> I guess YMMV depending upon exact OS and software used to access the device, but most media playback software will run a big enough local cache that it is requesting chunks of data long before it absolutely requires them for playback to work without a hitch, giving the drive more than enough time to wake up if it has parked itself.
On a Windows 7 machine with lots of RAM and a 3TB WD Green secondary drive, Foobar 2000 music playback and VLC video playback both exhibit the problem behavior. I don't think whatever read-ahead caching those programs do is designed to accommodate the latency involved in getting the drive going again.
Also, consider how a random playlist of thousands of songs works - reading all the songs into RAM isn't really an option. Foobar 2000 definitely does some read-ahead caching, I've noticed that a few seconds of music will sometimes play at the beginning of a song and then pause, as the software blocks waiting for the disk to get going.
I believe you, I just haven't run into this myself and I guess it is correct that YMMV depending upon setup then.
All of my WD Green drives are sitting in a Linux server and exposed as samba shares to various computers (including some running Windows 7) and HTPC devices. My guess would be that this setup results in greedier read-ahead caching by the local OS because of the relative slowness and unreliability of accessing blocks via a network-share file versus what the OS considers to be a local file.
On a Windows 7 machine with lots of RAM and a 3TB WD Green secondary drive, Foobar 2000 music playback and VLC video playback both exhibit the problem behavior. I don't think whatever read-ahead caching those programs do is designed to accommodate the latency involved in getting the drive going again.
Also, consider how a random playlist of thousands of songs works - reading all the songs into RAM isn't really an option. Foobar 2000 definitely does some read-ahead caching, I've noticed that a few seconds of music will sometimes play at the beginning of a song and then pause, as the software blocks waiting for the disk to get going.