utorrent total dl speed mysteriously cuts off at 1.6Mb/s

As i wasn't around last week i had a little of catching up to do (aprox 3 Gb) and qued them up all at once. After 5 torrents started the total dl speed reached 1.6Mb/s and it didn't go over that even when queing a total of 19 torrents, instead the speed of the torrents that were already started were slowed down, like a download limit would do, but there isn't any set and i don't have any other software for limiting speed.
My connection has 15Mb/s downloadspeed (confirmed with a few speedtests) but no torrent (on other trackers either) has managed to go beyond that 1.6Mb/s.
Anyone any idea why this is? can this be because utorrent can't handle more, or the port it's going through doesn't allow or can't handle more, or does AVG 8.0 has anything to do with it (though i very much doubt that, it might be possible), or anything else anyone can think of?

thanks,
KS

What i also have noticed (and should have noticed a while sooner) is that my upload speed doesn't manage to get over 55 to 60 kbps, which is also a bit over 10% of my total upload speed (which is normaly 512 kbps). As speedtests through IE confirm that it should be aprox 10 times that, i would assume utorrent is limiting it, another program is limiting utorrent (can't be AVG, tried that), or windows somehow doesn't allow or can't handle it for some mysterious reason.

Isn't there anyone able and/or willing to help me with this? I think it would make a decent difference if i can seed 10 times faster then now...

i cant help but if this will make you feel better its all the same here. and all its because of this terrible thing called utorrent 1.8. dont know how and why but its it.

First, "Because of the very nature of BitTorrent, speeds are not guaranteed for any given torrent swarm. While you may get great speeds in one swarm, you might not in another. This is due to the fact that BitTorrent is a P2P protocol, so it depends on the upload speeds of the other peers you are connected to to generate your download speeds."
"the high (possible highest) and stable upload is a guarantee of getting best possible (for current torrents) speeds"

Second, "Some Internet Service Providers (ISP) block or throttle BitTorrent connections because of the high bandwidth it generates due to the sheer number of people using BitTorrent. Protocol Encryption combats this attack vector by hiding the fact that connections are BitTorrent connections. Some ISPs cannot distinguish an encrypted connection from any other random data connection, so they are unable to label it as a BitTorrent connection, and consequently, cannot block or throttle it for being a BitTorrent connection."

Enable Protocol Encryption

Third, read The Speed Guide and try and Test Your Configuration using the suggested links:
Speed Test Torrents:
https://distribution.openoffice.org/p2p/index.html
https://www.slackware.com/torrents/slackware-10.2-install-d1.torrent

sure we already know all this spasv, do we ks? the problem is 1.8 and nothing more. with 1.77 its alright at my home. in the office is the bad picture tho. 1.8 running here

First, I don't see anything about uTorrent 1.8.
Second, what I have seen about it was related to its connectivity.

As I already said I work with 1.8.1 Beta and there were 3 updates in a period of maybe less than 2 weeks.
So, the developer is working hard.

As to the connectivity I still cannot say for sure there is not problem anymore.
Testing wethear the port is beeing listen brings by different testers contradicting results.
I guess uTorrent 1.8.1 still has problem listenig the port fo incoming conections.

First thing is a bit logical, but i've had the problem an a lot of different swarms, and with the 1.8 version and previous versions, all cuts off on the same level, aprox 10% of my theoretical maximum limits.

Second thing i didn't know, might have a look at that, if i manage to find out where i could do that.

Hi,
have you found the answer?
If not here is something to consider.
It is called "TCP half open connections" in Windows and has been introduced by Microsoft to decrease the speed the viruses spread through Internet.
Not going into the details if you suffer a low download speed check out for the Event ID 4226  in the System log. (Start Event Viewer - for example: run/eventvwr.msc)
The presence of this event means there were 10 simultaneous uncompleted outbound TCP attempts. After that Windows reduces the rate at which new connections are established which results in limiting the download speed also.

The System log has about a hundred of those warnings with ID 4226 in it from the last 2 months.
I had already accepted it for a fact that it would be impossible to reach higher dl/ul speeds but that might still change :)
Do you know how to change this limit, or dissable this limitation alltogether? (if that's even possible).

Thanks a lot :)

I just came across this post from David Kaspar about that mysterious Event ID 4226 while going through a torrent optimization guide and remembered SpasV mentioning that here.

I have that Event 4226 several times a day, every day, so i checked with 'netstat -no | find "SYN"' in cmd.exe and had about 10 occurrences. The last number is the process ID of the application that windows is interfering with (I don't think you can see the PID in the normal taskmanager but I'm using Process Explorer (highly recommended, it's like Taskmanager on steroids, gives you a whole lot more control) in which you can) and that program was 10 times uTorrent (surprise surprise...).

You'll probbably have to dissable your AV before downloading the patch, because it tells you there's a hacker tool in there (obviously) but it works perfectly. You can use it to either set the limit to the recommended 50 or set it to whatever you want.

You're getting confused. You're downloading at 55-60kBps and your max speed is 512kbps. Notice the capital? 1kB = 8kb. 60kBps = 480kbps which is nearly your max speed.

kb = Kilobit, kB = Kilobyte. There's 8bits in a byte

A 1,500/512kbps ADSL Conenction can only download at 155kBps and Upload at 60kBps ~