Random speed drops

[wewt]

Hello

I have a problem with random upload speed drops (sometimes even download but not so often). Speed drops drastically from max to 0,1kb/s on all active torrents and then very fast back up again. First I suspected my isp but whenever it happened I quickly tried maxing out my connection with some transfer or a speedtest and it worked fine. Then I thought maybe my disk couldn't handle it anymore so I raised the cache and disabled anything that tries to reduce memory usage so it truly uses the cache and it didn't help either.

One more thing I noticed which is very strange, when the drop was happening I tried setting a global up limit to let's say 2300kb (I'm on 20/20mbit) it immediately rose again. And if I set it to 0 (unlimited) it starts to drop and then if I set it back it goes up and so on... in real time? I wonder what exactly does this setting do apart from capping your desired global torrent upload speed?

This has been happening through a couple of 1.8.4 and 1.8.5 builds up to the latest.

Oh and my isp isn't throttling traffic so that's not the case either.

Thanks.

[Switeck]

1st and 2nd links in my signature.

Problem could be network overload causing speed drops. Just because your internet connection can go that fast doesn't mean poorly written software firewalls or networking drivers can keep up!

[wewt]

Thanks for replying.

Yes I suspected ethernet drivers at first and updated them just in case. My mobo has 2 gbit ethernet integrated and I doubt network can't keep up. Plus I use a cat. 6 utp cable directly to the ftth modem.

Regarding firewalls I dont use it and have it disabled and no antivirus programs either. Unless there's something else going on with Vista. (Is it possible it all has something to do with Vista 64bit?)

Wasn't implying that utorrent is a poorly written software at all, its one of the best clients around, I just find it weird that something "unimportant" as setting the global upload cap can cause sudden changes like that.

I've been through all the guides and links, is there anything else I can do or any information I can give you. I would really appreciate more help.

Regards.

[Switeck]

Do you ever see any warning/error messages at bottom left corner of uTorrent's window when speeds fall really low?

Are you losing connection to seeds/peers when that happens?

Do the flags for the seeds/peers change from "D" to "d"?

[wewt]

No, I haven't seen any warning or error messages anywhere and flags stay the same when dropping begins.

Depending on how long the drop lasts, but if they're longer then yes eventually I lose connection to peers and seeds.

I guess this could seem like my "internet" simply dies for a while, which would make it my isp's fault. But I'm still not convinced on that because I tried for example a speedtest lots of times when the drop happened and it always maxed out.

If I had to describe it somehow, it looks like it just dozes off for a minute and then wakes up very fast. The speed jumps are by +30kb/s at least.

[Switeck]

A problem some people seem to have is uTorrent quits acting reliable if max connections per torrent is set too high relative to global max connections.

The absolute worst is when max connections per torrent is greater than global max connections.

[zyrobs]

I have this problem too, and I know a LOT of other people who have it too (all of them are on at least 10mbit connections) - utorrent randomly drops speeds to 0, waits for a while, then gets things going again. It looks like utorrent just can't seem to handle high bandwith connections.

As far as I could track down, the main problem is the disk caching. If I'm transferring too fast, the disk cache just hangs up, preventing utorrent from transferring anything. Neither the cache nor the actual hdd is read when this happens - even hashing a torrent via forced re-check will stop progressing!!!

Right now, I'm seeding at my max speed (25mbit, approx 3200kbyte/s). With read cache disabled, I get a straight line on my max upload speed (everything is set according to the speed guide, except the upload which was bumped to 3200). But if I enable the read cache, utorrent will start random speed drops.

Download is unaffected, mainly because I only have one very slow download going. But I've had this random speed-drops-to-zero issue with downloads as well, in the past.

It's not caused by a weak router, because I'm not even using a router.

It's not caused by weak networking hardware, because with the disk cache disabled, utorrent is constantly maxing out my bandwith.

It's not caused by my ISP not being up to it, because I'm maxing out my bandwith for a week straight by now.

It's not caused by insufficient HDD performance, because I actually get better speeds if I put more toll on the HDDs (by disabling the cache).

