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IDEA: TV tuner software

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superticker:
So the problem is with the programmer's implementation of ATI's MMC video recording software, not the design of Windows.  Interesting.  Maybe I need to look at getting new video recording software rather than changing my disk hardware configuration.
-superticker
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Well, you can't always know beforehand how large the file needs to be. But you can reserve some minimum size, and then make sure you write largish buffers.
-f0dder (November 20, 2006, 05:50 PM)
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Yes, but you know the recorded programs will have 30-minute quantum sizes and you can compute the required contiguous blocks from that reliably plus a little extra.  Then you can release the little extra if you don't need it.  That's how MVS (IBM main-frame OS) typically does it.

If you have a partition that's mostly used for large files, you can reduce fragmentation by increasing the cluster size. If you almost solely use it for video editing purposes, you might want to try going as high as 64KB cluster size.
-f0dder (November 20, 2006, 05:50 PM)
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I seriously thought about doing exactly that, and if I knew fragmentation would be a serious problem, I would have done that when installing ATI's MMC recording software.  But the better solution would be to find a smarter video writing application that preallocates extents properly.

Using the right cluster size is an issue.  You need to fit about 5 clusters on the disk's on-disk cache and you want to have about 5-8 files open at a time, so 5x8=40 clusters needs to fit on the disk's on-disk cache.  Unfortunately, a standard non-media-server disk has a smaller on-disk cache.  That limits your cluster size.

Many server-oriented RAID controllers lets you specify a look-ahead buffer size for your sequential-file media disk arrays.  The problem is that this setting affects every disk on that RAID system.  As a result, you have to place your media server disks on an independent RAID controller from your system device, which I don't like.

But my home entertainment system doesn't use RAID.  That's just too much.  I want to keep my home system as simple as possible.  When I replace its disk, I'm going to create a separate large-cluster-size partition as you suggested just for recorded programming.

f0dder:
It's been a while since I've seend disks with less than 8MB cache, and 16MB seems to be becoming the standard for the larger disks...

So, even with 64kb clusters, you can have 8192/(64*5) = ~26 simultaneous files open, if using your calculations. Of course having 25-26 simulatenous file streams, even with purely defragmented files, is going to be horrible performance :)

nite_monkey:
wow, I leave this thread, and then every one just takes off with some random computer subject...I should start a subject and leave more often

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