[geeks] Business Decision Help, Please

[Joshua Boyd]

On Fri, Jan 18, 2008 at 09:57:47AM -0500, nate at portents.com wrote:
> > Anyone upgrade a 2.16 GHz MBP to 4 Gigs? (Crucial says 3072 is max.)
> 
> Pre "Santa Rosa" Intel mobile chipsets didn't support mapping the I/O
> space above the 4GB physical mark, so you end up with I/O space consuming
> physical address space, and losing that physical address space (i.e. it
> won't hurt anything to install 4GB, but you won't be able to use it all). 
> It was a bit of a daft oversight in my opinion, since Intel has supported
> re-mapping the I/O space on other (non-mobile) chipsets well before Santa
> Rosa.

I don't know about on the MacBook, but in Mini's there are reports that
installing 4 gigs will boost memory performance.  So you can still only
use 3 gigs, but the memory is performing better.