Serious bug with uTorrent and win8 RTM

[kilara]

I was using uTorrent 3.2 stable on my Win8 RTM with no problems until today.Suddenly i started to notice that uTorrent was using all of the write cache i set(even the max limit 1800 MB cache got filled(and utorrent stopped responding) when i added 2 10GB+ torrents with TV Show Series of 10+ files per torrent) and then show a disk overload message and my download speed plummets down.

I opened the resource monitor and i notice that uTorrent was maximizing my HDD transfer speed in what seemed to be allocating the space for the files from the torrents.When i checked the total file size of both folders i was downloading the torrents in,i noticed that it was growing over time-meaning it was allocating the space gradually which i don't know why was filling my write cache fast.

The downloaded pieces just don't get written to disk(they do,but veeeeeeeery rarely).They all go into the cache until it fills.And even then they are still not forced to be written to the disk.After a few minutes(depending on the size of the torrent/torrents added and probably the speed of your HDD all goes back to normal and the pieces start get written to the disk and the cache drops down to and keeps around 30-40 MB.Also utorrent process was not going away when i exit untill the allocation was complete.

This wasn't happening before.Removing and putting a check on the Allocate files option didn't seem to do anything.Moreover before when i started a torrent utorrent would instantly reserve the space needed while now it is killing my HDD and filling the write cache which leads to the above mentioned problems.I tried reinstalling-no help.Tired the beta(which is supposed to have win8 support)-no luck.Even tried 2.2.1 version and still no luck.When i load those torrents when i boot in Win7 the problem goes away.The weird thing is that i didn't notice such behavior in win8 until today.

Any idea what is going on?

Tell me if you need any more info.

[DreadWingKnight]

Does the problem persist with 3.2.1 or 3.3?

[kilara]

Yes.I'm currently using 3.2.1 beta and it is still the same.haven't tried 3.3 alpha tho.

Edit:It just ate like 1G of my 1800MB set cache for just one of the torrents after i restarted utorrent when it got unresponsive.This is insane.After that it started writing the torrent pieces to disk and cache dropped back to normal.

[kilara]

Ok.This is really weird.I read about sparse files and as far as i understood it,the behavior i had was exactly what it should be if i had diskio.spars_files set to true.But in my case it was set to false as it is by default and i never changed that setting since i started using uTorrent,NEVER.I tried to see if changing it to true would make a difference.And voila, everything went back to normal.I didn't see write cache skyrocket or any abnormal HDD activity in Resource Monitor.As soon as i load a torrent when diskio.spars_files is set to false i see the abnormal behavior i explained in the first post.

Did i completely misunderstood the way sparse files setting works or there is something really weird going on here?