> Download Accelerator uses four threads while HTTrack
> has a selection up to 32 threads.  That means that
> your Download Accelerator is eight times slower at
> maximum selected settings, so I would not use it.  
> 
> I was also able to type "50" into the selection line
> for HTTrack's "Number of connections" setting,
> though I don't know if HTTrack would keep that
> setting.  Running more than 10 simultaneous threads
> will probably get you disconnected from the web
> server, if the webmaster did his/her job, or, if
> they didn't, may even crash the server that you are
> trying to mirror.  
> 
> I often run a mirror over only two to four threads
> to make sure that I don't "hog" the server too much.
>  Generally, I don't think it makes much difference
> whether one uses four threads or 40, since the
> connection is running close to maximum at four
> threads, anyway.