The computer that I was attempting to view the movie on has one Pentium 4 3.20 GHz CPU with hyperthreading, and 2 GB of RAM.

Hyperthreading separates the processor into two logical processors.  They do share some of the pipe, so it’s not quite as good as two actual logical processors.  The thing about hyperthreading though, is instead of one 3.20 GHz processor, I effectively get two 1.70 GHz processors.

Well, a 1.70 GHz processor isn’t enough to decompress the file in real time.  So, I had to turn off hyperthreading in the computer’s setup menu to get a single logical CPU that runs at 3.20 GHz, providing all of the CPU power to the movie player process.

Unfortunately, even that wasn’t quite fast enough, but it was close.  I haven’t noticed any decrease in performance since I’ve turned off hyperthreading, and I’d like to keep the CPU power on hand for the next time I need it.  So, I’m leaving hyperthreading off.

In my normal use, I’d rather have one process get finished very quickly, than have two processes take longer and finish at the same time.  I usually just have one process that I’m waiting on.