Recently I discussed the software limitations within SharePoint with a Microsoft technician and he reminded me about this great Technet article that I almost had forgot about or looked at for quite some time:

http://technet.microsoft.com/en-us/library/cc262787.aspx

If you have not seen it before I recommend you to read it. It’s worth a look each time you design a new environment. I especially like the diagrams MS have made for us.