And It's not caused by bad settings, since everything was set up according to the setup guide, or left on default, or is a trivial option (like old style category list).

I've been trying to find the cause for this phenomenon for almost two years by now, and so far disabling the disk cache was the only thing that worked. I've tried using a very, very big cache as well (up to 1gb, both with "reduce memory usage..." on and off), but even that could not fix the issue, zero speed drops still happened. Only disabling the cache altogether is what helped me so far.

Unlike the topic opener, changing the upload/download cap had no effect either.

I'm sure the issue lies somewhere in the fact that I have roughly 1tb shared in 100 torrents, but with the disk cache disabled, utorrent can handle it perfectly fine...

edit: also, I thought I should mention, that even when my bandwith is not maxed out, utorrent still does the drop-to-zero thing with the cache enabled, if I put a lot of toll on my CPU. Such as, playing games. Heck, even running MyDefrag on a non-system drive, that has no torrents stored on it, can trigger the speed dropdown. It's crazy.

[Switeck]

zyrobs,

Re-enable both read and write caching of torrents by uTorrent, but disallow windows caching of disk reads and writes.

Uncheck Reduce memory usage, turn off read cache if upload speed is slow, and remove old blocks from cache.

If that doesn't work, I'd call that a SEVERE uTorrent bug!

What version of uTorrent are you using?

[zyrobs]

>I'd call that a SEVERE uTorrent bug!

Quite so. Here are some pictures with all my (cache) settings.

http://img257.imageshack.us/i/utorrent1.png/

Arrow indicates where I turned read caching back on.

http://img218.imageshack.us/i/utorrent2.png/

Cache status. Note that, while it is not apparent here, write cache is unaffected. While I was experimenting a few days earlier, I still had a download going, and it was completely unfazed even as all uploads nuked themselves out. (it was a relatively slow download, around 1-200kbyte)

While this drop is happening, utorrent can't even hash data via forced re-check. I have not tried creating a torrent during this period, however, so I'm not sure if that's affected as well.

http://img52.imageshack.us/i/utorrent3.png/

Read cache turned back off, upload rockets back on.

http://img257.imageshack.us/i/utorrent4.png/

My upload rate for the last 10 HOURS with read cache disabled.

http://img503.imageshack.us/i/utorrent5.png/

Read cache turned back on, period of 10 minutes total.

All pictures were made with version 2.0 RC2. But, I've been having this issue since at least one and a half years by now, with 2 different ISPs, and 2 different routers (+ with router removed), and seen it happen on completely unrelated computers used by other people, the only constant was utorrent being used as the client. I've been always using the official latest version, until the last month or two, when I switched over to 2.0 beta, and then RC1/2 (after the 2.0 was finally enabled on a few bigger trackers). I'm not quite sure what versions will this timeframe put me at, but it covers all of 1.8 at the very least.

One thing I should mention, is that 1.8.x did this for the DOWNLOAD as well, not only upload. But, with the 2.0 versions released at least beyond September, downloads are not affected.

(a friend of mine was having problems with utorrent, same exact problem, but with downloads too. Since I didn't knew it was the cache at the time, I proposed switching to the 2.0 beta - and he got straight 10 mbyte downloads with the 2.0 beta for as long as I was testing it, across multiple torrents, with all the default utorrent settings. This happened sometimes after September, don't know exactly, but it was late august/early september when they bumped up our speed to 80mbit, so it was around that time).

I still have a copy of 1.6.1 somewhere, I'll test it with that, but it'll take a while since it started rechecking all my torrents (not fun with multiple 100+ gb torrents loaded).

edit: tested 1.6.1 (build 490), and it did not drop speeds at the same pressure as 2.0 rc2.

[Switeck]

Your pictures still show cache settings enabled that I said to disable.

Also see if you can increase cache size to 512 MB and take a couple screenshots as the cache fills up AND the moment it becomes filled. It's a shame that uTorrent cannot show the cache status and speed graph at the same time, so just show the speed graph and tell me what the cache fill level is at that time.

Or make a couple arrows on a single longer speed graph.

