Trying out Vista
If you have been following the discussions in the Forums, you know that multiple people have reported significantly improved file copy performance when using Vista, especially SP1. The Inside Vista SP1 File Copy Improvements blog post by Mark Russinovich explains the background of the improvements. The post also reveals that, contrary to other reports, the improvements are not primarily due to Vista's use of SMB2, although SMB2 is in the mix.
So I hitched up my pants, Ghosted the iozone machine and installed Vista Home Premium. Of course, Vista didn't include drivers for the Intel 82566DM gigabit LAN interface, so I had to track down the all-OS install version of the Intel PRO LAN drivers (LAN_ALLOS_11.2_PV_TL3_132319_FULL.EXE), copy them to a flash drive and transfer them to the iozone machine. I also let Vista do its Windows Update thing, which took another hour or so.
I was in a hurry to get started, however, and didn't notice that the updates didn't include SP1, with its reported file copy improvements. So I inadvertently got a look at performance both without and with the improvements—and it's fortunate that I did!
Figure 7 includes the Vista results, which include a few other variations. I dropped the 2GB and TS-509 Pro results, to keep chart clutter down. I also narrowed the Y axis, to better see the plot differences.
- 1 GB - NAS memory @ 1 GB, iozone memory @ 1 GB
- 1GB, VRaptor - NAS memory @ 1 GB, iozone memory @ 512 MB
- 1GB, VRaptor, No dup - same as #2, but with WHS file duplication disabled
- 1GB, VRaptor, No dup, iozone Vista - same as #3, but with Vista on iozone machine (still @ 512 MB)
- 1GB, VRaptor, No dup, iozone Vista, ct - same as #4, but using Intel PRO/1000 CT PCIe adapters on iozone and BigNAS machines.
- 1GB, VRaptor, No dup, iozone Vista SP1 - same as #4, but Vista SP1 on iozone machine.
Figure 7 shows the write runs plotted. Best performance is with the internal gigabit adapters on both the iozone and "BigNAS" WHS machine, file duplication disabled and Vista on the iozone machine.
The reason that I tried the add-in PCIe adapters was to see if the internal adapters were somehow limiting performance. Instead, I found that the on-board adapters produced better throughput! But both Vista runs produced significantly better write throughput—~100 MB/s, even after OS caches were exhausted!
Figure 7: Write Performance Comparison w/ VelociRaptor and Vista
But the real surprise was worse performance using Vista SP1! Cached throughput is better than with XP running on the iozone machine. But as soon as iozone machine cache is exceeded, performance falls below that of XP!
Figure 8 holds some good news, however. It appears that Vista running on the iozone machine breaks us through the "Wall" to a new 77 MB/s high. That configuration even manages to stay up near 60 MB/s for the 1 and 2 GB file sizes!
Figure 8: Read Performance Comparison w/ VelociRaptor and Vista
Everything else however, except for the "1 GB" using the Seagate drive, clusters together at the "Wall". The differences you see are not significant and probably within the accuracy of the test method.