Author: Eugene Nalimov
Date: 15:36:51 08/14/03
Go up one level in this thread
Martin, I'd recommend you not to read articles on the web site that published the information you quoted. Once again: IA-64 can natively execute all user-level x86 instructions, though on both Itanium1 and Itanium2 they are executed slow. Thanks, Eugene On August 14, 2003 at 18:07:17, Martin Andersen wrote: >On August 14, 2003 at 17:46:03, Eugene Nalimov wrote: > > >>>>32 bit programs can run on a 64 bit computer. >>> >>>Yes, but 32 bit programs will run slowly on a pure 64 bit >>>computer like Intel Itanium, because the system needs to emulate >>>32 bit in software. >> >>Exactly the other way. On Itanium2 software emulation of x86 is much faster than >>direct hardware support :-) >> >>Thanks, >>Eugene >> > >You are wrong. > >Quote from www.anandtech.com : > > >In the past, Intel had been the ones to extend the x86 ISA (Instruction Set >Architecture) beyond its 8-bit foundation. But once Intel hit 32-bit and started >to look towards the future and 64-bit microprocessors, they wanted to rid >themselves of the somewhat bulky x86 ISA and move towards something much more >robust - and thus, IA-64 was born. > >The IA-64 ISA is significantly better than the x86 ISA in a number of ways, but >the discussion of IA-64 is beyond the scope of this article as we're here to >focus on x86. The biggest problem with the IA-64 ISA and thus IA-64 >microprocessors is the lack of native x86 compatibility, effectively keeping >IA-64 processors from running over two decades worth of software. Intel >recognized this and equipped their IA-64 processors (Itanium, Itanium 2, etc…) >with an x86-to-IA-64 decoder, that takes x86 instructions and decodes them into >IA-64 instructions. This decoder is not the most efficient decoder nor is it the >best way to run x86 code (the best way would be to run it natively on an x86 >processor), and thus the Itanium and Itanium 2 offer quite poor performance >under x86 applications. > >http://www.anandtech.com/cpu/showdoc.html?i=1815&p=5 > > >Martin.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.