Performance

Tests were run with 1.30 firmware using our standard test process using Gigabit and 4k jumbo frame Gigabit LAN connections with all four drives configured in single RAID 0, 5 and 10 volumes.

Figure 3 summarizes all the results with non jumbo frame test results plotted. Write cache effects start to drop out at different file sizes for each volume type. But by 512 MB file size, true hardware performance dominates.

For writes, RAID 0 and 10 performance is about equal in the mid- 20 MB/s range, with RAID 5 the slowest at around 20 MB/s. Read performance is about the same for all three volume types and trends higher in the mid-to-high 30 MB/s range.

Figure 3: Performance Benchmark summary

RAID 5 Write performance with a 1000 Mbps LAN connection averaged over the 32 MB to 4 GB file sizes and with cached results above 125 MB/s removed from the average measured 44.2 MB/s with read speed significantly higher at 46.9 MB/s.

RAID 5 file copy write performance of 23.8 MB/s using our Vista SP1-based test ranked the ES ahead of other four-drive Kirkwood NASes like the Seagate BlackArmor NAS 440 and Iomega ix4-200d, both of which also run at 1.2 GHz clock rates. You can see in Figure 4 that the ES is essentially the same as the TeraStation III at 24 MB/s.

Figure 4: RAID 5 Filecopy write ranking

A check of Figure 5, which shows the RAID 5 filecopy read rankings for four-drive NASes, reveals quite a different story, however. The ES drops to the bottom of the 1.2 GHz Kirkwood pack at 39.9 MB/s and the TeraStation III leaves the ES in the dust at 55.1 MB/s.

Figure 5: RAID 5 Filecopy read ranking

I also checked backup performance to an Iomega UltraMax Pro Desktop Hard Drive configured in RAID 0 attached to the ES's USB 2.0 port. The test copies the 4.35 GB ripped DVD test folder that I use in the NAS Chart Vista SP1 file copy tests from the NAS to the attached drive. The results are summarized in Table 1.

Table 1: Backup throughput test summary

These results are close enough to the TeraStation III that I wouldn't make backup performance the tipping point in a buy decision. Both products pale in comparison to the speeds I see in competitive NASes, particularly QNAP and Synology.

I also had the LinkStation Duo around from its review, so ran a network backup test from the ES to it. At 9.96 MB/s for an unencrypted, i.e. not over an SSL connection, I'm again not impressed. Buffalo needs to pay more attention in this area given the strides that their competitors are making.

Closing Thoughts

Updated 4/29/2010

If you're a Buffalo NAS fan looking for a four-bay NAS with RAID 5 and 10 support and on a tight budget, then the ES is probably what you're looking for. If you're willing to give up a bit of performance and shop carefully, you can keep about $100 in your pocket (current difference between 2 TB ES and III) or more vs. buying a TeraStation III and get all the same features.