"cache disabled"

"cache enabled"

"cache filled"

"cache disabled" (again!)

Proof like this is needed so the developers can track down the problem.

[zyrobs]

http://img136.imageshack.us/img136/1948/utorrent6.png

The cache doesn't even get to fill up. There are no disk overload messages at all (I don't even know where to look for them, since I never saw one ever!). It just hangs up at one point, like if something was stalling all disk reads. All read statistics counters are completely frozen.

It usually takes a little while for this bug to kick in, which is why I'm not going to make pictures on when I turned cache option x on/off. It is difficult to monitor this efficiently. The sub-options under read caching have zero effect, by the way.

The "disable windows caching" options seem to be related to the issue. I did this:

- had read caching disabled. Write caching enabled (with both sub-options enabled). Windows caching was disabled (as in, both checkboxes were ticked). Reduce memory was disabled, no override memory. Max speeds on torrents.

- unticked the windows read caching box. This causes memory usage of Windows (not utorrent) to become erratic as observed by the task manager. Obviously because Windows was caching disk reads itself.

- enabled utorrent caching of disk reads.

- The bug does not happen for minutes.

- Started up MyDefrag on my boot partition: no torrents are loaded from there, and the swapfile is on another physical hdd, which again has no torrents running. Normally, this should NOT affect utorrent, but it in fact kills utorrent speeds as soon as MyDefrag touches the hdd, by triggering the bug.

HOWEVER, with the "disable windows read cache" box unticked, no speed drops happened.

So, if I do not disable Windows caching, the bug doesn't seem to happen!

If I re-disable the windows caching (tick the boxes), the bug will eventually happen again... both on it's own, or if it is "stimulated". Also, once the bug happened, unticking the "disable windows cache" will not immediately fix the bug. Disk reads will still need to climb back up by themselves.

My conclusion therefore is that there are conflicts in the way utorrent interacts with the windows read caching, causing read stalls in every part of utorrent: no reading from the cache, no reading from hdd, even file hashing is halted.

(and yes, I did try all the other options you mentioned, but no other combination had any effect at all, so please excuse me for not talking about every possible permutation in detail with pictures - it takes time and a lot of patience to test this).

On a related note, I used the term of ticking and unticking the box, because saying "disabled this option" could've caused some confusion due to the double negative used (disabled the cache disabling, etc). I hope that my description over the used options was clearer this way.

[Switeck]

My bad.

Uncheck Reduce memory usage.

Uncheck turn off read cache if upload speed is slow. (Upload speed should not be slow in your case!)

Uncheck remove old blocks from cache. (This is probably why uTorrent's cache never fills up!)

[zyrobs]

I've tried that, and it made no difference.

[Switeck]

It was a longshot...

Ok, Process Explorer utorrent.exe DLL list (1st link in my signature, very last of last section.)

[zyrobs]

Process PID CPU Description Company Name Start Time Page Faults Private Bytes Peak Private Bytes Working Set Peak Working Set

System Idle Process 0 n/a 0 0 K 0 K 24 K 0 K

Interrupts n/a Hardware Interrupts n/a 0 0 K 0 K 0 K 0 K

DPCs n/a Deferred Procedure Calls n/a 0 0 K 0 K 0 K 0 K

System 4 19:50:52 2009.12.27. 39 754 0 K 0 K 80 K 17 432 K

smss.exe 512 Windows Session Manager Microsoft Corporation 19:50:52 2009.12.27. 285 292 K 340 K 152 K 732 K

csrss.exe 580 Ügyfél-kiszolgáló futásidejű folyamat Microsoft Corporation 19:50:58 2009.12.27. 4 846 1 712 K 1 720 K 1 116 K 5 160 K

csrss.exe 644 Ügyfél-kiszolgáló futásidejű folyamat Microsoft Corporation 19:51:01 2009.12.27. 527 905 3 408 K 42 268 K 8 884 K 24 496 K

wininit.exe 652 Windows-indítóalkalmazás Microsoft Corporation 19:51:01 2009.12.27. 2 528 1 416 K 1 484 K 184 K 4 224 K

services.exe 692 Szolgáltató és vezérlő alkalmazás Microsoft Corporation 19:51:01 2009.12.27. 23 483 2 728 K 2 904 K 1 824 K 6 888 K

svchost.exe 896 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:07 2009.12.27. 863 301 3 204 K 3 360 K 3 092 K 6 608 K

unsecapp.exe 2224 Sink to receive asynchronous callbacks for WMI client application Microsoft Corporation 19:52:02 2009.12.27. 155 140 2 800 K 2 828 K 1 628 K 6 500 K

