Ubuntu 12.04, AMD64, 8GB RAM
The problem reported earlier regarding Tribler 5.9.15 using 100% of CPU has improved a lot with this new version, but is not gone. It just takes longer to happen.
For more background, see the later posts in http://forum.tribler.org/viewtopic.php?f=6&t=2023&p=4315#p4315
I could reproduce this problem consistently when downloading four files, taking up to 18 minutes to peg the CPU. Memory usage gradually climbs, about 2MB per minute, until the CPU pegs, when it climbs drastically. Must end the python process to bring CPU and memory usage down.
I am now doing a test with only one file downloading. It has been over an hour, and CPU has not pegged yet, and memory usage is climbing much more slowly. The problem seems to be dependent on how many files you are downloading.
Also had a problem with swift segfaulting once during these tests; reported in a separate thread.