ssianky Posted February 21, 2009 Report Share Posted February 21, 2009 I decided to reduce the number of disk reads/writes, so I changed some cache options.As you can see from cache statisticsthe writes are good - cache writes count is much higher than file writes cont, but the reads are somewhat weird. As you can see, it read blocks of 128 kb from file, but only ~1/4 of that is sent to peers.My disk is used exclusively for torrents, so it is formatted NTFS 64 KB cluster to maximize windows cache effect and minimize file fragmentation, but seems utorrent reads 2 clusters (128 kb), and sends only 32kb of what it reads.Is there a method to tell utorrent to read only 1 cluster insteed?---Seems read cache is totally pointless, so i disabled it. Let windows do better caching. Link to comment Share on other sites More sharing options...
Switeck Posted February 21, 2009 Report Share Posted February 21, 2009 Are you allowing lots of upload slots at once, each one possibly with its own read-ahead? Link to comment Share on other sites More sharing options...
ssianky Posted February 21, 2009 Author Report Share Posted February 21, 2009 My settings are close to what you have here for 1 mbit upload and a lot of queued seeds.The problem is that utorrent read from files much more that it intends to send to peers. Link to comment Share on other sites More sharing options...
Switeck Posted February 21, 2009 Report Share Posted February 21, 2009 Did you also try testing with windows caching disabled/enabled while uTorrent's cache is enabled? Link to comment Share on other sites More sharing options...
ssianky Posted February 22, 2009 Author Report Share Posted February 22, 2009 sure. utorrent caсhing I/O - 250-400 KB/swindows caсhing I/O - 70-90 KB/sI assume that the peer negotiates 2 blocks per downloaded piece from each connected seed. Let say, a piece is 4MB / 256 blocks (16 KB/block). In that case, if utorrent caches 128 KB, but only 2 blocks are required, it will lose 3/4 of what it cached. Сhance that someone else will need rest of the cached blocks is very low if there are many seeders. Link to comment Share on other sites More sharing options...
Switeck Posted February 24, 2009 Report Share Posted February 24, 2009 Let's say you're uploading to 10 peers/seeds at once and uTorrent caches a 128 KB block for each. A full block gets allocated for each since disk reads smaller than that are often terribly inefficient. uTorrent doesn't seem to be set up to read smaller. Link to comment Share on other sites More sharing options...
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