Scotteq - Not True, Computer will see all 4 gigs, AND a 32 bit operating system WILL address ALL 4 gigs, it is just that only 3.2 give or take .2 will be availible for program usage.
Please read:
www.dansdata.com/askdan00015.htm
support.microsoft.com/kb/929605
In General.
The MIMO's remapped to the top of the four gogs MAY (Do not know) resulat in a small performance boast. Programs/operating systems have to access this code NO MATTER where it resides. With less than 4 gigs, where does this code reside, in BIOS, or in swap file. A "Call" to bios or swap file would be slower than if in memory (ie Memory that was remapped to HiMem in the OLD Dos days - 604K -> 1 Meg).
Next question, Is there a peformance booast goning from a 4 gig 32 bit system to a 4 gig 64 Bit system, I think not. The real advantage of the 64 bit operating system is when MORE than 4 gigs is used, and then it is program specific.
THIS IS NOT a slam againts 64 bit OP systems. They have there place, and eventially majority will migrate there. However, Advocates should also admit it is not "the greatest thing since sliced bread" for every one. I for one (I'm the exception) would have to fork out about 2 grand to update Pre-XP orcad and another program - and this is not worth it.