CPU. Licensing gives you a strong incentive to stick to single socket CPU designs. Multiple socket motherboards have hefty penalties for SQL 2005, as you need a license per CPU.
Memory. At the 2GB cutoff you have to move to Windows Server Standard from Wed Edition. After the 4GB cutoff you have to move to Windows Server Enterprise. Similar issue with SQL2005– after 4GB, you need to swith to Enterprise Edition. On the otherhand, the free SQL Express edition merely doesn’t use the extra memory.
CAL Counting. Some CAL counting scenarios are easy. Others are mind bogglingly complicated. So far, most people tend to search for licenses that don’t have legal or technological CAL limits because it is too hard to count users. Terminal Service and RDP servers are one are where CAL counting is enforce by license and technology, so CAL counting is important there. Everywhere else, there isn’t a CAL technological constriant. So when faced with counting users in a complex environment with some users using file shares, some using RDP occasionally, some printer users, some intranet IIS users, some internet IIS users, some people with local accounts, some with domain accounts, some with neither…I suspect most administors throw up their hands in frustration and stop trying to count unless there is a technological contraint.
Authentication. Your choice of authetication method can trigger CAL counting. This old technet page implies if you use integrated authentication and local users, you will trigger CAL counting. This means it is cheaper to write applications that avoid integrated authentication! This Oct 2000 article agrees:
“One more item of interest: Microsoft requires that you purchase a Client Access License (CAL) to enable a client to log on to a Microsoft server. Microsoft waives this requirement for Anonymous access to IIS servers, but if you authenticate a user against an account in User Manager, you need a CAL. If you plan to have many users authenticate to an IIS server, you can end up making a significant investment in CALs. If you use a non-Microsoft means of authentication, either custom or third party, you bypass this requirement but at the expense of not integrating with NTFS permissions.”
I couldn’t find anything that specificly mentioned domain accounts, but I supposed by analogy, if you use integrated authentication for your intranet application that will trigger CAL counting.