Figure 20 shows a composite of FreeNAS and Ubuntu Server write test results. All testing was done with the iozone testbed system used in this series running Vista SP1 and with 512 MB of memory. A gigabit LAN connection was used with no jumbo frames. The tests shown are:
- RAID 0 Chunk 64 kB - Ubuntu RAID 0 with chunk size set to 64 kB
- RAID 0 Chunk 32 kB - Same as #1, but chunk size set to 32 kB
- RAID 0 Chunk 64 kB - Ubuntu RAID 1 with chunk size set to 64 kB
- Single drive - Ubuntu w/ single ext3 formatted drive
- FreeNAS RAID 0 - FreeNAS RAID 0
- FreeNAS RAID 1 - Lg file + tune - FreeNAS RAID 1 w/ Large read/write and Tuning options enabled
Figure 19: Atom Write performance - Ubuntu Server and FreeNAS
The Y axis has been expanded to show the 66.9 Mbps measured PCI gigabit transfer rate reference line. Basically, Ubuntu Server blows the doors off of FreeNAS, with at least 2X write performance in all modes.
Note that using the suggested 32 kB chunk size actually reduced performance somewhat over using 64 kb chunks. I didn't try any other chunk sizes, but it looks like something that might be worth playing with.
The read results in Figure 20 also show Ubutnu server beating out FreeNAS, but by not as wide a margin. It also appears that RAID 0 is providing no speed advantage over single drive or RAID 1, contrary to the results presented here. Since the speeds are beginning to bump up against the PCI gigabit limit, that could be the problem.
Figure 20: Atom Read performance - Ubuntu Server and FreeNAS
I didn't bother adding the D-Link DNS-321 plot line to either of the plots, since its low teens speed is no comparison with the Ubuntu results. Instead I plotted the RAID 1 results that I took for the Intel SS4200-E, which currently tops the RAID 1 NAS Charts.
Figure 21: Atom Write performance - Ubuntu Server, FreeNAS, Intel SS4200E
You can see in Figure 21 that the SS4200E's write performance is more like Ubuntu Server's than FreeNAS', even without the benefit of being tested on Vista SP1. But Figure 22 shows that its read performance is more like FreeNAS', but keep in mind this is with iozone running on an XP client.