On 8/4/07, Ron Johnson <[EMAIL PROTECTED]> wrote: > On 08/04/07 12:53, Andrew J. Barr wrote: > >> a) What are the pros and cons in switching to 64 bit mode? > >> - Is it faster? > > > > Yes. Unlike true 64-bit architectures like PowerPC, there is a penalty > > for executing 32 bit code on amd64/em64t processors. > > Penalty? Absolutely fscking not!!!! The A64 processes 32 bit code > at a similar speed to "regular" Athlon CPUs.
Do you have any sources for this? I remember quite distinctly seeing on a mailing list, I think it was debian-powerpc in fact, that the only reason that AMD64 operating systems have an all-64-bit user land is because there is a penalty for executing 32-bit code, one which is not present on other true 64-bit architectures. 64-bit code /does/ use more memory, so it is advantageous to have a mixed userland if you can afford it--e.g. only compiling applications that will benefit from 64-bit into 64-bit executables. This is what the OSes for other 64-bit architectures do. Perhaps the penalty is only under a 64-bit kernel... -- Andrew Barr We matter more than pounds and pence, your economic theory makes no sense... -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
