Slooow copying to internal RAID 0 drive

[VelcroFace]

I recently installed 2 Seagate 8TB Enterprise drives on my ASUS P9X79 Pro system, and configured them as a striped 16TB volume (RAID 0) through Windows 10 Disk Management. AJA System Test measured the write speed as 334 MB/sec for a 4K video file 4GB in size. However, whenever I copy a file onto this drive from one of my other data drives (WD Black 1TB), the speed drops to less than 20 MB/sec. What might be causing such abysmal write speeds?

 

[anonymousdude]

Is the WD an internal or external drive? \
Is the file you're copying over one large file or a folder full of files?
How full is the WD drive?
My instinct tells me that the drive is pretty full and that it might be fragmented so the speeds are pretty slow. Seeing 20 MB/s isn't surprising if the drive is fragmented and full. And you can't write faster than you can read.

 

[SuperSoph_WD]

Hey there, @VelcroFace!

Could please provide more details about the troubleshooting you have done so far? It's also important to know how big are the files that you are copying from the WD Black onto the RAID 0 array. It might be a good idea to test the speeds while copying from the RAID 0 onto the WD Black again. Have you run any HDD diagnostics recently? I'd suggest you check what is health and SMART status of the data drive by running the QUICK and EXTENDED tests from the WD Data LifeGuard Diagnostics for Windows. However, make sure you backup all your data from the WD Black and the RAID 0 somewhere off-site before you proceed with the troubleshooting! Another thing that comes to mind, besides what @anonymousdude mentioned is checking the connections to the drives and even try swapping the SATA ports and the SATA cables to see if it would improve the transfer rate.

Hope it helps. Keep us posted.
SuperSoph_WD

 

[VelcroFace]

Thanks for the suggestions and advice. After conducting more tests, it appears that the issue occurs only when I copy files to or from OneDrive folders on my desktop. Perhaps OneDrive throttles all copy processes, or maybe there is some overhead where OneDrive folders are concerned. Whenever I copy a file that is not in OneDrive folder, the speed averages 112 MB/sec. CrystalDiskMark reports a read speed of 340 MB/sec. for the RAID 0 array, so it appears to be operating as it should.