Thursday, December 10, 2015

Western Digital PM2 (power up in standby) was not useful

I have a 1TB WD1002FAEX Western Digital Black which used to by my main drive but is now just a data drive. Operating systems and commonly used data can all fit on the PNY CS1211 240GB SSD. As a result, the 1TB drive doesn't really need to spin up every time the computer turns on. Enabling power up in standby seems like a good idea.

Western Digital drives support power up in standby via a jumper, which they document in a PDF. The drive did not support setting of the feature using software via hdparm -s. This is probably wise. If power up in standby is enabled via software, you could end up in a situation where your operating system doesn't recognize the drive and you can't disable the feature. Such a drive isn't bricked, but you may need to connect it to a different computer running a different operating system in order to rescue it. A jumper is very easy to remove.

After placing the jumper, the drive didn't spin up when I turned on my computer, as expected. The Gigabyte GA-P35-DS3R F13 BIOS identified a hard drive there, but didn't identify what kind and didn't spin up the drive. There was a long delay before booting, but Linux successfully booted from the SSD. Linux spun up the drive and mounted the partitions on there. It complained about failing to spin up the drive, but I didn't notice any actual problems. So far, that is all okay. Then I put the computer to sleep and woke it up, hoping the drive wasn't going to spin up. Unfortunately, Linux spun it up. So, the drive remains usable with Linux, but this feature is pointless because Linux spins up the drive anyways.

Next, I tested Windows 7. It acted as if the drive was totally non-existent. Since it wasn't detected, other software couldn't be used to spin up the drive. This means power up in standby is totally incompatible with Windows 7. It could only work if the BIOS or a 3rd party driver spun up the drive during boot and after waking from sleep.

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