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Need a little Help Improving my X399 Build


I built a quick X399 build when I got the 1950X on a super sale. I had some spare parts laying around, and a bunch of sales over time. Now I would like to get it to being my main development PC.

Issues I am having is the ram is not clocking to 2666. I figure this is because I have 2 different brands. Because I have 2 different brands can I get them both clocked to 2666? I am thinking of buying a kit that is 128Gb 8 sticks of 16gb is this a good idea? I read somewhere that maxing out the DIMM slots is not the best thing to do performance wise, is this correct?

I would like to upgrade the graphics card. I want to give linux a go, what would be the best fit there? I also would like to do KVM passthrough. I figure the Radeon 580 or 590 would be good. I mostly RDP into this box right now is this possible with linux without VNC?


Threadripper 1950X

Cooler Master MA621P TR4 Twin Tower RGB CPU Air Cooler, 6 CDC Heatpipes, Dual 120mm RGB MasterFan, AMD TR4 Support

Prime X399-A Rev 1


  1. XPG 32GB (2 x 16GB) 288-Pin DDR4 SDRAM DDR4 3000 (PC4 24000) Desktop Memory Model AX4U3000316G16-DRG
  2. Patriot 2666 C16 Series 2x16gb

WD Black 512GB Performance SSD - M.2 2280 PCIe NVMe Solid State Drive - WDS512G1X0C

2 120gb patriot burst

512gb crucial - I think its the 200mx - might be older

2 3tb 7200 rpm

AMD Radeon R9 280 3gb

CORSAIR RMx Series RM850x CP-9020180-NA 850W ATX12V / EPS12V 80 PLUS GOLD Certified Full Modular Power Supply

Thanks for any help


Go nvidia… I have many reasons for this… mainly the reset issues with the AMD graphics cards and the 590 cant be used on linux just yet without severe performance regressions… its getting there… I would opt for RTX 2060 or 2070

MMM okay you have a Prime X399 Lets try to get them down to that manually … JEDEC standards are below

Standard Memory I/O bus Data Module Peak trans- Timings CAS
name clock clock rate name fer rate CL-tRCD-tRP latency
(MHz) (MHz) (MT/s) (MB/s) (ns)
DDR4-2666T 333.33 1333.33 2666.67 PC4-21333 21333.33 17-17-17 12.75
DDR4-2666U 18-18-18 13.50
DDR4-2666V 19-19-19 14.25
DDR4-2666W 20-20-20 15

Lets try for the T timings… set them manually you should be good. Attempt to set the timings as close to them as possible dont forget the multipliers LOL which is basically 8* memory base clock… But yeah try to use those timings and set to 2666

If that doesnt work we will look at ram


So I think I got my ram at 2666 Just set it to 2666 in the bios when looking at CPU-Z I see this.


I check the individual channels
The patriot says 1066, is it running at 2133 or because I set in the bios 2666 it is actually running 2666?




For hasslefree experience on linux and vfio the GPUs to go to are AMD Polaris cards.
You need to do a research which models dont suffer reset bug but thats it.
Only exception is RX 590 as it is not well supported yet.

If you want more performance than RX 580 or CUDA you should go nVidia.
For nVidia you should look for distro with good support for their proprietary driver.
Still be prepared to suffer some restrictions and regressions on both the linux and vfio side.

As for RAM, look at the articles here on L1. @wendell did test at least one 128GB kit and was happy with it.
IIRC it was g.skill kit.


I watched the 128gb for threadripper. He used a G-Skill set that I can’t seem to find it. I found what seems like a really good deal for GSkill Flare X 2400 128gb set would that be ok or do I really need 2666 or faster?