WmiPrvSE.exe 2292 WMI Provider Host Microsoft Corporation 19:52:02 2009.12.27. 47 777 3 692 K 4 352 K 2 040 K 6 080 K

dllhost.exe 6024 COM Surrogate Microsoft Corporation 23:37:27 2009.12.30. 1 374 1 484 K 1 484 K 4 776 K 4 776 K

svchost.exe 956 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:07 2009.12.27. 37 416 3 908 K 3 944 K 3 188 K 6 836 K

svchost.exe 1052 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:08 2009.12.27. 67 883 14 432 K 15 164 K 6 256 K 12 968 K

audiodg.exe 1196 Windows hangeszközgrafikon-elkülönítés Microsoft Corporation 19:51:10 2009.12.27. 410 155 30 832 K 35 572 K 20 924 K 29 972 K

svchost.exe 1096 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:08 2009.12.27. 103 895 9 400 K 48 376 K 3 380 K 11 532 K

dwm.exe 1704 Asztali ablakkezelő Microsoft Corporation 19:51:14 2009.12.27. 5 145 596 42 492 K 54 208 K 67 148 K 101 296 K

svchost.exe 1116 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:08 2009.12.27. 846 722 54 384 K 194 740 K 15 648 K 197 484 K

taskeng.exe 1648 Feladatütemező motor Microsoft Corporation 19:51:14 2009.12.27. 30 734 14 276 K 41 332 K 7 388 K 13 224 K

taskeng.exe 1792 Feladatütemező motor Microsoft Corporation 19:51:15 2009.12.27. 28 943 2 200 K 2 276 K 2 228 K 6 368 K

svchost.exe 1212 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:10 2009.12.27. 4 129 3 300 K 3 468 K 2 704 K 5 972 K

SLsvc.exe 1232 Microsoft Szoftverlicencelési szolgáltatás Microsoft Corporation 19:51:10 2009.12.27. 15 748 7 456 K 13 344 K 1 524 K 15 664 K

svchost.exe 1300 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:10 2009.12.27. 29 504 4 868 K 4 984 K 3 416 K 8 552 K

svchost.exe 1380 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:11 2009.12.27. 65 046 19 884 K 20 908 K 9 160 K 17 232 K

svchost.exe 1504 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:11 2009.12.27. 65 528 8 508 K 83 616 K 2 988 K 69 424 K

nlsvc.exe 808 NetLimiter 2 service Locktime Software 19:51:45 2009.12.27. 971 668 5 892 K 8 060 K 4 068 K 9 168 K

NLClient.exe 1616 NetLimiter 2 Client Locktime Software 19:51:53 2009.12.27. 4 481 437 43 732 K 169 368 K 16 224 K 44 700 K

svchost.exe 1180 Windows-szolgáltatások gazdafolyamata Microsoft Corporation 19:51:46 2009.12.27. 1 471 1 676 K 1 704 K 184 K 4 584 K

ADSL Autoconnect.exe 248 ADSLAutoconnect 19:51:48 2009.12.27. 92 149 8 132 K 8 160 K 956 K 6 216 K

DynUpSvc.exe 3036 DynDNS® Updater Service Dynamic Network Services, Inc. 19:53:49 2009.12.27. 9 967 5 204 K 5 224 K 2 492 K 6 052 K

