Slows 235MB's - Copying from external usb3.1 NVMe SSD to internal cache drive also NVMe (gen4)

[dopeytree]

Copying from usb3 external NVMe ssd to cache drive NVMe so why is it so slow?

 

Is there a problem with speed if you use a cache pool mirror?

I have 1x gen4 NVMe & 1x gen3 NVMe on the motherboard as a cache pool - so the gen4 is mirrored to the gen3.

 

When I use diskspeed test docker both SSD drives are around 2300MB/s.

 

It shouldn't be touching the array disks. The share is set to use Cache. But anyway I am copying direct to cache rather than the user share.

 

The array drives test around 240MB/s down to 108MB/s.

 

 

My understanding is USB 3 provides up to 500MB/s read & write. ( Dependent upon encoding overhead )

 

And USB 3.1 up to 1200 MB/s read & write. ( Dependent upon encoding overhead )

 

Edited September 22, 2022 by dopeytree

[Vr2Io]

14 hours ago, dopeytree said:

My understanding is USB 3 provides up to 500MB/s read & write. ( Dependent upon encoding overhead )

First ver. actual throughput will be 300MB/s and I am not sure Unraid support newer version or not even you have 3.2 gen 2 controller & device.

[dopeytree]

Most online benchmarks put usb3 real throughput at around 400MB/s.

 

Have noticed USBc port doesn't work out the box with unraid. USB3.2 gen1 works tho.

 

Anyway even internally avoiding USB & Sata seem to get slow copy's even just NVMe to NVMe.. any ideas I should explore?

[dopeytree]

Update - fixed this slow copy issue by installing the Auto Turbo Write Plugin!!! Everything is now insanely fast.