 PC4-320… | OcUK (overclockers.co.uk)

it will run at 4000mhz fine with 2 sticks(which has been the last couple of months) but will only post at 3600 with 4 sticks,any higher it wont post,and with 4 sticks i get Dota2 game just randomly closes the game to desktop no warning no errors,its fine with 2 sticks.

ran memtest no issues.

any ideas?

BUDFORCE · 29 Jan 2021 at 16:10

fastboy said:
im having a similar issue as the OP

5600x
asus b550tuf mb
rtx tuf 3800

4 sticks of 8gb 4000mhz memory
▷ Patriot Viper Steel 16GB (2x8GB) DDR4 PC4-320… | OcUK (overclockers.co.uk)

it will run at 4000mhz fine with 2 sticks(which has been the last couple of months) but will only post at 3600 with 4 sticks,any higher it wont post,and with 4 sticks i get Dota2 game just randomly closes the game to desktop no warning no errors,its fine with 2 sticks.

ran memtest no issues.

any ideas?

That's just ryzen mate, 4x 4000mhz is too much for the memory controller.

You might be able to mess around with some settings

BUDFORCE · 29 Jan 2021 at 16:32

Sorry if this sounds like I told you so, but when I put my 5800x build together on a tomahawk x570, I just picked 3600mhz, and 64gb over 2 dimms (2x32) because of Zen 2 being fussy.

They dont like too high frequency even less so over 4 dimms.

Doug2507 · 29 Jan 2021 at 16:34

They should still run at 2133 with everything on auto

philo-sofa · 29 Jan 2021 at 17:10

Probably a coincidence @fastboy, but I've been using patriot vipers too.

Doug2507 said:
They should still run at 2133 with everything on auto

Yeah 2133 should certainly allow us to POST.

fastboy · 29 Jan 2021 at 17:28

what i thought was weird is the lights on the mb were showing cpu error when it wont post above 3600,not ram error.

BUDFORCE · 29 Jan 2021 at 18:22

fastboy said:
what i thought was weird is the lights on the mb were showing cpu error when it wont post above 3600,not ram error.

Yea, it's the memory controller in the CPU.

fastboy · 29 Jan 2021 at 19:22

well damn,waste of money paying extra for fast ram then lol,should have just grabbed some cheap 3600.

tbh wish i had stuck to intel.

philo-sofa · 29 Jan 2021 at 20:57

fastboy said:
well damn,waste of money paying extra for fast ram then lol,should have just grabbed some cheap 3600.

tbh wish i had stuck to intel.

With the new firmware from AMD (AGESA 1.2) you’ll very likely be able to hit 4GHz. It’s comes out end of jan to start of fab. So our 4GHz memory is pretty much perfect.