64-bit is not that great....
|Well, then I suggest that you read this:
90% of what consumer PC's do with see little or no benefit from 64bit processors. In fact they may actually run slightly slower as the system now has to push twice the amount of data through the processor whether the app needs to or not. If you do not have applications that need greater than 4GB of RAM or have data or file sizes larger than 4GB then 64 bit gets you nothing.
reason that AMD64 processers are so good is the on chip memory controller. This lowers memory latency by roughly 70%. That is huge.
I've been working with 64bit processors for 10 years now (unix sysadmin). A 32bit processor capable of say 1000mips is just as fast as a 64-bit capable of 1000mips. The difference is when you start getting to systems with 100's of GB of RAM and databases with huge working sets. 32-bit systems simply cannot do that, so you go 64bit.
What is important about 64bit x86 is that it means that PC servers can now start eating into the very high end of the server market. Clusters of low end 1U x86 servers can already match the performance of "big iron" at a fraction of the cost. But they are not easy to deploy large business databases on especially if you have old school dba's. 64-bit 8-32way x86 servers means you can host large databases the "old way" and still get access to large memory pools and still do it at a fraction of the cost of "big iron".
Its bad news for Sun and is why Sun is frantically moving to AMD and becoming a "software/services company". And its why IBM shares common chassis, components and system boards between their x445 x86 servers, their Power5 servers and their Power5 AS400 servers. IBM positioned themselves to go either way.
64 bit is of marginal value to the desktop until memory requirements exceed 4Gb or if 64bit gets added "free" to the processors. Its not a "must have" feature.