On 06/18/2010 04:05 PM, Chris Adams wrote: > Once upon a time, Jerry Feldman<gaf@xxxxxxx> said: >> But, in my experience with 64-bit going back 16 >> years there are some applications that will run faster if built for >> 32-bit and some will run faster if built for 64-bit. > In the specific case of i386 to x86_64, you get better performance for > 64 bit in many more cases because of the larger register set in x86_64. > This isn't the case with some other architectures (e.g. SPARC or PPC), > but is why 64 bit on Intel/AMD architectures is almost always a "win" > compared to 32 bit on the same CPU. While this is true. But, my benchmarks were actually done on both an IA64 box as well as x86_64 and x86 boxes. I've also done some limited testing on HP-UX. In general on x86_64 architectures you are almost always better off with a 64-bit OS, as you mentioned the additional registers and memory access is linear. In the cases of Sparc and PA-Risc, the chips were really 32-bit chips upgraded to 64-bit. The IA64 and Digital Alpha chips were designed for 64-bits. I don't think the IA64 chip will ever be a desktop chip, but AMD and Intel still are figuring out how to breathe life into them. However there are some applications that are so 32-bit dependent that they would require a full rewrite to go to 64-bit. -- Jerry Feldman<gaf@xxxxxxx> Boston Linux and Unix PGP key id: 537C5846 PGP Key fingerprint: 3D1B 8377 A3C0 A5F2 ECBB CA3B 4607 4319 537C 5846 -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
