WD Red Speed differences

[Klontje]

Hello all,

I am burning in my first Freenas build consisting of a Supermicro X11SSH-CTF with a Xeon E3 1245 v6 and 32GB of ECC RAM.

I have 7 WD Red drives installed (WD40EFRX). What I see during testing is a great difference in performance between the disks. I have bought them all from different batches over time to minimize the risk of failure due to a bad batch.

The numbers:

Disk Disk Size MB/sec %ofAvg
------- ---------- ------ ------
da0 3815447MB 146 94
da1 3815447MB 151 97
da2 3815447MB 156 101
da3 3815447MB 156 101
da4 3815447MB 173 112 ++FAST++
da5 3815447MB 152 98
da6 3815447MB 149 96

Disk Bytes Transferred Seconds %ofAvg
------- ----------------- ------- ------
da0 4000787030016 35579 108 --SLOW--
da1 4000787030016 33812 103
da2 4000787030016 32718 99
da3 4000787030016 32742 99
da4 4000787030016 28241 86 ++FAST++
da5 4000787030016 33062 100
da6 4000787030016 34721 105

The serial numbers also show strange patterns (see image), the fastest of them all has a totally different serial number and I am wondering if this is normal.

 

[BigDave]

Yes, everything is happening normally. Just relax and check out the
drives at the end of the testing.

A watched pot never boils...

 

[Stux]

Hello all,

I am burning in my first Freenas build consisting of a Supermicro X11SSH-CTF with a Xeon E3 1245 v6 and 32GB of ECC RAM.

I have 7 WD Red drives installed (WD40EFRX). What I see during testing is a great difference in performance between the disks. I have bought them all from different batches over time to minimize the risk of failure due to a bad batch.

The numbers:

Disk Disk Size MB/sec %ofAvg
------- ---------- ------ ------
da0 3815447MB 146 94
da1 3815447MB 151 97
da2 3815447MB 156 101
da3 3815447MB 156 101
da4 3815447MB 173 112 ++FAST++
da5 3815447MB 152 98
da6 3815447MB 149 96

Disk Bytes Transferred Seconds %ofAvg
------- ----------------- ------- ------
da0 4000787030016 35579 108 --SLOW--
da1 4000787030016 33812 103
da2 4000787030016 32718 99
da3 4000787030016 32742 99
da4 4000787030016 28241 86 ++FAST++
da5 4000787030016 33062 100
da6 4000787030016 34721 105

The serial numbers also show strange patterns (see image), the fastest of them all has a totally different serial number and I am wondering if this is normal.

View attachment 18443

I suspect there are differences in the models. Da7 being a much newer drive and da0 being older.

 

[Arwen]

I agree, the slowest is not really slow.

For your edification: It could also be firmware related. You might want to run
smartctl -a /dev/daX on them all. First, verify model, it's possible you have
Pro model slipped into the bunch. Second firmware.

But, if they are all the same models and firmware revisions, live with it.

 

[Klontje]

Thanks all, testing just finished. The only difference I can find is the ATA version, the fastest disk (da4) has a different ATA version than all the other drives. It's kind of strange because this isn't the newest drive of them all. Does anybody know if this is a hardware revision or something that can be flashed? The firmware is the same on all drives.

One of the other drives:

Code:

=== START OF INFORMATION SECTION ===
Model Family:  Western Digital Red
Device Model:  WDC WD40EFRX-68WT0N0
Serial Number:  WD-WCC4E1NL7D99
LU WWN Device Id: 5 0014ee 20c3acbf7
Firmware Version: 82.00A82
User Capacity:  4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:  512 bytes logical, 4096 bytes physical
Rotation Rate:  5400 rpm
Device is:  In smartctl database [for details use: -P show]
ATA Version is:  ACS-2 (minor revision not indicated)
SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:  Sun May 21 22:08:42 2017 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

The da4 with different ATA version:

Code:

=== START OF INFORMATION SECTION ===
Model Family:  Western Digital Red
Device Model:  WDC WD40EFRX-68N32N0
Serial Number:  WD-WCC7K5ZRZLSE
LU WWN Device Id: 5 0014ee 263df8e3f
Firmware Version: 82.00A82
User Capacity:  4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:  512 bytes logical, 4096 bytes physical
Rotation Rate:  5400 rpm
Form Factor:  3.5 inches
Device is:  In smartctl database [for details use: -P show]
ATA Version is:  ACS-3 T13/2161-D revision 5
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:  Sun May 21 22:13:53 2017 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

 

[Johnnie Black]

Difference in speed is because:

older model: WD40EFRX-68WT0N0 - 4 x 1TB platters
newer model: WD40EFRX-68N32N0 - 3 x 1.33TB platters