Very slow read speeds - Functionality Issues

RE: Very slow read speeds

SoftRAID Support — Sun, 13 Nov 2022 01:58:24 +0000

@mjsanders400

Not a red herring, you have proven it is not a SoftRAID issue.

This is unusual. Just to be sure, try this:

Create a RAID 0 volume with 4 drives, ABCD, then BCDE. Is performance OK with both configurations? (this eliminates one disk/slot being the cause)

If you create a 5 disk mirror, what are the read speeds then?

Hopefully this is not an enclosure issue.

RE: Very slow read speeds

mjsanders400 — Sat, 12 Nov 2022 18:26:30 +0000

@softraid-support So I tried switching cables and got the same results. 5 drives slow, 4 drives fine - and it doesn’t appear to matter which 4 drives.

I tested each drive/bay by formatting in disk utility and running speed test - each 2TB drive gave me about 230MB/s r/w and the 4Tb a r/w of 180MB/s.

Not sure if this is a red herring but if create a RAID zero in disk utility I get a write of 630MB/s and 40MB/s read - in either a 4 or 5 drive configuration.

RE: Very slow read speeds

SoftRAID Support — Sat, 12 Nov 2022 17:15:40 +0000

@mjsanders400

This is very strange.

You need to try a new cable. This appears to be a bad cable, bad enclosure or bad disk.

Cables are cheap, so lets try this next.

RE: Very slow read speeds

mjsanders400 — Sat, 12 Nov 2022 09:53:16 +0000

@softraid-support Here you go..

This is with the RAID configured as a RAID 4, with all five drives selected, with the 4TB in bay 5 as the parity disk.

1756 1757

RE: Very slow read speeds

SoftRAID Support — Fri, 11 Nov 2022 23:24:26 +0000

@mjsanders400

Let me see a support file taken when you are getting 40MB/s writes.

RE: Very slow read speeds

mjsanders400 — Fri, 11 Nov 2022 17:48:40 +0000

So with 4 x 2 TB drives configured as RAID 4 I'm getting much better performance. If I add a 5th drive to the mix it falls over. And it doesn't seem to matter which 4 drives I use. I currently have bay's 1 - 4 with 2TB Seagate Barracudas and Bay 5 with a 4TB barracuda but performance is fine if I use 3 x 2Tb and 1 x 4TB or 4 x 2TB.

Any ideas?

1752 1753

RE: Very slow read speeds

mjsanders400 — Fri, 11 Nov 2022 17:40:41 +0000

1750

Here you go.. Here's with 5 disks configured as RAID 5, and then 5 disks as RAID 4. Just about to reconfigure it as a RAID 4 with 4 drives

RE: Very slow read speeds

SoftRAID Support — Thu, 10 Nov 2022 16:34:11 +0000

36MB/s?

Please save a SoftRAID tech support file and attach it.

Very slow read speeds

mjsanders400 — Thu, 10 Nov 2022 10:22:16 +0000

I'm using Softraid 7 with a 16" M1 MacBook Pro and Oyen Mobius Pro 5C enclosure. Three of the bays have Seagate Barracudas and two have IronWolf pro's. I've speed tested each bay with Aja Speed Test and each is easily over 150MB/Sec read and write.

However when I create a RAID 5 array with all five discs, the read speed of the array falls to 36MB/sec.

Any ideas why?

I've deleted and reinstalled Softraid and rebuilt the raid but still no joy.