I’m wondering the same thing. I guess we just have to try it.
I have tried to test wp supercache. Works on my standard blog very well, on wpmu bp > buggy. Don´t know why 
Blank pages etc.
WPSC has a “don’t cache for logged in users” setting, which you might want to use given the nature of a BP site.
I’ve seen various people also recommending WP Object Caching, which can reduce the load on the DB server and might be worth looking into *if* your performance bottleneck is the DB… if it isn’t, then it could make matters worse. Use the page generation time and (to a lesser extent) the number of queries information that the default templates show in an HTML comment at the bottom of most templates to test your options both with and without whatever caching you put in.
Useful links: Overview of WP Object Cache from 2006 for an intro, various flavours of Object Cache (APC, eAccelerator, filesystem) (if you dig around you’ll also find one which works with memcached).
I tried adding object cache and super-cache and I don’t see any errors, but with object cache on I see my page creation time is higher. Is that normal?
Please read this BP Codex article:
Improving Performance
There are simply too many variables to give an iron-clad, standard approach that will work for every setup. As Simon states above, you need to test and experiment to see what tools and configurations work best given your specific setup.
I hope you weren’t replying to me because that was the article I first read and it doesn’t say.
@Lostdeviant
I was posting a general, “Here’s an article on the basics on improving BP performance.” I have no idea what you may have already read. My mind-reading skills are rusty. 
Super cache is not a good solution for BuddyPress since the pages are updating all the time and the cache becomes poisoned too quickly. Object cache is a much better approach.
What about Widget Cache? any thoughts on this?
consider to set a short GC time and don’t cache for logged in user alost exclude most active RSS feed path
Tested in different contain variation with turn-half-on supercache and turn off, site wide activity RSS is completely lost control while supercache is on.
Post new blog post: work fine
Post new forum topic/reply: random hours delay
New user registration: disappeared
When turn off supercahce, everything back to normal, i tried to exclude is_feed and several feed, /feed/, /activity/feed/ but no effect at all.
I’m using BP1.1.2 and 2.8.5.2 mu and supercache 0.9.7
@jeffsayre and all other users,
Im developing our new site right now, was looking for a cache plugin.
The option that Jeff gave us is by far the best option for WP & BP !
Improving Performance
At least try it, it’s worth it 
Cheers,
Aron
