64-bit OS and it's memory support

[Bloodfire]

While going through school and doing some assignments, I noticed as I was reading my textbook, it mentioned which 64-bit OS's support how much RAM as follows:

Vista Ultimate, Enterprise, and Business -- 128 GB
Vista Home Premium -- 16 GB
Vista Home Basic -- 8GB
XP Pro x64 -- 128 GB

The book was published just before Win7 was released so there isn't much info on that OS. Also keep in mind it does not mention information about Server OS's.

It was my understanding though that 64-bit systems don't have a memory ceiling so to speak, or it is very, very high. Is what the book stating true for a 64-bit OS, or is 128 GB really all the Windows OS can support?

[Kaisha]

10 seconds of Googlin' : http://msdn.microsoft.com/en-us/library/aa366778%28VS.85%29.aspx


Seems like the other ones are just software caps for the sake of increasing the value of the more expensive version assuming you need more than 8gb for some reason. But I don't know, it could be the way they're programmed also on the server-related releases.

[Bloodfire]

Bah, my brain is fried from doing so many quizzes, I got lazy. thx for the link Kaisha.

[Kohan]

Your question was already answered, but regardless, using anything besides Professional/Ultimate is for know-nothings anyway. The Home versions' supposedly "user-friendly" limitations are a tremendously unintuitive pain in the ass when you have to work around them.