What SATA transfer speeds can I expect in Linux?

TheBigCheese · 15 Oct 2012 at 18:51

Hi mateys

I'm using the latest version of Ubuntu which I downloaded last night to copy data from one drive to another via SATA.

Currently it's transferring around 40MB/Sec, Windows usually gives me anything up to around 90-100MB/Sec so I'm waiting around quite a bit.

Is this usual with Linux or can something be tweaked to improve the speed?

Thanks!

KIA · 15 Oct 2012 at 19:45

It should be able to match the Windows transfer speed.

Which drives and controller are you using?

You could use the Ubuntu drive benchmark utility.

TheBigCheese · 15 Oct 2012 at 21:34

Thanks for the reply! Good to know that the speeds should be the same.

I've run benchmarks on both drives and they are averaging at about 80MB/s for read speed, unfortunately I couldn't test write speeds as the drives need to be empty apparently.

I'm copying from a Samsung HD103UJ 1TB to a Western Digital 7500AAKS.

I think it might be me rather than Ubuntu actually...I seem to have them both plugged into PATA controllers set in IDE mode.

I can see SATA controllers but they aren't into that...I'm guessing that could be the problem?

melvis · 16 Oct 2012 at 11:01

the pata controller might be the problem, to test the reads, try running

sudo hdparm -tT /dev/sda

a few times and averaging it out, replace sda with the device you want to test

to test the writes use this command and replace your username

dd count=1k bs=1M if=/dev/zero of=/home/melvis/hdwritetest.img

outputs should be something like

/dev/sda:
Timing cached reads: 21464 MB in 2.00 seconds = 10742.66 MB/sec
Timing buffered disk reads: 210 MB in 3.01 seconds = 69.78 MB/sec

1073741824 bytes (1.1 GB) copied, 8.98227 s, 120 MB/s

TheBigCheese · 17 Oct 2012 at 01:11

Thanks very much for the reply!

The cached reads are:

4155.09 MB/sec
&
3836.64 MB/sec

Buffered disk reds are 69.71 MB/sec
&
70.80 MB/sec

Not good on the writing...
1.1GB copied, 440.712s, 2.4MB/s :eek:

That can't be good!

TheBigCheese · 17 Oct 2012 at 01:43

I should note that I'm transferring 945GB at the moment from one drive to the other (I'll leave it overnight!), it's currently showing a transfer speed of 28MB/s and it's still slowly climbing.

melvis · 17 Oct 2012 at 13:55

yea thats real low o.o id try it again when your not doing a ton of disk i/o if its still giving you 30.4mb/s (28+2.4) writes then somethings really wrong

TheBigCheese · 18 Oct 2012 at 11:38

Cheers.

After many hours copying I've got everything I needed backed up but I'm sure I'll investigiate it more over time.

I'll have to do some more investigations.

I've always used Ubuntu just from a pen drive before now but I've now got it dual booting so I'm keen to learn more about it, I really like the way some of the features are laid out - smart info so easily available on the HDDs for example.

I'll be a more frequent visitor to this sub-forum from now on!

melvis · 18 Oct 2012 at 14:38

fair enough, welcome to the penguin enclosure

Hairybudda · 18 Oct 2012 at 14:55

Does the computer slow up completely when you drop down to super slow speeds? If so you could be dropping into PIO mode for some reason (every time it's happened to me it's been a bad cable)

TheBigCheese · 19 Oct 2012 at 14:23

melvis said:
fair enough, welcome to the penguin enclosure

Thanks, I'm liking it already!

Hairybudda said:
Does the computer slow up completely when you drop down to super slow speeds? If so you could be dropping into PIO mode for some reason (every time it's happened to me it's been a bad cable)

That's a blooming good question! I haven't really noticed that but I leave it to it while it's copying that much, but...I have noticed it seeming to freeze for a few seconds before it'll give me the properties of a drive or after I try and select everything to copy.

On both those counts it seems to grind to a halt for a few seconds before coming back.

AbsenceJam · 19 Oct 2012 at 18:29

So is this same transfer actually faster under Windows or does this "usually" refer to something else? If one is heavily fragmented speed could be much slower as a consequence.

FirebarUK · 19 Oct 2012 at 18:30

Are you writing to NTFS or a CIFS share ?

melvis · 20 Oct 2012 at 08:00

yea thats a good point firebar makes, the fuse ntfs drivers rarely give me faster than 35-40 mbps for ntfs on linux, since ntfs uses a reverse engineered driver

TheBigCheese · 20 Oct 2012 at 08:51

AbsenceJam said:
So is this same transfer actually faster under Windows or does this "usually" refer to something else? If one is heavily fragmented speed could be much slower as a consequence.

Generally much faster under Windows, I was backing up a drive I'm familiar so I know the transfer speeds are much faster for it and it was backing up onto a freshly formatted drive.

FirebarUK said:
Are you writing to NTFS or a CIFS share ?

NTFS

melvis said:
yea thats a good point firebar makes, the fuse drivers rarely give me faster than 35-40 mbps for ntfs on linux

I have no idea what drivers I was using, just the bundled Ubuntu ones...didn't know you could get any others!

melvis · 20 Oct 2012 at 09:12

the ntfs linux driver isnt fast, but theres no way around it short of forcing microsoft to release implementation details for ntfs rather than reverse engineering. but dd shouldnt care too much since its raw, so something strange is still going on here

deano · 31 Oct 2012 at 08:07

if the backup drive was empty then I would have thought dd would have been quicker. windows will always be quicker than Linux writing between NTFS drives. Try it on windows with EXT3 drives