Lstopo 3900x

[phat_cow]

For my 3900x. Which cores should I be assigning to my gaming vm? I currently have 3-11,15-23 but I think this is wrong since my game (Hunt Showdown) crashes to desktop like ALL the time and when ever there is disk activity my VM stutters. I'm hoping assigning correct CPUs to my VM will fix this.

[phat_cow]

Since the 3900x has 2 Dies (0-5, 12-17 is a die), Should I only assign Cores from a single die to my VM? For example: 2-5, 14-17?

[Decto]

While the 3900X has 2 dies, it has 3 or 4 CCX.

Each CCX communicates with IO die separately so ideally you want to avoid lots of CCX.

I assume you would be able to confim in Ryzen Master.

From the image above, it appears you have 4 CCX of 3C6T.

 

Die 1  CCX 1   0-2,12-14

Die 1  CCX 2  3-5,15-17

Die 2 CCX 1   6-8, 18-20

Die 2 CCX 2  9-11, 21-23

 

Also make sure to install the tips and tweaks plug in and set performance mode for gaming

Edited October 6, 2020 by Decto

[phat_cow]

So, best to do is 3c6t?

[Decto]

2 hours ago, phat_cow said:

So, best to do is 3c6t?

If that is sufficient performance for the VM, then yes use the 1 CCX, otherwise use 2 or 3 complete CCX.

 

Ideally you want to minimise the number of CCX for the number of cores you want to pass.

However the perfomance hit shouldn't be as significant on Zen 2 as on the early threadrippers due to the design changes made where all CCX now connect equally to the IO die. Using cores across CCX shouldn't cause any crashes but may result in stutter or reduced FPS etc.