Testing - Vista File Copy
Figure 1 shows a Process Monitor trace of an XP SP2 drag-and-drop filecopy read of a test folder containing a single non-compressed ripped DVD. The 4.35 GB (4,680,843,264 bytes) folder contains 38 files of various sizes ranging from 1 GB to 10 KB.
Figure 1: XP SP2 file copy read Process Monitor trace
Figure 1 shows the end of one file read and the start of another. You can see that the length of most transfers is 61,440 Bytes (60 KB) instead of 64 KB, which Russinovich's post explains is due to an SMB1.0 protocol limit on individual read sizes.
Figure 2 shows a read transfer of the same folder, but using Vista SP1. Big difference, eh? Instead of wimpy little 60 KB reads, Vista SP1 has bulked up to reading 1 MB blocks—a 17X increase!
Figure 2: Vista SP1 file copy read Process Monitor trace
So now let's see if the larger block sizes make any difference in file copy speed. Figure 3 shows a Vista Performance Monitor plot of Disk Bytes/sec of the RAID 0 array on the NAS Testbed machine while running a write drag-and-drop filecopy to the Test NAS. The average speed reported is 105,125,011 Bytes/sec or 100.2 MB/s
Figure 3: Test NAS Write Vista Performance Monitor plot - Test Bed 2 drive RAID 0
Figure 4 shows the read results for the same test conditions, which measured 112,754,606 Bytes/sec or 107.5 MB/s.
Figure 4: Test NAS Read Vista Performance Monitor plot - Test Bed 2 drive RAID 0
I also ran the tests with a single non-RAID drive and a three-drive RAID 0 array on the NAS Test Bed machine, to see if I really needed to run a RAID array and whether three drives would provide higher test capability than two drives. The results are summarized in Table 3, which contains links to bring up the related Performance Monitor plots.
|Test Bed Volume||Average Write (MB/s)||Average Read (MB/s)|
|Single Drive||103.8 [plot]||92.2 [plot]|
|RAID 0 - 2 drive||100.2 [plot]||107.5 [plot]|
|RAID 0 - 3 drive||101.2 [plot]||105.2 [plot]|
Table 3: Vista SP1 File Copy performance summary
I apologize for the different plot scales and separate plots, which make it hard to compare the plots. This was my first attempt at using the Vista Performance Monitor and I hadn't quite gotten the hang of it.
I also was confused by some Googling that I did when I couldn't figure out how to create a Data Collector Set of the captured data so that I could create a composite plot of the test runs with Excel. The references said that you had to have Vista Business or Ultimate in order to create a Data Collector set and I had only Home Premium. But while writing this article, I found that I can create data collector sets in Vista Home Premium, which is what I'll do next time.
Anyway, my take-away from the testing is that it didn't look like RAID 0 helped for the write test, but it did for the read. But there is no significant difference between two-drive and three-drive RAID 0 arrays, so I have settled on a two-drive RAID 0 array for the NAS Test Bed.