Sustaining 10gb network write to cache over large transfers?

[dynamis_dk]

Hi guys, I've not had much need to come back to the forums for a while as everything has been purring away just nicely but it was time to make a change so I'm seeking advise once again.

 

I've got a ASRock Z97 Extreme4 motherboard which gives me a M.2 PCIe Gen2 x2 slot to work with so I've got a Samsung PM961 M.2 2 256GB drive to play with. I've installed the drive in the motherboard, unraid has detected it fine and I've installed Unassigned Drives so I could present it as a share for a few file copies to see how it performs. I'm happy with the write speed as I believe I'm hitting what I should expect from Gen2 x2 but the write speed tapers off after about 8gb of write.

 

I've tested the disk with jbartlett777/diskspeed to get a ball park of the performance and it shows a write at about 800mb from start to finish so I'm trying to get an idea of why the write performance drops to 120mb after about 8gb of transfer. Given this is a unassigned drive I wouldn't expect to take any write hit like you would writing to the array so can someone pitch in and give me some thoughts of where to resolve this? Eventually I'd like to move to a 512 or 1tb SDD cache so I can take advantage of the 10gb networking and also give a little spring in the step of my VM's.

 

Is it the SSD thats the issue (age, memory type etc) or something more fundamental behind the scenes?

 

Cheers guys

[testdasi]

What is the source of your copy?

[dynamis_dk]

Windows 10 drag and drop as its my main workstation.

 

Is there an alternative copy method which maybe worth a look if that might be my bottleneck? Robocopy, teracopy?