Slow M.2 drives (file transfer)

[egor999]

Hello all!

 

I've just put together a new machine with dual m.2 2TB Samsung 980 Pros and have noticed the transfer speeds between the two drives to be much slower than they should be. Transferring files between the two drives via a Windows VM and the unBALANCE plugin produce nearly identical results of a transfer rate of approximately 700-800 MB/s. 

 

Benchmarking the drives via the DiskSpeed docker container puts the read on both drives at around 4.1 GB/s (which is still slower than advertised but much better). Crystal disk mark running in above said Windows VM puts the drives read/write performance at roughly advertised speeds (again, the VM still transfers slow between the drives despite the great benchmarks).

 

I've never loaded windows on this machine so I don't have a comparison there. I booted Ubuntu from a USB stick earlier today and transfered a large file between the two drives at 2.1 GB/s sustained which tells me there's something going on in Unraid, either with my config or is a more fundamental problem with Unraid itself. The drives are used as typical array drives, not as parity or cache.

 

Here's my machine specs:
5950x
Asus proart x570

16 gigs of ram (128 gigs to arrive soon)
2x m.2 2TB Samsung 980 pros

2x 2TB Samsung 960 pros

Unraid 6.9.2

All drives have XFS files systems

 

Any help would be appreciated!

[trurl]

1 hour ago, egor999 said:

drives are used as typical array drives, not as parity or cache.

Do you have a parity drive? 

 

Also note that array drives can't be trimmed. 

[egor999]

Great clarification question - I don't have a parity drive.

 

Interesting, I wouldn't expect array drives to be excluded from trim but I guess that is what it is.

[egor999]

If it helps - attached is my syslog. Any advice on configuration or something which could be causing this would be super appreciated.

syslog.txt