After posting earlier about performance problems with Dropbox, I got an email from Arash Ferdowsi, the Founder/CTO of the company, saying there is a new version in the final stages of testing. He suggested it might help with some of the problems. 

He wrote: "I recommend trying the latest release candidate of dropbox. it's been incubating for the last 9 months and we're planning to release it in the next 2-3 weeks. it's much better at handling large file sets and uses much less cpu/memory. additionally, it's a lot more aggressive about pruning the dropbox cache (the build you're on only clears it when the dropbox process reboots while the new build clears it every 3 days)." 

http://forums.dropbox.com/topic.php?id=27419&replies=146  

I asked if I could install the software on just some of the machines here, and he said yes, with a caveat. "0.8 now supports syncing of the executable bit and some other xattr data. if you're running a mix of 0.7 and 0.8 clients, this metadata won't sync properly." 

I'm installing the new release on the server that's suffering the most, and on one or two other machines. I will of course report the results.  

Update: I've tried installing the new software on two machines and both installs have frozen at this point. I'm going to leave the installer running on this machine for a while and see what happens. 

Update: A couple of hours later, I was able to get it to install on one of the machines by first uninstalling then re-installing the app. This meant relinking the account, a slow process, but there was an upside -- I stumbled across the new Selective Synch function. This is going to make a big difference. It allows me to push content out through Dropbox that I might only need on one or two other machines, without adding overhead for the others. Nice! 

Update: Why does Dropbox download so slowly? 5K/sec. I have no bandwidth constraints in the prefs. See the screen shot.