Squall-Leonhart Posted February 10, 2022 Report Share Posted February 10, 2022 (edited) The checked process is 2.2.1, notice the pid is the same, i just forgot to uncheck it after starting 3.5.5, and Resource Monitor is weird in that it tapers off disk access within a timed period so you can see it writing out the settings after 2.2.1 closed while i've already got 3.5.5 started and doing the test 3.5.5's process has a small write underway to C: because it updated resume.dat when the recheck started. The reason is that Utorrent is opening TWO read handles on the file at the same time during the recheck, one in the System process (standard file system handle, which just about everything uses to open files) as well as one by itself, and then proceeds to fight over access to the file. 2.2.1 3.x-current This seems like it'd be relatively easy to fix, the client is basically reading the file twice, leading to the head flicking back and forth (maybe its reading to memory, and supposed to hash in memory, but its reading to memory, hashing from disk causing it to read into memory again. IDFK, It's not normal for a process to hit the disk twice to perform an operation once. For reference, heres Total Commander verifying the files hash Edited February 10, 2022 by Squall-Leonhart Quote Link to comment Share on other sites More sharing options...
rafi Posted February 11, 2022 Report Share Posted February 11, 2022 Interesting comparison. I believe that to make sense of it, you'd need to display the NUMBER of bytes read, and not only the RATE. This way, we can be sure this was read "twice". As far as I can see, using Process-Hacker , it reports the correct size in the disk stats->hashing, but only HALF the amount being read by uTorrent process. I guess the other half is being "correlated" to he OS, so I believe you are seeing Windows caching/paging "helping" out to split the READ load... just not very efficiently as before. https://www.imagebam.com/view/ME7QPTJ?full=1 Quote Link to comment Share on other sites More sharing options...
Squall-Leonhart Posted February 11, 2022 Report Share Posted February 11, 2022 (edited) The disks response time is doubled in 3.5.5 and the Queue Length being above 1.0 indicates that it is being read from 2 unique read threads at the same time The file response time under disk activity is 2ms for System process and 10ms for utorrent process. If you're doing file system tasks, you either go all in and do it all in process, or you use the System's FS api's, uTorrent in its current form is doing both leading to reduced file system performance under these particular tasks, I whole heartedly believe whoever made the changes that resulted in this had little to no idea about what they were doing at the time, which has resulted in all those little workarounds and hacks throughout 3.x to fix the disk overloads and flawed caching since. Its also quite possible that another aspect of reading the FS was nested into recheck. Regardless, the end result is that uTorrent 3.x is unecessarily more detrimental to disk wear and tear than 2.2.1 Quote so I believe you are seeing Windows caching/paging "helping" out to split the READ load I don't think so, reading two locations of the file from two threads running parallel can only be done intentionally through Programmer intent or mistake. You either do the whole task with the System using its FS api's, or you duplicate those api's in your process and do it within your own process, never both. Windows FS caching would still be employed either way. BitTorrent classic has exactly the same bug. Edited February 11, 2022 by Squall-Leonhart Quote Link to comment Share on other sites More sharing options...
MrBlackhole Posted February 15, 2022 Author Report Share Posted February 15, 2022 On 2/11/2022 at 5:39 PM, Squall-Leonhart said: The disks response time is doubled in 3.5.5 Can you state the build number? I'm currently using 46096, if the response time has been increased in new update, I would update. Quote Link to comment Share on other sites More sharing options...
Squall-Leonhart Posted February 17, 2022 Report Share Posted February 17, 2022 On 2/15/2022 at 7:37 PM, MrBlackhole said: Can you state the build number? I'm currently using 46096, if the response time has been increased in new update, I would update. it isn't inherent to 3.5.5, i went back as 3.2 and it was affected too. You have to go back to 2.2.1 to only have the single hash thread, to install that you have to disable the ethernet connection and delete the 3.x settings.dat Quote Link to comment Share on other sites More sharing options...
rafi Posted February 17, 2022 Report Share Posted February 17, 2022 Yeah, there was a design change in 3.x I/O subsystem, that might had this side effect (slower reads). Yet, there are lots of write (downloading) related functions that might have benefitted. Quote Link to comment Share on other sites More sharing options...
Squall-Leonhart Posted February 17, 2022 Report Share Posted February 17, 2022 Nothing about writes can have benefited from this detrimental read change, they are handled in entirely separate code. Quote Link to comment Share on other sites More sharing options...
rafi Posted February 17, 2022 Report Share Posted February 17, 2022 Maybe, but how do you know? Hashing checks is being done during download too, definitely file reads are done during seeding/uploading... Quote Link to comment Share on other sites More sharing options...
Squall-Leonhart Posted February 17, 2022 Report Share Posted February 17, 2022 (edited) 44 minutes ago, rafi said: Maybe, but how do you know? Hashing checks is being done during download too, definitely file reads are done during seeding/uploading... because files currently being written are only accessed via System process for read and writes for the majority of the download task. Also piece hashing is done in memory and invalid data discarded prior to disk access. Utorrent is only fighting with System on Rechecks and Completed seeds, which means the bad behavior has only been introduced for the Reading tasks for active seeding and Rechecks Edited February 17, 2022 by Squall-Leonhart Quote Link to comment Share on other sites More sharing options...
Squall-Leonhart Posted October 8, 2022 Report Share Posted October 8, 2022 (edited) This appears to be fixed for some torrents with large chunks. Edited October 8, 2022 by Squall-Leonhart Quote Link to comment Share on other sites More sharing options...
rafi Posted October 8, 2022 Report Share Posted October 8, 2022 (edited) Fixedl/improved by how much? In what build? Edited October 8, 2022 by rafi Quote Link to comment Share on other sites More sharing options...
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