I am interested in what kind of performance people are getting out of their hard drives in Linux. I would like a quick, and admittedly not extremely scientific, comparison. I would appreciate it if you could do the following. First at a root prompt type where harddrive is probably either hda (IDE) or sda (SCSI.) Then post you results here along with your drive specs and SCSI controller if applicable. Thanks.

Seagate Cheetah 18XL 10K RPM
Adaptec AIC-7880 SCSI
Timing buffered disk reads: 64 MB in 3.96 seconds = 17.16 MB/sec

bastardized scsi drivers
 

Well, I WOULD post my hdparm results if it weren't for this little thing that's bugging me:

(scsi0:0:1:0) Synchronous at 40.0 Mbyte/sec, offset 15.

My hard drive isn't being used to it's full capacity apparently, seeing as how I have an Adaptec Ultra2 SCSI host adapter with a Seagate Ultra 2 hard drive. Shouldn't that read 80.0 Mbyte/sec or is that just me?

My four drives reads as follows:


/dev/hda:
Timing buffered disk reads: 64 MB in 7.43 seconds = 8.61 MB/sec
Checking hdb...

/dev/hdb:
Timing buffered disk reads: 64 MB in 16.25 seconds = 3.94 MB/sec
Checking hdc...

/dev/hdc:
Timing buffered disk reads: 64 MB in 6.64 seconds = 9.64 MB/sec
Checking hdd...

/dev/hdd:
Timing buffered disk reads: 64 MB in 4.00 seconds =16.00 MB/sec

The last one is an IBM 20G Deskstar.

-- L. James

Larry,
Do you have a little more info about the IBM drive (Model #, RPM, ATA-33 or ATA-66)? I thought the Cheetah should be faster, that is one of the reasons I started this thread. It seems to me that there should be more than a 1MB/sec disparity between an IDE drive (although the IBM Deskstar is definitely one of the best) and a 10K UWSCSI drive.

The IBM is housed outside the machine. The others are inside the case. I'll how to get the model numbers, etc... on the next power down...

Other Info on the IBM is:

Model DPTA-372050
RPM 7200
LBA: 40,088,160 sectors
CHS: 16383/16/63
Capacity: 20.5GB

Most of the other Drives are very old and will soon be replaced.

-- L. James

bickford,
I was actually having the same problem. I have an UW controller and it was reporting a 20MB/sec maximum speed. After a little poking around I just solved the problem. The adaptec board I have did NOT default to Ultra. If you go into your SCSI BIOS you should have an Advanced section. Make sure "Ultra Speed" is set to enable. Also make sure that enable disconnect is disabled for your hard drive. Here is the new benchmark:

Timing buffered disk reads: 64 MB in 3.96 seconds = 27.90 MB/sec

This seems much more reasonable to me. BTW Larry, I have that exact drive in one of my machines - it is an excellent drive. Probably the fastest IDE drive I have seen yet.

Well, since I'm at work right now I can't get into my BIOS to make those modifications I'll post the pre BIOS changes specs, and then post my new results after I check that stuff out.

Timing buffered disk reads: 64 MB in 4.45 seconds = 14.38 MB/sec

I'll let ya know how it goes when I get home to make those modifications.

Laptop, Redhat 6.2, Toshiba MK1214GAP 12GB drive

64 MB is 15.46 seconds = 4.14 MB/sec !

Although toshiba say's it has a 66.7MB's UDMA transfer rate


12 Gigabytes
9.5mm High
13ms Average Seek Time
ATA-4 Interface
66.7MB/s Ultra DMA Transfer Rate
1,024KB Buffer
300,000 MTTF Hours
3-year Warranty

66.7 MB/sec is just what the Ultra-ATA interface is capable of. You should have a sustained transfer rate, which is what the drive really performs at.

64 MB in 5.80 seconds = 11.03 MB/sec


Is that good?

Well, "good" is a relative term. So far the low was 3.94 MB/sec and was an old IDE hard drive that was about to be replaced. The high was my 10K RPM UWSCSI drive at 27.90 MB/sec and that took some tweaking. If you have an IDE drive 11MB/sec seems pretty good compared to some of the other numbers here. The one that surprises me is keef_keef's 4.14MB/sec - that seems low for a Ultra-ATA drive to me, although laptop drives do tend to be slower.

Quantum Atlas III 9100
(7,200 RPM)
Adaptec AIC 7890 Ultra2 SCSI
Timing buffered disk reads: 32 MB in 2.22 seconds =14.41 MB/sec

note: thats 'my' server at work... (PC at home is still missing BIOS chip, but they said it's in the mail and would reach me by tomorrow :-)

Is that an Ultra2 SCSI hard drive as well? I have that exact same controller and I basically got the exact same results with a 10,000rpm hard drive, which kinda sorta makes me think that controller is a little wacky under Linux. I contacted Seagate (who's hard drive I own) and they basically dished me off to Adaptec. I have yet to contact Adaptec yet.

Looking at the specs of the drive at the Quantum webside it seems to me like its an Ultra2 drive also. http://www.quantum.com/products/arch..._iii_specs.htm

I must say looking at the numbers I was astound to see others getting so much more out of there drives.

I am also surprised at some of the results. It seems that Linux SCSI drivers are still a work in progress.

Bickford - Do you have any non-LVD devices on your SCSI chain? I believe that if you do the whole chain will go down to 40MB/sec. Even at 40MB/sec it seems you should get more than the 14MB/sec you are getting. I am very interested to see what adaptec has to say.