Don't ya need UPnP port mapping if randomizing port each start? I use it as a another means to get around my ISP shaping it's bandwidth. If not randomizing ports, yea, best to open ports manually.
Something else people might want to try is disabling Windows Firewall, if haven't already. That is if already using the router's firewall. DMZ is dangerous.
I don't have a 100mbit connection. Just the average 20/2. No problems when having enough peers for both up and down. Getting max on private trackers. But modifying the disk cache settings benefits everyone when using a large number of torrents. I have one hard drive dedicated to downloads and torrents. Whenever I copy from it, it's noticeably slow. After modifying the disk cache, like posted in this thread, my disk copy/move speed went from around 20 MB/s to 90 MB/s; same speed as with my other drives. Always suspected the torrent usage was the cause. Thanks.
Also set uTorrents Upload and Download caps to unlimited.
Doing that is not recommended. When your up bandwidth is saturated, your entire connection becomes a great deal slower. In particular, your download slow to a crawl. And, of course, when you're torrenting enough stuff, your up bandwidth is pretty much constantly maxed.
Ideally, as a rule of thumb, up should always be capped to 80% of your actual bandwidth limit. If you let uTorrent figure out your network's speed when you first start it up after a fresh install, it will do that automatically as well.
Another way to look at it: You would rather the throttling be done at your computer, than having your ISP do it. The ISP tends to choke everything. Also downloading requires a small amount of upload for communication, which it could be waiting if upload is choked.
But you can use unlimited if using QoS. Optimal for when having multiple apps using the bandwidth.
