Drive performance sucks, is it a kernel/driver issue or just inferior hardware?

santana · 07-24-2008, 09:28 AM

Hi,

recently I bought a workstation from dell (not my choice company policy), and I have been totally dissatisfied with the hard drive performance. I see about 60-80 MB/s while on my older workstation which I built myself for 1/2 the cost I was seeing about 150 MB/s.

I need some help to track down weather this is a linux driver issue or just if I just have inferior hardware.

How can I figure out if this is a driver issue? Here is some information which I have scraped from the system:

hdparm says

Code:

tycho:~$sudo hdparm -t --direct --verbose /dev/sda

/dev/sda:
 Timing O_DIRECT disk reads:  228 MB in  3.02 seconds =  75.37 MB/sec
Trying legacy HDIO_DRIVE_CMD
tycho:~$sudo hdparm -t --verbose /dev/sda

/dev/sda:
 Timing buffered disk reads:  172 MB in  3.02 seconds =  57.00 MB/sec
Trying legacy HDIO_DRIVE_CMD

lshw says

Code:

*-storage
             description: SATA controller
             product: 631xESB/632xESB SATA AHCI Controller
             vendor: Intel Corporation
             physical id: 1f.2
             bus info: pci@0000:00:1f.2
             logical name: scsi0
             logical name: scsi2
             version: 09
             width: 32 bits
             clock: 66MHz
             capabilities: storage pm ahci_1.0 bus_master cap_list emulated
             configuration: driver=ahci latency=0 module=ahci
           *-disk
                description: ATA Disk
                product: WDC WD5000AAKS-7
                vendor: Western Digital
                physical id: 0
                bus info: scsi@0:0.0.0
                logical name: /dev/sda
                version: 12.0
                serial: WD-WCAS86047034
                size: 465GiB (500GB)
                capabilities: partitioned partitioned:dos
                configuration: ansiversion=5 signature=41ab2316
              *-volume:0
                   description: EXT3 volume
                   vendor: Linux
                   physical id: 1
                   bus info: scsi@0:0.0.0,1
                   logical name: /dev/sda1
                   logical name: /
                   logical name: /dev/.static/dev
                   version: 1.0
                   serial: f6195377-258a-4ff5-b61e-0be84cd965bb
                   size: 457GiB
                   capacity: 457GiB
                   capabilities: primary bootable journaled extended_attributes large_files huge_files recover ext3 ext2 initialized
                   configuration: created=2008-04-02 11:23:00 filesystem=ext3 modified=2008-07-21 09:12:49 mount.fstype=ext3 mount.options=rw,relatime,errors=remount-ro,data=ordered mounted=2008-07-21 09:12:49 state=mounted
              *-volume:1
                   description: Extended partition
                   physical id: 2
                   bus info: scsi@0:0.0.0,2
                   logical name: /dev/sda2
                   size: 8887MiB
                   capacity: 8887MiB
                   capabilities: primary extended partitioned partitioned:extended
                 *-logicalvolume
                      description: Linux swap / Solaris partition
                      physical id: 5
                      logical name: /dev/sda5
                      capacity: 8887MiB
                      capabilities: nofs

kilgoretrout · 07-24-2008, 09:55 AM

That range is pretty normal for a sata drive. I've never seen anything near 100MB/sec from hdparm on any system I've had. I'm curious what type of setup you have in your old system that gets those numbers.

santana · 07-24-2008, 12:01 PM

Hi,

it was a dual proc, dual core opteron system,

http://www.asus.com/products.aspx?l1...30&modelmenu=1

, and I took a couple of drives out of the cabinet of spare parts for our cluster. These drives are likely to be high end drives...

On most of the workstations I have used recently, I have seen well over 100 MB/s typical.

This dell box is supposed to be a mid end workstation.

kilgoretrout · 07-24-2008, 01:05 PM

Wow!! That's hardly consumer grade hardware. I can assure you the rest of us mere mortals are only getting 60-80MB/sec with our sata drives. I've never gotten a 100MB/sec hdparm with any non-raid system I've used. But then again, I don't have access to the high end stuff that you have.

You can check the hard drive and make sure that it is not jumper limited to sata 1; Seagate sata 3 drives were shipped that way by default the last time I got one. However, I don't think you would see a dramatic improvement even if you corrected that erroneous jumpering.

santana · 07-24-2008, 01:20 PM

hmmmm, I may have been mistaken on those numbers.... Thanks for the feedback.

arizonagroovejet · 07-24-2008, 02:00 PM

60-80MB/sec is perfectly respectable.

mike@continuity:~$ sudo hdparm -t --direct --verbose /dev/sda

/dev/sda:
Timing O_DIRECT disk reads: 236 MB in 3.02 seconds = 78.10 MB/sec
Trying legacy HDIO_DRIVE_CMD

If you want to see really sucky performance try running without DMA enabled

lazlow · 07-24-2008, 02:17 PM

Some of the new Seagate drives are seeing 100MB/sec but most are still in the 60-80 range.

Electro · 07-24-2008, 04:50 PM

Go in the BIOS to set the controller to something else besides AHCI.

I would not call that drive a workstation drive. Several Western Digital Raptor drives setup in a RAID level 50 on a 3ware controller is more like a workstation setup. For a single drive workstation, an Hitachi Deskstar 7K1000 is a good choice. Use XFS as the file system for high throughput.

You will not get the throughput that hdparm or sdparm are showing because of the over head of file system, controller, and bus. The utilities hdparm and sdparm provides raw performance, but not true performance.

Throughput does not mean anything if the hard drive has poor accessing times. Both throughput and accessing times goes well together. Though throughput can always be increase using striped levels of RAID, but accessing times can not.