UI0Detect.exe 5160 Interaktív szolgáltatások észlelése Microsoft Corporation 16:02:45 2009.12.28. 2 375 3 332 K 3 332 K 2 056 K 6 528 K

atiesrxx.exe 2212 AMD External Events Service Module AMD 18:15:31 2009.12.29. 921 996 K 996 K 280 K 3 148 K

atieclxx.exe 5964 AMD External Events Client Module AMD 18:15:31 2009.12.29. 1 998 2 384 K 2 384 K 1 532 K 4 660 K

lsass.exe 740 A helyi biztonsági szervezet folyamata Microsoft Corporation 19:51:02 2009.12.27. 485 580 4 092 K 4 264 K 3 300 K 8 104 K

lsm.exe 748 Helyi munkamenet-kezelő szolgáltatás Microsoft Corporation 19:51:02 2009.12.27. 2 822 1 956 K 2 004 K 1 104 K 4 012 K

winlogon.exe 716 Windows bejelentkeztető alkalmazás Microsoft Corporation 19:51:01 2009.12.27. 3 839 2 128 K 3 132 K 216 K 6 912 K

explorer.exe 1756 Windows Intéző Microsoft Corporation 19:51:15 2009.12.27. 3 403 855 43 536 K 78 444 K 39 488 K 99 256 K

Amoumain.exe 1916 Amoumain A4Tech Co.,Ltd. 19:51:18 2009.12.27. 4 886 2 968 K 3 060 K 1 916 K 6 608 K

daemon.exe 1924 Virtual DAEMON Manager DT Soft Ltd. 19:51:18 2009.12.27. 3 010 2 076 K 2 124 K 1 020 K 6 444 K

atitray.exe 1932 ATI Tray Tools Ray Adams 19:51:18 2009.12.27. 31 040 41 108 K 51 288 K 3 508 K 40 204 K

bpftpserver.exe 1948 BulletProof FTP Server (http://www.bpftpserver.com) DigitalCandle, Inc. 19:51:20 2009.12.27. 14 781 7 700 K 7 768 K 4 844 K 13 872 K

taskmgr.exe 1980 Windows Feladatkezelő Microsoft Corporation 19:51:21 2009.12.27. 213 134 4 168 K 43 572 K 4 788 K 15 312 K

foobar2000.exe 1696 foobar2000 22:48:27 2009.12.30. 73 057 50 500 K 51 904 K 50 304 K 57 712 K

iexplore.exe 2600 Internet Explorer Microsoft Corporation 23:33:47 2009.12.30. 23 362 7 488 K 8 020 K 25 448 K 31 664 K

iexplore.exe 5532 Internet Explorer Microsoft Corporation 23:33:47 2009.12.30. 146 182 65 640 K 83 364 K 73 048 K 87 900 K

explorer.exe 6092 Windows Intéző Microsoft Corporation 23:34:26 2009.12.30. 18 040 16 352 K 17 532 K 28 272 K 29 284 K

WinRAR.exe 3364 WinRAR archiver Alexander Roshal 23:37:32 2009.12.30. 5 382 8 872 K 10 076 K 15 452 K 15 700 K

procexp.exe 4348 Sysinternals Process Explorer Sysinternals - www.sysinternals.com 23:37:34 2009.12.30. 3 261 7 004 K 7 052 K 10 396 K 10 396 K

utorrent.exe 2512 µTorrent BitTorrent, Inc. 3:52:04 2009.12.30. 426 477 101 988 K 561 860 K 56 292 K 570 928 K

Process: utorrent.exe Pid: 2512

Name Description Company Name Version

actxprxy.dll ActiveX Interface Marshaling Library Microsoft Corporation 6.0.6001.18000

ADVAPI32.dll Speciális 32 bites Windows API Microsoft Corporation 6.0.6002.18005

Amhooker.dll Amhooker.dll A4Tech Co.,Ltd. 7.80.1.4

apphelp.dll Alkalmazáskompatibilitási ügyfélkönyvtár Microsoft Corporation 6.0.6002.18005

