2009-09-14, 03:08 PM
Has anyone used the 1TB Western Digital Caviar Green drive in an HTPC to simultaneously record 2 OTA 1080i programs while watching a third?
The reason I'm asking is that most people give it high praise for it's capacity and performance in streaming media despite it being a slow HDD. But how does it handle randomly accessing three (or more HD streams) on a fragmented file system.
I calculate that a single OTA stream requires about 3MB/s transfer speeds. The drive has a sequential transfer rate of 40 - 80 MB/s but the reviews always say this is not representative of real life performance. And frankly, I have no idea how to interpret IOmeter results. What does 60 - 70 IO operations/second mean in the real world?
2009-09-15, 08:37 AM
I just bought and installed one, but haven't really tested it out yet. I'm on the road, but suspect it'll get a workout this thursday. I can test it for you on the weekend.
I did note a significant increase in performance moving my SATA drives to AHCI mode for a large file transfer.
I'm planning on getting one of these exact drives, for the same dual-tuner HD setup, but I hadn't considered the drive might have any problems keeping up. I'm interested in knowing as well.
2009-09-15, 06:11 PM
I have 2 installed in a shuttle kpc 45. I use that computer as a network server but not HTPC. Having said that, my wife and I can access all the videos that we have on it at the same time on 2 different computers and it provides the feeds to our computers with no hiccups. Also, the green series doesn't heat up like the black drives. Huge difference between the two.
2009-09-21, 12:20 PM
I did a test last night.
Recorded 3 HD streams and watched 1, no issues.
Recorded 3 HD, 1 SD, and watched 1 SD, no issues.
Great! Thanks for posting your results, Pete.
2009-11-25, 01:10 AM
Thanks to everyone for you help. The drive is great! Just to tie up this thread, see my post here (http://www.digitalhome.ca/forum/showthread.php?p=1018321#post1018321).
2010-10-15, 02:12 AM
Recently, my HD recordings began breaking up and pixilating quite badly. Some shows were unwatchable.
Turns out, that I had almost a TB of movies, videos and recorded TV. Once I freed up 200-300 GB of space, performance of the WD Caviar Green returned to normal. I was able to record two HDTV OTA broadcasts while playing a Blu-ray movie.
2010-10-15, 01:14 PM
Two words: Disk fragmentation, AKA: the storage of files in many small parts instead of large contiguous parts. When free space on the drive gets low, disk fragmentation increases rapidly. As a result, disk performance goes down dramatically. This is caused by a sharp rise in disk seeks required to find all the parts of the file. Disk fragmentation is common to all mechanical drives, not just WD Caviar Green drives. To reduce fragmentation, keep at least 10% of the drive free at all times. Some operating systems, such as Linux, make only 90% of the drive available to ordinary users so that they don't cause disk fragmentation. SSD drives are less affected by fragmentation but they are not cost effective at this time.
Turns out, that I had almost a TB of movie
And that was a 1TB drive right? Betcha had one of those "doh!" moments. :)