[SOLVED] System will work with 1, 2, and 3 sticks of RAM, but not 4

[GG_Sumo]

I once bought a 32 GB (4 x 8 GB, DDR4, CAS Latency is 18) kit of Corsair Vengeance RGB memory and it used to work well. After a while, my PC crashed and I couldn't boot it up with more than 3 sticks anymore. I've been able to get the system to boot to the BIOS with the 4 sticks (unstable), but not any farther. I know that every stick and DIMM slot works, I've tried overclocking, and I have changed both my CPU (2700X -> 5900X) and motherboard (to no avail). Before my computer had that crash, I did change the (Corsair RM 750) power supply's cables with a CableMod kit, so this could be the cause (although I'm not sure). Is this a problem that any of you have a possible solution for?

 

[RealBeast]

Have you tried resetting the CMOS and then go back in and set your bios setting again? I've used this to fix many similar issues.

 

[GG_Sumo]

Have you tried resetting the CMOS and then go back in and set your bios setting again? I've used this to fix many similar issues.

That sadly hasn't worked either, but thank you for the advice!

 

[RealBeast]

Test your cable mod outputs with a multi-meter, and if all is well I would try bumping Vdimm up to 1.4V.

 

[GG_Sumo]

Test your cable mod outputs with a multi-meter, and if all is well I would try bumping Vdimm up to 1.4V.

I just tested the cables and they seem to work fine. Bumping the Vdimm up to 1.4V sadly didn't help. I tried turning off the RGB on the RAM sticks to see if it would help and I was able to get to Windows, but the system crashed right after that.

 

[RealBeast]

So by the cables work fine, I assume that you mean they are all very close to the spec voltages.
Take a quick look through the memory troubleshooting guide, although much is not relevant for you.
For some reason, the most common memory issues that I see with AMD are in Corsair Vengeance RGB, maybe just its popularity but it seems odd.

 

[DimkaTsv]

Corsair Vengeance RGB

Well.. one thing i noticed not so long ago, when tried to solved a bit similar problem, that Corsair Vengeance 8GB sticks (i have set of 2x8 3200 cl16) is surprisingly double-ranked . Which is actually... not quite nice for filling 4x slots with them. Maybe RGB ones aren't though, idk
Ryzen works good with 2x ranks, better with 4x ranks. may require downclocking RAM for 6x ranks (well.. maybe my I/O die on 5600x is just trash, as it also cannot run more than 1800 FCLK... Maybe it can run 1833 or 1866 but for sure fails miserably at 1900+). But i don't recall any mentions that it can actually run well with 8x ranks without some severe RAM underclocking.

So my recommendation is check with Zen timings if these sticks single ranked or double ranked . Because if they are double ranked, you may have just put yourself in 8x rank trap and need underclock

Spoiler: Where to look

P.S. Yeah, for anyome who noticed. That 4000 C19 in example was so overkill (actually not much expected one), that i cannot even run it with benefit without manual timings, because both XMP can only be used in gear down mode which doesn't make it much better than what i have now. Felt like wasted 35% of cost... At least it can run same timings as my old overclocked RAM. Also it good for all kinds of examples