ATL.DLL ATL Module for Windows XP (Unicode) Microsoft Corporation 3.5.2284.2

C_1252.NLS

CLBCatQ.DLL COM+ Configuration Catalog Microsoft Corporation 2001.12.6931.18000

COMCTL32.dll Felhasználói élmény vezérlőinek kódtára Microsoft Corporation 6.10.6002.18005

comctl32.dll.mui Felhasználói élmény vezérlőinek kódtára Microsoft Corporation 6.10.6000.16386

comdlg32.dll Common Dialogs DLL Microsoft Corporation 6.0.6002.18005

comsvcs.dll COM+ Services Microsoft Corporation 2001.12.6932.18005

dhcpcsvc.DLL DHCP-ügyfélszolgáltatás Microsoft Corporation 6.0.6002.18005

dhcpcsvc6.DLL DHCPv6-ügyfél Microsoft Corporation 6.0.6002.18005

DnsApi.dll DNS-ügyfél API DLL-je Microsoft Corporation 6.0.6002.18005

DUser.dll Az Internet Explorer felhasználói felületének motorja Microsoft Corporation 6.0.6001.18000

FirewallAPI.dll Windows tűzfal API Microsoft Corporation 6.0.6001.18000

GDI32.dll GDI Client DLL Microsoft Corporation 6.0.6002.18005

GPAPI.dll Csoportházirend-ügyfél API Microsoft Corporation 6.0.6002.18005

hnetcfg.dll Otthoni hálózat konfigurációkezelője Microsoft Corporation 6.0.6001.18000

ieframe.dll Internet Explorer Microsoft Corporation 8.0.6001.18865

iertutil.dll Run time utility for Internet Explorer Microsoft Corporation 8.0.6001.18865

imageres.dll Windows Image Resource Microsoft Corporation 6.0.6000.16386

imageres.dll.mui Windows Image Resource Microsoft Corporation 6.0.6000.16386

IMM32.DLL Multi-User Windows IMM32 API Client DLL Microsoft Corporation 6.0.6002.18005

IPHLPAPI.DLL IP Helper API Microsoft Corporation 6.0.6002.18005

kernel32.dll Win32 kernel mag komponens Microsoft Corporation 6.0.6002.18005

locale.nls

locale.nls

LPK.DLL Language Pack Microsoft Corporation 6.0.6002.18051

MSCTF.dll MSCTF kiszolgáló DLL Microsoft Corporation 6.0.6002.18005

MSVCR90.dll Microsoft® C Runtime Library Microsoft Corporation 9.0.30729.4148

msvcrt.dll Windows NT CRT DLL Microsoft Corporation 7.0.6002.18005

mswsock.dll Microsoft Windows Sockets 2.0 szolgáltató Microsoft Corporation 6.0.6002.18005

napinsp.dll E-mail elnevezési köztes szolgáltató Microsoft Corporation 6.0.6001.18000

NLAapi.dll Network Location Awareness 2 Microsoft Corporation 6.0.6001.18000

npmproxy.dll Network List Manager Proxy Microsoft Corporation 6.0.6000.16386

NSI.dll NSI User-mode interface DLL Microsoft Corporation 6.0.6001.18000

ntdll.dll NT réteg DLL Microsoft Corporation 6.0.6002.18005

NTMARTA.DLL Windows NT - MARTA-szolgáltató Microsoft Corporation 6.0.6002.18005

ole32.dll Microsoft OLE for Windows Microsoft Corporation 6.0.6002.18005

oleaut32.dll Microsoft Corporation 6.0.6002.18005

pnrpnsp.dll PNRP-névtérszolgáltató Microsoft Corporation 6.0.6001.18000

PROPSYS.dll Microsoft tulajdonságrendszer Microsoft Corporation 7.0.6002.18005

PSAPI.DLL Process Status Helper Microsoft Corporation 6.0.6000.16386

raphook.dll

rasadhlp.dll Remote Access AutoDial Helper Microsoft Corporation 6.0.6000.16386

RPCRT4.dll Távoli eljáráshívás – futásidejű Microsoft Corporation 6.0.6002.18024

rsaenh.dll Microsoft Enhanced Cryptographic Provider Microsoft Corporation 6.0.6002.18005

SAMLIB.dll SAM Library DLL Microsoft Corporation 6.0.6002.18005

Secur32.dll Security Support Provider Interface Microsoft Corporation 6.0.6002.18051

