threadripper 3990x woes (ASUS Mobos)

[theskaz]

I just wanted to put this here, for someone that might be googling for this issue/idea.

 

Asus has 3 motherboards that I have gone through for my 3990x processor:

Asus Prime-Pro

Asus Zenith II Extreme

Asus Zentih II Extreme Alpha

 

On the Asus Prime-Pro board, there is an asterisk on the box saying that on a 3990x it will only run RAM at 2666MHz. If you think you can bump that up at all by overclocking or anything, you are wrong. you are stuck at 2666MHz period. end of story.

 

On the Asus Zenith II Extreme, it does not have that asterisk. As a matter of fact there are some people out there who thinks this board is perfectly fine for the 3990x. Not quite. With my 3990x I bough 256GB DDR4 3200MHz GSkill Trident Neo Ram Modules. I was told that this kit was for the 3990x. I popped them all in, and booted unraid. I did not enable DOCP/XMP

 

Then unraid crashed. after some troubleshooting, I found that the RAM was causing it. So i ran 4 sticks at a time through memtest86 for a few days on a different mobo. 0 errors. I then tried running all 8 sticks through memtest on the zenith II Extreme and I noticed that only 192GB showed up. ok, I have a couple sticks that werent seated or something. I then rearranged as many ways as I could to rule it out and it always came back to 192 GB. I then tried to boot with just 4 sticks and it worked perfectly at 2666MHz.

 

on a side note, enabling DOCP caused the mobo to keep rebooting until it went into safe mode. Didnt matter how many sticks I had. 

 

Now I am on the Alpha. it shows 256GB RAM @3200MHz. no issues at all.

 

So, if you have a 3990x and want an ASUS board, get the Alpha.