Hi,

 

I had a mini pc with an AMD 7840hs (Beelink GTR7 pro - 8core-16threads, 32GB ram) running unraid using an external disk enclosure (terramaster d6-320) over USB-C.

With 3 x 20TB drives in it and an internal 1TB NVMe drive in the mini pc.  The Terramaster box supports 10gbit/s speeds over usb, the type-c ports of the beelink are USB4 I believe. I get about a constant 230MB/s speed when doing a parity check. It was running great.

 

Originally I was planning on using this unraid box also for VMs, but since I rarely run VMs after all, I wanted to re-use the mini pc as a workstation as it's pretty beefy, and use something more low-power (and low-cost) as my unraid box. 

 

I bought a second hand HP ELITEDESK 800 G4 (8GB DDR4  Intel i5-8500T 6-CORE ), specifically as it has an type-c usb port, which is usb 3.1 Gen2 and should support 10Gbit/s.

 

I struggled a bit to get the box booting unraid over usb, but eventually it boots unraid reliably. 

As a test however, I did a parity check, and the speeds I see are really erratic (and disappointing)

At some times I see speeds up to 180MB/s, but then suddenly the speed drops to 7MB/s, or 50MB/s, a few moments later to 20MB/s.

 

I was expecting the speeds not to take a hit since the storage box supports 10Gbit/s, as should the usb port on the HP box.

Am I missing something here?

 

I checked the speeds using lsusb --tree and the link speed is actually 10Gbit/s.

(           |__ Port 2: Dev 6, If 0, Class=Mass Storage, Driver=usb-storage, 10000M)

 

Am I missing something? Is the usb link limited in some way? Or can the speed be affected by the smaller ram or slower CPU (and fewer core count?)?

The cpu utilization hovers around 50% and memory around 42% (all docker container disabled) during a parity check when I notice about 80MB/s. But like I said, the performance is very erratic. Should I up the ram?

 

Any insights would be appreciated.

 

Best regards,

Jan

 

 

 

 

USB not recommended for array or pools for many reasons.