I've noticed similar behavior. Do me a favor and try to switch to gaming mode in Ryzen Master (disabling the other CCX) and see if the problem goes away.
If it does --- switch to creator and disable SMT.
The Problem should still be there but to a lesser level.
For me it looks like a generic problem of the Threadripper platform --- it appears on my ASRock X399 Fatal1ty Pro Gaming with the latest BIOS (also on the very latest Beta L.1.61 BIOS)... I presume it is somehow related to PCIe saturation.
Memory OC stability is also lower than on the X370 platform (4x 16GB Ripjaws V, 3200 CL14) --> on X370 it runs full speed, on X399 max stable is 2933.
It might somehow be related to this Windows 10 issue described on stackoverflow:
If you run Windows 10 that is...
I also have the same issue, 3 months later and it doesnt seem like AMD has fixed this issue.
The lag is gone (or minimized) after upgrading to 1709. Just use the newest chipset drivers and upgrade.
Seems it is not AMDs fault.
New installation and completely unplayable due to issues when moving the mouse.
On menus or anything else where the mouse is a pointer, slow movements will work for a short while, and then fast movements will cause the pointer to freeze for up to several seconds before jumping to the new position.
In Google Browser or any other Browser just surfing the internet with 1 or 20 Tabs open response to mouse movements is severely lagged .
I've check the internet but nothing about this issue.
I done Bios Upgrade, NVM Upgrade all drives to the lasted upgrade.
Memtest86 all 4 passed i took a picture but didnt save on my phone.
Please check the following pictures and let me know what i need to do next. Thank You!