Robert C Wittig wrote: > Siju George wrote: > > > I thought by running an amd64 kernel will get me twice the > speed than > > an i386 on an amd64 machine since one is 64 bit processing and the > > other is just 32 bit :-( > > > > 64 bit processors (combined with 64 bit capable operating > systems) have > the ability to address more RAM than 32 bit processors > because 64^2 is a > much larger number than 32^2... lots more RAM addresses).
Actually 2^64 vs 2^32 (64^2 is 2^7, 64 is 2^6, 32 is 2^5) Other things equal, 64-bit should take twice as long because it takes 64 bits to do anything instead of 32 bits. Not really that simple, because accessing 32 bits can involve 1) accessing the 64 bits that the 32 bits are in. 2) selecting the appropriate 32 bits of the 64 bits. > > This does not speed things up, though, until you run out of RAM, and > start having to access the swapfile. The 64-bits does affect how big the swap file can be without resorting to Rube Goldberg contraptions to identify what is what. > > The processor's speed... MHz, GHz, etc., will determine how fast the > processor itself can process instructions. > > > -- > -wittig http://www.robertwittig.com/ > http://robertwittig.net/ > http://robertwittig.org/ > .
