QNAP TS-509 Pro Turbo NAS ReviewNemo - May 5, 2009
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Testing is not just about performance results. Some of the more practical aspects include operational aspects such as power and cooling.
Cooling for the TS-509 is provided by a rear-mounted 120mm fan. The fan is temperature controlled, a feature QNAP refers to as Smart Fan. As we saw in the System Tools/Hardware Settings section earlier, you can let the system handle the speed of the cooling fan or override those settings with values of your own choosing. With Smart Fan enabled the fan rotated slowly enough to keep temperatures in check without being noticeably loud. QNAP claims noise levels of 34.2 dB in standby mode and operational noise levels 41.2dB. Cool air is provided by air vents along the lower front of the case along with slots on the front of each drive tray.
During the course of running the performance tests the outer steel case never became warm. To test how well the system cools itself, I used the NAS performance Toolkit to run a full series of tests in a RAID 5 configuration and monitored the S.M.A.R.T. drive temperature readings as well as the system temperature reported on the System Information page of the management UI. To monitor the interior case temperatures I inserted a digital temperature probe into the case with the probe positioned in the center of the case at the rear of the drives. Temperature readings were taken prior to the run with the hard drives spinning and then throughout the test.
|Ambient Room||22 C||22 C|
|CPU||35 C||38 C|
|System||43 C||45 C|
|Case Interior||32 C||33 C|
|S.M.A.R.T. Drive 1||35 C||36 C|
|S.M.A.R.T. Drive 2||33 C||35 C|
|S.M.A.R.T. Drive 3||33 C||35 C|
|S.M.A.R.T. Drive 4||32 C||34 C|
|S.M.A.R.T. Drive 5||34 C||35 C|
|Fan Speed (RPM)||860||865|
As you can see cooling performance was quite good with only modest increases in temperatures even after an extended period of high drive activity levels. The fan pretty much stayed at its lowest speed, keeping the unit very quiet.
One of the benefits of using a NAS server such as the TS-509 over a standard PC is lower power consumption. You can set the drives to go into hibernation using the management UI. It's a simple matter of picking a setting from a drop down list and is easy to set.
I tested the various power usage levels of the TS-509 at idle with the disks spinning but no activity, during a full test with read and write activity with the drives configured in RAID 5 and finally in power management mode with all drives set to power down after 5 minutes. All measurements were taken with a P3 International P4400 Kill A Watt power meter.
|Power Mgt. Mode||N/A (fail)|
|RAID 5 Test||73-85|
I was more than a bit surprised to see the the results of the power test especially when put up against the Synology DS408 comparison unit. However, given that the unit uses an Intel Celeron 1.6GHz processor, compared to the DS408 with its 800 MHz Freescale MPC8543 system-on-chip processor, plus the fact that the TS-509 has twice the memory and an additional hard drive for the TS-509, you can expect it to use more power. The hard part comes in reconciling the numbers I saw to the numbers published on QNAP's web site: 39W in sleep mode and 63W in operation with 5 x 640GB HDD installed.
In addition, I never observed the unit setting the drives to hibernate. Even after extended idle times, power consumption remained rock steady at 71W. I even disconnected the Ethernet cable to ensure there was no communication going on between the test computer and the unit with no luck. QNAP's documentation says that during the hibernate state the power LED will be blue and the status LED will be off in hard disk standby mode and I never saw an indication of this, even with the unit being left idle overnight.
While I would have liked to seen lower idle power consumption, 70-85 watts is still less than what you could expect to see from even a low-powered PC.