IOzone was used to test the FlexNet's performance (the full testing setup and methodology are described on this page). The test unit had the latest 1.4T3 firmware and was tested with a 100 Mbps LAN connection.
The FlexNet won't win any speed awards. In fact, it ranks third from the bottom in the 100 Mbps Write NAS Chart for single-drive NASes with average speed of 2.8 MB/s for filesizes 32 MB to 1 GB. It does a bit better for read, averaging 5.8 MB/s over the same file sizes, placing it in the bottom half of the rankings.
Since I could only run a single read and write benchmark, I'll skip right to the competitive comparison, choosing the LaCie Ethernet Disk mini (V2). Figure 10 shows the write comparison along with a 100 Mbps Ethernet reference line. The LaCie averages 7.6 MB/s over the "large" filesizes vs. the FlexNet's 2.8 MB/s.
Figure 10: Write performance comparision - 100 Mbps LAN
Figure 11 shows the read comparison, where the LaCie once again beats the FlexNet, averaging 8.4 MB/s. This isn't really surprising, given the mini's more powerful Marvell Orion processor and 64 MB of RAM.
Figure 11: Read performance comparision - 100 Mbps LAN
Since you're probably wondering whether the FlexNet's USB-connected performance is any better, I just happen to have some data for you.
Figure 12 shows the FlexNet's 100 Mbps LAN write curve plotted along with its USB-connected performance. I also included data for a old Maxtor One-Touch 160 GB USB drive that I had in the SmallNetBuilder closet. The Maxtor drive does better than the Buffalo, averaging 17.7 MB/s vs. the FlexNet's 15.2 MB/s across 32 MB to 1 GB file sizes.
Figure 12: Write performance comparision - USB
Figure 13 shows the read results, with the FlexNet actually doing better than the OneTouch at almost 29 MB/s vs. the Maxtor's 20 MB/s, after caching effects drop out at the 256 MB and larger file sizes.
Figure 13: Read performance comparision - USB
It's clear that Buffalo isn't trying to position the FlexNet as a full-fledged NAS. It simply doesn't have either the features or performance. It is more an alternative to the lesser-known dual-mode drive enclosures, like the discontinued CoolMax CN-570 or its CN-590 replacement.
Pricewise, the FlexNet at $123 (lowest Pricegrabber price as I write this) is between rolling your own (CoolMax CN-590 + WD5000AAKS drive = $104) and the LaCie Ethernet Disk mini v2 at $140.
But both the CoolMax and LaCie mini provide more features than the FlexNet and the LaCie definitely has better LAN performance as well as a Gigabit Ethernet LAN port, too. On the downside, I had to wrestle with the LaCie to get it working over its LAN connection, but perhaps they have fixed that with a firmware update by now.
If you're more comfortable buying from a "name" brand, want something that just plugs in and works, aren't looking for speedy transfers and would like the flexbility of being able to occasionally park an external USB drive on your LAN, then the FlexNet will suit you well.