Plextor claims that the PX-EH25 can support speeds up to 94.5 Mbps, which looks quite fast upon first glimpse for a storage device. Keep in mind though, Plextor is using Mbps, not MBps, which is commonly used to gauge speed of hard drives. 94.5 Mbps translates to 11.8 MB/s, which isn't quite as impressive. In contrast, most modern 7,200 RPM Serial ATA hard drives can push 30-40 MB/s, so the network interface does act as a bottleneck. One can only wonder if Plextor used Gigabit connectivity in this system, if this could have equated to better overall transfer rates.
We tested the drive out by comparing it to a standard USB 2.0 enabled 7,200 RPM backup disk, along with our own file server, which connects via Gigabit Ethernet, which itself also uses 7,200 RPM storage. We copied the same exact 1 GB file over to the three devices from a central PC, and here are the speeds which we achieved.
Disk Bench File Copy Tests
Copying the 1 GB file over to a USB 2.0 based backup storage was the quickest at about 28 MB/s, whereas copying that same 1 GB file to a Gigabit connected network device rated slightly slower at about 27 MB/s. The Plextor PX-EH25 device, however, scored rather poorly at 7.3 MB/s, or roughly 58 MBps. This was a direct connect via CAT-5, so no other network traffic was involved with this test. Those scores aren't particularly great, and we're left wondering if a faster network interface could have helped transfer rates. There are many other NAS devices using Gigabit connectivity nowadays, and given how inexpensive Gigabit components are in today's market, it's somewhat puzzling why this device is still 10/100 based.
Benchmarks aside, the drive should still be plenty fast for any kind of basic home storage and for home theater usage. The drive is still quick enough so that we did not notice any lag time when coping dozens of RAW digital camera photos to and from the drive, and we were able to stream HD content from the drive without any slowdowns. We were even able to stream HD content from the drive to multiple sources as well, which is nice for home theater setups. Say, for instance, if two people want to stream movies or music from a single source - the unit is still plenty speedy for this. For basic office documents, the PX-EH should work great.