To test the performance of the N4100PRO I installed 500GB hard disk drives into it (Western Digital Caviar Black WD5001AALS, 7200rpm, 32MB buffer, SATA II). I used Intel NASPT 1.7.0, a popular NAS testing tool.
The client was a PC with an Intel Core 2 Duo 1.8GHz processor, 4GB of system memory, a Gigabit Ethernet controller on PCIe 1x bus, and 32-bit Microsoft Windows Vista. The NAS was connected to the LAN via a Gigabit Ethernet router. Jumbo Frames technology was enabled on every device that took part in the testing. I built a RAID array and created a shared folder on it and used that folder for the tests. The stripe size was set at 64KB (the default value). The NAS’s other parameters were left at their defaults.
The first diagram shows the performance of RAID0 arrays made out of different numbers of disks. This array type is not fault-tolerant. If one disk fails, data on the whole array is lost.
The maximum speed when reading large files is about 45MBps. The write speed is lower at 35MBps. If patterns with small files are used, the data-transfer rate goes down to 10-15MBps. The results are good overall but lower than the results of our NASes tested in our labs. The N4100PRO is inferior to the Atom platform in terms of top speed but wins in other patterns.
The second group of tests shows the performance of fault-tolerant arrays. The CPU load is increased and the speeds are lower. This effect can only be eliminated by means of hardware RAID controllers which are not yet used in inexpensive NASes.
The N4100PRO behaves predictably in these tests. We can see that the RAID1 has a higher read speed than the single HDD, probably achieved by reading from two HDDs simultaneously, and a somewhat lower speed at writing. The RAID10 behaves in the same way. Its performance is higher by 30% when reading and lowers to 30MBps at writing. If you are satisfied with the usage of the HDDs’ capacity in this array type, it will make the highest-performance fault-tolerant array at writing. The RAID5 is good at reading, especially when built out of four HDDs. The 4-disk RAID5 is even limited by the platform’s performance, reaching 45MBps. Its write speed is lower at only 20MBps. The RAID6 array, which can work even when two HDDs fail, has rather low performance, too. So, the N4100PRO is the slowest of the NASes I have tested when it comes to fault-tolerant arrays. For comparison, the maximum read and write speed I achieved with other models was over 70MBps with a RAID0 array and over 70 and 50MBps, respectively, with a 4-disk RAID5. So, the N4100PRO is only half as fast as the leaders.
Its performance is high enough for home use, but companies with a large number of users and/or large amounts of data should better look at other models. Don’t forget that the real speed may be even lower due to the use of background services (media servers, file downloads, simultaneous access by several clients) irrespective of the NAS model.