RAID Performance Tests in Ubuntu Hardy

The following are results of some quick software- and hardware-RAID tests done while setting up a new Linux workstation. The workstation was built around Intel's Q35 Express chipset:

OS was Ubuntu Hardy, installed as a text-only desktop from the (current at that time) amd64 alternate desktop CD:

   $ uname -a
   Linux hardy 2.6.24-4-generic #1 SMP Mon Jan 14 18:19:11 UTC 2008 x86_64 GNU/Linux

3ware controller was detected correctly and the following kernel module was used:

   $ modinfo 3w_9xxx
   filename:       /lib/modules/2.6.24-4-generic/kernel/drivers/scsi/3w-9xxx.ko

Tests were done with Bonnie++ installed from standard Ubuntu repositories. For test purposes OS was installed on a separate SATA drive attached directly to the SATA interface (ICH9) on the motherboard. Four 10kRPM drives were then assembled into RAID-0 or RAID-10. Software RAID was done by Linux mdadm with hard drives attached to 1) onboard SATA interface; 2) 3ware controller in "single" disk mode. Hardware RAID was configured using controller BIOS and 3dm2 software utilities. 3ware StorSave profile was set to Performance in all cases while all the remaining controller options were left at their defaults. More system info and complete test data are available as one ODF spreadsheet.

Bonnie++ was run with default options, except test directory set to the mounted RAID partition (ext3 file system). Each test was repeated three times. Averages and standard deviations of output values were calculated. Relative standard deviation was typically within a few percent. In a few cases when relative standard deviation reached 10%, test were re-run a few more times. All test results then were normalized to the relevant values from testing a single 10 kRPM drive attached directly to the integrated SATA interface (Table 1). Sequential block read/write and random seek results are compared in Fig. 1.

Table 1. Bonnie++ results for a single 10 kRPM drive attached to onboard SATA interface.
Sequential block write, K/s 75916
Sequential block read, K/s 83464
Random seeks, s-1 304

bonnie results
Figure 1. Bonnie++ test results normalized to single disk performance. Higher is better. ICH9 -- disks attached to onboard Intel ICH9 SATA interface, 3ware -- disks attached to 3ware 9650SE PCIe controller, md -- Linux software RAID, HW -- hardware RAID.

March 2008, Šarūnas Burdulis