SETUPAPI.dll Windows Setup API Microsoft Corporation 6.0.6002.18005

SHELL32.dll Windows rendszerhéj - közös DLL Microsoft Corporation 6.0.6002.18005

shfolder.dll Shell Folder Service Microsoft Corporation 6.0.6000.16386

SHLWAPI.dll Shell Light-weight Utility Library Microsoft Corporation 6.0.6002.18005

slc.dll Szoftverlicencelési ügyfél dinamikus kódtára Microsoft Corporation 6.0.6002.18005

SSDPAPI.dll SSDP Client API DLL Microsoft Corporation 6.0.6000.16386

SXS.DLL Fusion 2.5 Microsoft Corporation 6.0.6001.18000

upnp.dll UPnP Control Point API Microsoft Corporation 6.0.6001.18000

urlmon.dll OLE32 Extensions for Win32 Microsoft Corporation 8.0.6001.18865

USER32.dll A Windows többfelhasználós USER API-jának ügyféloldali DLL-je Microsoft Corporation 6.0.6002.18005

USERENV.dll Userenv Microsoft Corporation 6.0.6002.18005

USP10.dll Uniscribe Unicode script processor Microsoft Corporation 1.626.6002.18005

utorrent.exe µTorrent BitTorrent, Inc. 2.0.0.17668

uxtheme.dll Microsoft UxTheme függvénytár Microsoft Corporation 6.0.6001.18000

VERSION.dll Version Checking and File Installation Libraries Microsoft Corporation 6.0.6002.18005

WINHTTP.dll Windows HTTP-szolgáltatások Microsoft Corporation 6.0.6002.18096

WINNSI.DLL Network Store Information RPC interface Microsoft Corporation 6.0.6001.18000

winrnr.dll LDAP RnR Provider DLL Microsoft Corporation 6.0.6002.18005

WLDAP32.dll Win32 LDAP API DLL Microsoft Corporation 6.0.6002.18005

WS2_32.dll Windows Socket 2.0 32 bites DLL Microsoft Corporation 6.0.6001.18000

wship6.dll Winsock2 segítő kódtár (TL/IPv6) Microsoft Corporation 6.0.6001.18000

wshtcpip.dll Winsock2 segítő kódtár (TL/IPv4) Microsoft Corporation 6.0.6001.18000

[Greg Hazel]

You could try running Performance Monitor to see what's going on while uTorrent is stalling. I'd be interested to know if uTorrent has a lot of disk IO during that period, or if something else does.

Otherwise, since I don't have the good fortune of owning a line which can upload at several MB/s, would anyone with this issue be willing to provide RDP access so I could diagnose it?

[zyrobs]

I'm not too keen on opening up a remote desktop connections.

But if you can tell me how to make any kind of debug logs, or what I need to monitor specifically (and with what), I'd be happy to provide all the info needed to resolve this. What Performance Monitor do you mean, the one built in Vista? What kind of info do you want me to monitor on it?

Though, I can rarely max out my line as much as I do now (seasons freeleech, etc)...

[Greg Hazel]

There are two tools which might be useful here:

1) "Resource Monitor", perfmon.exe /res

Just watch disk read throughput while uTorrent is stalled, and see which application is responsible if there is any, or if the disk is idle during this period.

2) "Performance Monitor", perfmon.exe /sys

Monitor these values:

http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/sag_mpmonperf_19.mspx?mfr=true

and see if throughput is high, or if the "Current Disk Queue Length" is high during the stalling period. If you could correlate these graphs with the uTorrent graphs that would be helpful.

If need-be, I'll make a build which adds additional logging, based off the results from those two applications.

[kidg21]

I know that this is not a very impressive solution to the speed fluctuations but I "downgraded" from 2.0 to 1.8.5 and everything is working like it was before I installed 2.0.

In case this helps...

[Greg Hazel]

I know that this is not a very impressive solution to the speed fluctuations but I "downgraded" from 2.0 to 1.8.5 and everything is working like it was before I installed 2.0.

In case this helps...

