There isn’t too much competition in the high capacity, quiet hard drive space. Right now (September/October 2005) the only drive that is pretty much universally recommended as a good quiet drive is the Samsung Spinpoint.
I had read some good things about a few other manufacturers (notably Hitachi and Seagate) but it seems that quiet drives come and go. A company will make some quiet hard drives, and then their next batch will be much noisier and not really usable in a DVR/HTPC box.
I wound up going with a 250 GB Seagate Spinpoint SATA drive. SATA was an easy choice. Faster than IDE (although probably not noticeable for what I’m using it for). New large hard drives are starting to only be around in SATA. And the fact that the connecting cable is so much smaller than a PATA IDE cable means that it’s easier to get good air flow in the case, and keep everything running cool.
Notebook Hard Drives
One other possibility that’s worth serious consideration for a set-top box is a laptop 2.5″ hard drive. These are more expensive than full-size hard drives, and you can’t get any that hold a whole lot, but they’re incredibly quiet. If you set your MythTV or whatever PVR box up to store all the video files on a server on the network, then you don’t need a lot of space in the set-top box. Grab a small 2.5″ hard drive and use that for the operating system and applications, have all the video files on the network, and you have a really quiet hard drive.
They also run very cool, and draw far less power than a full-size drive. It’s good times all around. Well, except for price. And capacity. It’s 80% good times, 20% not-so-hot times.
For me, since my PVR box will be connected wirelessly, I didn’t want to try to rely on storing everything on the network. For the most demanding tasks, like recording two things off of the air at once while playing a third program back, you’re talking about roughly 20 mbit/sec of data (varying greatly depending on the chosen recording quality). Standard 802.11g wireless claims to give you something like 54mbps (56? I forget). That falls off very quickly as your reception goes down (and I don’t even know if you can ever really get that high). So relying on my wireless to handle that bandwidth didn’t really seem like it would work.
But if you can set up a wired 100mbit network for your PVR, definitely think about a laptop hard drive.