If SER running at 1k threads is not enough, and i'd say even that is WAY to high, then it's time you get multiple copies of SER running on multiple different servers. Don't forget more copies of CB also.
Unless you have several hundred proxies to run such high threads, you're going to be losing more potential links than ser can build at such high threads.
Comments
Multiple copies are not a problem, the problem is to keep things organized and not split between 8 servers...