Gigabyte B550 Aorus Pro AC instability with (4x8gb) 3600mhz XMP

[OsMoFF]

Hi Everyone.

 

My pc specs:

CPU: AMD Ryzen 5600X

Motherboard: Gigabyte B550 Aorus Pro AC with latest bios update (F13J - 23 April 2021).

Ram kit1: Corsair Vengence RGB Pro (CMW16GX4M2Z3600C18) 16gb 2x8GB

Ram kit2: Corsair Vengence RGB Pro (CMW16GX4M2Z3600C18) 16gb 2x8GB

 

The issue:

I have x2 dual kits installed in all 4 slots. Currently the RAM is running at 2666Mhz and stable. When I enable XMP to boost to 3600Mhz the system is unstable (cannot even log into windows).

 

How I have tested:

Method 1: Used each ram kit separately (2x8gb) in slots DDR4_A2 & DDR4_B2 with XMP enabled and system boots fine with no issues. But using both kits at the same time system only runs with XMP disabled.

 

Method 2: Used the same scenario as above in my friends Asus ROG X570 Dark Hero motherboard and AMD Ryzen 5900X CPU. Using both ram kits (4x 8GB) with XMP enabled causes instability. Both kits running (2x8Gb) with XMP enabled works fine.

 

The kit (CMW16GX4M2Z3600C18) was listed on Gigabyte QVL as supported memory socket 2, but not 4. So could this be that because its two dual kits that it cannot be used in all 4 sockets together?

 

All settings in Bios is running on AUTO. Enabling XMP causes the instability when using all 4 ram sockets.

 

Thanks for the read.

 

Regards

OsMoFF

Edited May 23, 2021 by OsMoFF

[Infin1tum]

check the Ver. numbers on the back of the sticks. You most likely have different ICs on them.

[OsMoFF]

check the Ver. numbers on the back of the sticks. You most likely have different ICs on them.

 

Thanks for the reply. I checked the modules now. Both kits (all 4 modules) are version 8.31.

[Corsair Fer]

Even with same SKU/version number the system may not be stable when installing two different kits into the system.

 

From your comment regarding only installing the kits in their proper pairings and the system being fine then this is the case.

[Infin1tum]

If all sticks have the same ICs and are all in working order, your CPU/Mobo combination is simply incapable of running this configuration (which is kinda surprising to me for the Dark Hero, but I don't know that much about RAM OC on Ryzen)

If you still want to run with 4x8 you basically have 3 options:

1. increase you VSOC an/or VDRAM voltage, see if that works

2. lower your RAM frequency

3. loosen your timings

 

if none of these work for you or you don't feel comfortable messing with these things, you gotta get a different kit. Personally, I always prefer 2x16GB over 4x8GB.

[OsMoFF]

Even with same SKU/version number the system may not be stable when installing two different kits into the system.

 

From your comment regarding only installing the kits in their proper pairings and the system being fine then this is the case.

 

That is also my hunch at the moment. I am trying to see if it would be possible to swap out the kits at the supplier.

 

Would your suggestion be to get a quad kit (4x8gb) 3600mhz?

 

I was looking at the best plug and play solution with RGB at the time of purchase that I could find stock of.

[LeDoyen]

for Zen3, it's slightly better to run 4 sticks, so if you can return the bunch and get a 4x8gb kit, that would work out good, as long as it's in the QVL.

 

If not you can still get a 2x16 plus two dummy sticks if you want the looks :p

[OsMoFF]

for Zen3, it's slightly better to run 4 sticks, so if you can return the bunch and get a 4x8gb kit, that would work out good, as long as it's in the QVL.

 

If not you can still get a 2x16 plus two dummy sticks if you want the looks :p

 

That's also how I understood it when I planned my build, get 4 sticks because it apparently has a performance increase.

 

Yes, 2x16gb with dummies is last resort. :biggrin:

[Infin1tum]

It's always and will remain always better to try and get the fewest modules in the largest quantities provided that the few modules result in the same channel and rank counts.

 

The often reduced frequencies/timings for larger modules mostly match up with the caveats of running twice as many smaller modules, the primary benefit though is that it's far easier to add memory to the system after the fact vs having populated them all already and having to essentially replace them all to make any further improvements.

 

So if all modules are identical speeds/latencies, and since most 16GB modules are dual rank vs the 8GB modules being single, then running 2x16GB is a superior and clearly better option than running 4x8GB

 

tl;dr: 2x16GB > 4x8GB

[LeDoyen]

If indeed running two dual rank yields the same results as 4 single on Zen3, running two dual should be better on your particular motherboard since it uses daisy chain tolopogy. This is usually best suited for one stick per channel