Are you sure your problem is related to the disk cache as well? Other users reporting here claim 1.8.5 behaves the same way.

[zyrobs]

Ah, you meant those two. (my OS is not english, so I wasn't sure if you meant the built-in vista monitors)

http://img191.imageshack.us/img191/8413/utorrent7.png

The jump in the disk usage column (2nd one) was when I opened, started, then closed down MyDefrag (this is how I forcefully trigger the bug). utorrent immediately stalled, and it resumed reading only after every "disk usage thread" under the disk usage row timed out/disappeared.

As for the Performance monitor, the Current Disk Queue Length stays at 1 when the bug is happening. Normally, it alternates between 1 and zero.

Not sure how much this helps.

A theory is that utorrent falls behind in reading if there is much disk activity in the system, and cannot resume the existing disk read threads - it will instead wait till they time out, and then start new reads. But, that doesn't explain why reads on a completely unrelated hdd can trigger this, also, I know jack squat about how disk reads are handled by utorrent or windows so this theory may even be a completely impossible scenario.

[Greg Hazel]

Ah, you meant those two. (my OS is not english, so I wasn't sure if you meant the built-in vista monitors)

http://img191.imageshack.us/img191/8413/utorrent7.png

The jump in the disk usage column (2nd one) was when I opened, started, then closed down MyDefrag (this is how I forcefully trigger the bug). utorrent immediately stalled, and it resumed reading only after every "disk usage thread" under the disk usage row timed out/disappeared.

As for the Performance monitor, the Current Disk Queue Length stays at 1 when the bug is happening. Normally, it alternates between 1 and zero.

Not sure how much this helps.

A theory is that utorrent falls behind in reading if there is much disk activity in the system, and cannot resume the existing disk read threads - it will instead wait till they time out, and then start new reads. But, that doesn't explain why reads on a completely unrelated hdd can trigger this, also, I know jack squat about how disk reads are handled by utorrent or windows so this theory may even be a completely impossible scenario.

Which "disk usage thread"s are you referring to, the one in Resource Monitor? uTorrent only has one actual disk thread, so if you see many requests, it's probably a sum of all the requests that occurred inside the polling interval (1 second, I believe). This is also why you only see the Current Disk Queue Length go between 0 and 1. If the polled list of requests gets down to only 1 request, that's the request that uTorrent was waiting on, and it's been waiting for at least a second (which is a long time). If a timeout did occur, uTorrent would stop the torrent with an error. Is it always the same disk, or even the same file? While this stalling is going on, can you save and read files from that disk / directory with notepad, or does that wait too?

[Switeck]

NetLimiter may be to blame for your problem:

http://forum.utorrent.com/viewtopic.php?pid=420142#p420142

Any clue what these are for?:

Amhooker.dll Amhooker.dll A4Tech Co.,Ltd. 7.80.1.4

raphook.dll

[zyrobs]

>Which "disk usage thread"s are you referring to, the one in Resource Monitor?

The ones in Resource monitor, the lines that say what files are utorrent reading, at what speeds, etc. Once all of them time out (disappear from resmon), utorrent continues.

>Is it always the same disk, or even the same file?

All my torrents are on the same hard disk right now. But, it also happens if I'm running torrents across multiple drives. It also happens if I'm only maxing out with relatively small torrents. The only common thing I can think of is that most if not all torrents I'm usually running have a piece size of 4mb or higher.

Every other application can read/write the disk, it is only utorrent that hangs up reads. Infact, utorrent can keep writing as well (if the downloads aren't too fast), only reads die off.

I've had a torrent capped at 1mbyte/s download, and it kept going even as the disk reads stalled. Though, after I set it back to unlimited speed (5-6mbyte usually, depending on ISP load, could go up to 11mbyte), disk writes stalled as well, and so did this downloading torrent. This torrent was only around 3gb, not even that big.

>NetLimiter may be to blame for your problem

I've tried disabling Netlimiter (both the application and the service), but the bug still happens.

Amhooker.dll is the mouse driver, raphook.dll is ati tray tools.

[Switeck]

So even with NetLimiter completely uninstalled the bug still happens?