> > back I see is the max RAM on i386 but perhaps I am wrong. 90 percent > > of our CPU load is Spamassassin. Disk I/O is likely a big bottle neck > > Are you using spamd? Yes, and it almost always on the top of top. > I ask, because me mate's system was rather busy, and it transpired he > wasn't. > > > Other than extra RAM, AMD-64 CPUs have more registers, and they work > best with 64-bit code, so for CPU-intensive work you should see better > performance with 64-bit Linux than with 32-bit. I still doubt if I move to 64 bit since its still considered beta by the web GUI I am using and I have no intention of porting 2000 email accounts plus a few websites to a new platform. Doing a admin/reseller backup and restore is going to be nasty enough. If I initially have 4G of RAM can I actually jump up to 8G later on i386 CentOS? Matt