Hard Disk Monitoring

In a previous post I discovered some excessive load/unload numbers for drives mounted in an external multi-bay dock. In trying to troubleshoot the problem, I switched connectors from eSATA to USB3 (the dock supports both). After switching to USB3, I noticed that the drives were reporting higher temperatures, most notably a 4TB drive was reporting between 41-43C (before the connector switch, the temps were in the mid 30's for that drive). I decided to temporarily switch back to eSATA and immediately the reported temps dropped about 8C (for all 4 drives in the dock). While some of this may have been due to the drives powering down for about 15 mins during the switch and reboot, HDS records show that when the dock was connected via eSATA, the drive temperatures were consistently lower than when the USB 3 connector was used. Unfortunately, using my eSATA connection caused the multiple loads/unloads problem, so I can't stay with the eSATA connector (at least for now).

BTW, I tried adjusting the APM values to see if this would significantly affect the reported temps. I thought that maybe "minimum power consumption without standby" would keep the drive at a lower temp without unnecessarily increasing the load/unload count, but it hasn't seemed to change things (USB3 temp is still high, and eSATA still causes multiple loads/unloads).

This temperature difference could mean that for some reason the USB 3 connection causes the drives to run hotter or that the reported temps are different based on the connection (though the actual temps may not have changed). I don't currently have an IR sensor to measure the real temps, so I can't definitively choose which of the above is true. Any ideas which it may be?

Also any specific recommendations on a reasonably priced IR temperature sensor (possibly available through Amazon)?

Thanks for sharing the experiences, sounds really interesting!

Generally there should be no difference in temperatures depending on the connection: the drives do not "care" if they managed directly by SATA (or eSATA) or via an USB bridge, they should report the actual, correct temperature values.

Difference can be caused by the design of the dock, for example if the USB chip is producing heat and increases temperature of the drive(s) near it when used. In theory this may happen, but in practical, it is hard to imagine that this chip increases the temperature inside the dock and increases the temperature of ALL drives (especially with 8 C degrees).

Yes, the sampling frequency may be interesting. By default Hard Disk Sentinel detects status once per every 5 minutes, so it is possible that since the last readout if you power down the dock (to swap connetions) and then power up again, the temperature may change.
Maybe to 100% sort out, you can
- adjust the Configuration -> Advanced options -> Detection frequency to detect more frequently (eg. once per every minute or even more frequently)
- power DOWN the dock for longer time (at least some hours) to allow drives to cool down
- power UP on USB connection and observe temperatures for some time, eg. 10-15 minutes to reach "normal" idle temperatures)
Then do the same with eSATA connection.
(I'd be happy if you use Report menu -> Send test report to developer option in both cases, I'd be happy to examine the reported values in both cases and compare them when generally other operating conditions are same).

From the information in your other post and this, I suspect the difference is related to the load/unload cycles and the difference about how the drives work in this area - as these may cause difference in temperature of the drives too.

May I ask the manufacturer and complete model of the external dock? I'd get such for testing and investigation - about both its design, USB chipset and operation related to the increasing load/unload count.