Terrible performance with Samsung HD203WI

xvlun · 16. September 2013

hi, i have a performance problem witn a Samsung HD203WI drive in a HP N54L microserver. While all other installed drives perform reasonably my Samsung drive does not. Transfer speed as measured by hdparm (and real life performance copying files from one drive to another internally or via smb to a different computer) is between 300K/s and 10MB/s (from a 2 TB drive!)

I have already moved the drives around to exclude a faulty sata connection but to no avail. Also the drive performs normally when installed in a different PC. Any ideas?

Code

hdparm -tT /dev/sda


/dev/sda:
 Timing cached reads:   2284 MB in  2.00 seconds = 1141.36 MB/sec
 Timing buffered disk reads: 324 MB in  3.00 seconds = 107.85 MB/sec
root@nas:~# hdparm -tT /dev/sdb


/dev/sdb:
 Timing cached reads:   2308 MB in  2.00 seconds = 1153.43 MB/sec
 Timing buffered disk reads: 316 MB in  3.00 seconds = 105.17 MB/sec
root@nas:~# hdparm -tT /dev/sdc


/dev/sdc:
 Timing cached reads:   2110 MB in  2.00 seconds = 1054.86 MB/sec
 Timing buffered disk reads:   2 MB in  7.93 seconds = 258.16 kB/sec
root@nas:~# hdparm -tT /dev/sdd


/dev/sdd:
 Timing cached reads:   2230 MB in  2.00 seconds = 1114.91 MB/sec
 Timing buffered disk reads: 530 MB in  3.01 seconds = 176.07 MB/sec

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davidh2k · 16. September 2013

Sata Cable, defective contact on side of the hard drive...

Would you mind testing with dd against hdparm?

Code

cd /media/UUIDofdevsdc/
dd if=/dev/zero of=tempfile BS=1MB count=1024
dd of=/dev/zero if=tempfile BS=1MB count=1024
rm tempfile

Greetings
David

fizze · 16. September 2013

Are you sure it's not a firmware / cache issue? Did you enable read and write caches on the drive?
Maybe you've enabled SATA features that this drive doesn't handle well? (NCQ...?)
You could try running the same benchmarks off a Live-CD on the same machine to rule out software as a cause.

xvlun · 16. September 2013

thanks for the suggestions:

- faulty sata connections on the server side should be excluded as moving the drive around does not change anything.
- i have not done any specific configuration changes regarding this drive
- the drive (seems) to work fine in a different computer (running ubuntu 12.04)

the dd testing results are really really weird. as writing is much faster than reading, but also the writing speed is not really consistent:

Code

root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# dd of=/dev/zero if=tempfile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 101.057 s, 10.6 MB/s
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# dd if=/dev/zero of=tempfile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 15.4209 s, 69.6 MB/s
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# echo 1 > /proc/sys/vm/drop_caches
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# dd of=/dev/zero if=tempfile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 101.879 s, 10.5 MB/s
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# dd if=/dev/zero of=tempfile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 18.6735 s, 57.5 MB/s
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# echo 1 > /proc/sys/vm/drop_caches
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# dd if=/dev/zero of=tempfile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 10.5829 s, 101 MB/s
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# echo 1 > /proc/sys/vm/drop_caches
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593# dd of=/dev/zero if=tempfile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 100.737 s, 10.7 MB/s
root@nas:/media/8c2c46de-7bc6-4080-b109-e2c860e77593#

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davidh2k · 16. September 2013

Please try:

Code

cd /media/UUIDofdevsdc/
dd if=/dev/zero of=tempfile BS=1MB count=30720
dd of=/dev/zero if=tempfile BS=1MB count=30720
rm tempfile

And check if this gives a more consistent speed. I just limited then benchmark before to 1GB because I thought even that would take hours with only kb/s performance....

Greetings
David

PS: You confused read and write. You read speeds are higher than your write speeds.

xvlun · 16. September 2013

Zitat von "davidh2k"

PS: You confused read and write. You read speeds are higher than your write speeds.

this is read speed, is it not? anyway.
I did some further testing. And the issue is not software related (as ubuntu 12.04 live shows the same behaviour on the hp n54l). I will put the hdd in a different pc now and try again, if this really makes a differences (as stated above).

davidh2k · 16. September 2013

Nevermind, I'm was just confused by your output...

Well, I would try around as best as I can if I would like to found the root of the problem

Greetings
David

xvlun · 16. September 2013

different computer: no problem at all.

Code

dd if=/dev/zero of=/media/jan/SS2TB/tempfile bs=1M count=2048 
2048+0 records in
2048+0 records out
2147483648 bytes (2,1 GB) copied, 19,4719 s, 110 MB/s
val jan # echo 1 >/proc/sys/vm/drop_caches
val jan # dd of=/dev/zero if=/media/jan/SS2TB/tempfile bs=1M count=2048 
2048+0 records in
2048+0 records out
2147483648 bytes (2,1 GB) copied, 20,725 s, 104 MB/s

I also tried to update the firmware of the hdd as I read sth about Problems of the samsung spinpoint F3 drives in combination with the AMD SB 850 chipset but again to no avail. (HP N54L seems to have the AMD RS785E/SB820M, but i tried anyway)

I give up. I'll buy a new drive

davidh2k · 16. September 2013

Zitat von "xvlun"

[...]

I give up. I'll buy a new drive

Sorry that we can't figure it out. I would recommend a WD Red as a new drive.

Greetings
David

PhantomSens · 17. September 2013

There is one other area to look at is the power supply. HP usually makes good things, though if it is getting weak or is at it's limits it could be the problem.

Like Davidh2k I too prefer WD drives and their Reds for NAS data use.

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