Parallelize file checking

[SiriusB]

Hi,

Can you make utorrent create a file checking thread for each queued torrent that are in different hard disks? I understand that slower machines may not be able to support more than one hash checking at a time, but you can always limit to one thread by default and let others increase this count via the advanced options page.

[DreadWingKnight]

Hash checking is typically (read: almost always) CPU-bound, not hard drive bound.

Parallel hash checking different torrents from different drives won't actually speed it up because it's not the hard drives causing the slowdown in the first place.

[SiriusB]

^You sure? Coz my conroe peaks at 4% cpu usage when checking a file while my hdd churns.

[dAbReAkA]

my P4 2,89ghz peaks at around 70%, it's CPU intensive, but yeah.. the hdd churns way too much..

[silverfire]

I wouldn't be too sure about that... My CPU usage is about 5% while hashing files whether its torrent hashing, CRC32 hashes, or MD5 hashes. I AM seeing 60MB/s read speed, though, so I'm pretty sure on higher end systems, it becomes a problem of delivering data quickly enough to the CPU for hashing.

[Lord Alderaan]

Whenever I looked at it I've noticed hash-checking to be CPU intensive but tbh I haven't checked recently. I've been assuming it still was in the last two years...

Just did a test. It indeed seems to be HD intensive here now... I was using 15% CPU and when I stopped all other torrents (also reading from and writing to the same drive) it increased to 25%. Reading between 40MB/s and 70MB/s (which isn't really near my maximum though).

As tested on Intel Core2 Duo E6600 and a SATA drive. My old 2,8Ghz PIV was always using more CPU then HD speed.

So parallel checking would indeed benefit multi-HD systems with enough CPU power. Although I don't really care much cos I hardly ever have to re-check. (Only had to just now because I was copying some files from one finished torrent to another larger unfinished torrent containing the same files)

[silverfire]

Unless you have your drives in a RAID, a sustained transfer rate of 40-70MB/s is pretty reasonable under real world conditions where other applications occasionally request data from that drive as well. While it is true that your drives can probably burst transfer at rates over that, you really shouldn't concern yourself too much with that.

[Firon]

DreadWingKnight: even on my POS athlon XP, it's HDD bound.

Anyway, because of the way µTorrent works right now, I don't believe this request is possible.