Slow performance 1920x Threadripper (SMT enabled and only 12 threads visible)

[bartosh44]

On some 3d apps it is very slow (slower than my old quad notebook). That app is multithreaded and using all possible threads.

When I enable SMT on Ryzen Master then I see only 12 cores and 12 threads.
When I disable SMT on Ryzen Master then I can see 12 cores and 24 threads.

On memory benchmark it shows half of performance.

I`ve disabled HPET. I`ve reinstalled new Win10 Pro. I`ve installed all newest drivers and BIOS.

Is it becouse I have only dual ram not a quad one?
Is it faulty CPU/RAM/motherboard (it`s brand new comp)?

How to turn on all threads with enabled SMT(hyper threading)?

Please help me to find solution becouse I have to work on it soon and I can`t do my stuff.
Any help would be greatly appreciated.


My system:
Motherboard: x399 sli plus (AMI BIOS Version 7B09vA6 A.6.0 2018/08/09, AMD Chipset Driver Version 17.40.2815.1010)
Video: GTX 1080Ti
CPU: 1920x (Ryzen Master 1.4.0.0728)
SSD Samsung 860 PRO EVO
CPU cooler: NH-U14S TR4-SP3 (temperature up to 50 celcius)
RAM: Kingston Fury 64GB (4 x 16GB) DDR4 2400CL15
Windows 10 Pro version 1803

 

[jusuandre]

Did you check about MB and RAM compatibility? I doubt it's tho. Did you try to switch to Creator Mode? Game mode disable half of your cores.

 

[bartosh44]

Thanks a lot jusuandre for trying to help.

RAM is present on QVL of this motherboard.

On Game Mode with enabled SMT I can see 6 cores and 6 threads.
On Creator Mode with enabled SMT I can see 12 cores and 12 threads
On Creator Mode with disabled SMT I can see 12 cores and 24 threads

Maybe that motherboard do not support SMT feature? If that is true then why Creator Mode with disabled SMT shows 24 threads.

Other idea is that dual channel instead of quad channel disabled that CPU feature and I should buy more RAM to fill all slots.

I don`t understand it. I`ve checked RAM with tests and all is ok.

Or maybe something is faulty.

 

[bartosh44]

I have one more strange behavior.

When I disable SMT in BIOS and I have disabled SMT in Ryzen Master (Creator Mode) then I can still see 12 cores and 24 threads (same way as I had SMT enabled in BIOS).

When I disable SMT in BIOS and I have enabled SMT in Ryzen Master (Creator Mode) then I can still see 12 cores and 12 threads (same way as I had SMT enabled in BIOS).

So it looks like SMT feature is not supported on my MoBo (but there is present option in BIOS - SMT auto and disable). Maybe BIOS is same for all models and higher version will support it properly or my unit is faulty.

So in Windows and Ryzen Master settings all looks same with no connection is that SMT option is disabled in BIOS or not. Performance is also same (maybe even 3% faster if disable SMT in BIOS for both cases in Ryzen Master).

Maybe If I buy top class MoBo then SMT feature will show 24 threads.

Please help me to identify reason of this issue.

 

[jusuandre]

Well with SMT on it's combing up 2 threads for better performance, so it would be a normal behavior that with SMT ON you only see half of the threads. You actually don't lose but gain in performance in single core bench's. I think everything works as indeed and you should not worry. You should let in ON if you don't intend to OC your CPU. It should help all-around performance.

 

[bartosh44]

In my case in cinebench enabled SMT in Ryzen Master is about 60% of disabled SMT in Ryzen Master and there is no difference if I disable it permamently in BIOS.

 

[jusuandre]

I don't understand what you want to say?