8. NAS Performance

As I have with other NAS products, I used IOzone to check out the WL-HDD's file system performance. (The full testing setup and methodology are described on this page.) All checkout was done using the Hitachi HTS548080M9AT00 Travelstar 80G 5400RPM drive that ASUS supplied for the review. This 5400RPM drive has an ATA-6 interface and 8 MB cache and you can hit the Hitachi product page for other drive specs.

NOTES:
• All testing was done using the WL-HDD Ethernet interface.
• The flat zero value spots at the left front and right rear of the plots are zero value areas due to the IOzone test parameters that I set and not due to performance problems
• Keep in mind that the maximum raw data rate for 100Mbps Ethernet is 12500 kBytes/sec
• If you want a closer look at the test data or generate your own plots, download the Excel test result file here.

Figure 17 shows a 3D surface plot of the WL-HDD's write performance using file sizes from 64 kBytes to 1 GBytes and record sizes from 4 kBytes to 16 MBytes. Note that the plot is oriented so that larger file sizes are closer to the front.

Figure 17: WL-HDD NAS Write performance
(click on the image for a larger view)

I ran the test with file sizes up to 1 GByte in order to ensure that the test covered areas where there were no caching effects from my test computer's 512 MB of memory. (Caching is what causes the "mountain" rising out of the plot's plateau.) You can see in Figure 17 that non-cached write performance kicked in above a 32 MByte file size and at 512 kByte record sizes for all file sizes. Peak performance (aided by caching) of around 50 MBytes/sec occurred with file sizes between 0.5 and 4 MBytes and record sizes 256 kBytes and under.

Read performance (Figure 18) was significantly slower - typically around 2 MBytes/sec - causing me to adjust the vertical plot scale to one-fifth that of Figure 17.

Figure 18: WL-HDD NAS Read performance
(click on the image for a larger view)