NVMe Installed in DIMM.2_1 - Slow speeds

[Haans249]

Hello All,

Been trying to figure out my updated storage setup. I have a HP EX920 1TB installed in the DIMM.2_1 slot and an Intel Optane module installed in the M.2_1 slot accelerating my 6TB secondary spinner. I have successfully got my Optane module working and am booting properly into the 1TB NVMe drive. *I am NOT attempting to accelerate my NVMe SSD with the Optane module.

* However, running CrystalDisk shows that my speeds for the 1TB drive is underwhelming. My read speeds are ~1500mb/s instead of the ~3100mb/s read speed. I have the source for DIMM_2.1 set to PCH and tried to switch it to CPU in BIOS (since I have no U.2 or Dimm.2_2 installed), but windows fails to boot. PCIX8 is set to Auto. I have Intel RST (RAID) instead of AHCI set to properly manage the Intel Optane module.

What am I missing? Any suggestions?

Thanks a lot.

[JustinThyme]

If you are using an optane memory module to cache an SSD go to a mirror and repeat this over and over

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Optane memory modules are accelerators meant for spinners to get them closer to SSD performance. They will slow down every SSD there is and cease to show any improvement on spinners once the cache is saturated.

[Haans249]

If you are using an optane memory module to cache an SSD go to a mirror and repeat this over and over

I
M
We
Tall
Did

Optane memory modules are accelerators meant for spinners to get them closer to SSD performance. They will slow down every SSD there is and cease to show any improvement on spinners once the cache is saturated.

Sorry for my confusion. I am not acclerating my NVMe SSD with the Optane. My optane is accelerating my 6TB secondary drive. I stated my current config (m.2 installed into two locations) incase it makes a difference. I’ll update my post.*

[JustinThyme]

Yes makes a difference. Now what drive is giving sub par performance? Is the speed you are referring to as subpar the spinner with the Optane cache?

Help can be better provided with specifics
All system specs
Bench runs of both drives with and without the Optane stick.

[Brighttail]

Also remember that it make take a few runs of programs and such for the Optane to get used to your usage on the Spinner drive.

[Haans249]

Yes makes a difference. Now what drive is giving sub par performance? Is the speed you are referring to as subpar the spinner with the Optane cache?

Help can be better provided with specifics
All system specs
Bench runs of both drives with and without the Optane stick.

I understand my first post was confusing prior to my edits. But, I clearly stated that the speed test was on the NVMe 1TB drive. I have no concerns re: Optane. I simply mentioned it because it is another item installed using PCIe lanes.

System specs; R6E, 7940X, a single 1080Ti.

1TB NVMe is installed in the DIMM.2-1 slot with source PCH set in BIOS. This is my boot drive.
Optane installed in M.2-1 slot accelerating my 6TB spinner. *PCH set to Intel RST (Raid) for proper function of Optane. *

I’m not sire what else you need to know. Windows 10 version 1709. All standard setup.

Thank you**

[JustinThyme]

Couldn't have been too clear if it wasn't understood. I wasnt the context of the post as much as the bouncing information.


If you have DIMM.2_1 set to PCH then its sharing bandwidth with the optane stick on the DMI bus. meaning 2 4X devices sharing 4X bus to the CPU. Set it to CPU instead and make sure all PCIE devices are set to GEN 3 instead of auto and nothing in the bottom PCIE slot and you will be golden. The statement given about 24 lanes on the PCH is misleading. Sure there are 24 lanes BUT and its a HUGE BUT those are all downstream of the PCH and the PCH connects via the DMI bus to the CPU on 4 Lanes hence the term bottle neck. Same reason why its useless to run raid0 on NVME drives downstream. They are already at or very close to the total bandwidth of the DMI bus. Everything else is downstream too. USB ports. sound etc.

This isnt the exact diagram but add in DIMM.2_2 always on the PCH and a switch on DIMM2.1 putting it down the same lanes with PCIEx16_4 or on the PCH.

[Haans249]

That is helpful informtaion.*

I have switch the DIMM.2-1 to CPU for source and Windows 10 will no longer boot. I also moved the drive to DIMM.2-2 and still wont boot. The only way the drive boots is if BIOS is set to PCH for DIMM.2-1 with NVMe installed in DIMM.2-1.

When i got the NVMe drive, i did a copy of the original Windows 10 SSD to the NVMe and removed the original SSD. Is there a way to save my original i stallation or will I need to completely reinstall windows?

Thank you*