64-bit

[ra_rav]

what is the difference between amd64 and ia64(intel) technologies?

[vijay_7287]

dunno exactly
but intel64's are two 32 bits stacked on the same die

and AMD64,its more integrated

this link gives a comparision performance wise
http://www.linuxhardware.org/article.../02/24/1747228[/list]

[siriusb]

IA64 is an intel 64bit instruction set used in Itanium and Itanium2. It is strictly for 64 bit processors. But it can run some 32bit code via emulation at an extreme performance loss.
AMD64 (or x86-64 or x64) is develoed by amd and used in it's athlon64 processors. This differs from ia64 in that amd64 can run 32 bit code while running 64bit OS with insignificant performance loss compared to a comparable 32bit processor. The intel version of this set is the Em64T thing.

[Kniwor]

Originally Posted by siriusb

IA64 is an intel 64bit instruction set used in Itanium and Itanium2. It is strictly for 64 bit processors. But it can run some 32bit code via emulation at an extreme performance loss.
AMD64 (or x86-64 or x64) is develoed by amd and used in it's athlon64 processors. This differs from ia64 in that amd64 can run 32 bit code while running 64bit OS with insignificant performance loss compared to a comparable 32bit processor. The intel version of this set is the Em64T thing.

Sorry, but u made a mistake here, although u are right about itanium, but in an A64 after installing 64bit OS, the performance of 32bit apps only imporves as compared to a 32bit OS, but is lower than 64bit app running on 64bit OS, so it's actually unfair to compare, because an A64 performs much better than an 32bit proc running 32 bit, the reason is other artitechtural changes made while introducing A64, and there are no 32bit processor with that fine artitechture to compare. (Changes like Hypertransport etc...)

So u can only guess and cant make an statement.

But an itanium is very poor at 32bit.

Originally Posted by vijay_7287

dunno exactly
but intel64's are two 32 bits stacked on the same die

there is nothing like this, all the A64 are 64bit processors, u are suggesting that intel 64bits are double core 32 bit processors, if this was the case they would have performed very nice in 32bit apps but this is not the case.....
this is totally absurd and please please slap the person who told this to you.

[siriusb]

Sorry, but u made a mistake here, although u are right about itanium, but in an A64 after installing 64bit OS, the performance of 32bit apps only imporves as compared to a 32bit OS, but is lower than 64bit app running on 64bit OS, so it's actually unfair to compare, because an A64 performs much better than an 32bit proc running 32 bit, the reason is other artitechtural changes made while introducing A64, and there are no 32bit processor with that fine artitechture to compare. (Changes like Hypertransport etc...)

So u can only guess and cant make an statement.

You maybe right because the amd64 introduces extra registers and added memory addressablity. But if u can find/make a comparable 32bit processor, the performance shuld be slightly lesser(in most cases) due to wow64 layer in a64.

[Kniwor]

yeah, and that's what i said, there's none to compare with..... anyhow i hope our discussion clears their doubts...

[ra_rav]

I ve a confusion regarding the EM64T from Intel. Is it really 64-bit like Itanium and Athlon64 or it is just a modification to existing 32-bit core, which is able to address the 64-bit memory addresses.

[siriusb]

EM64T is Intel's name for AMD64, and nothing more. Coz, obviously, they can't say they support Amd64 in their processors
And, if I remember correctly, x86-64 for now supports only 40bit (1TB) memory addressing and not 64bit. I think there's not much demand for higher capacities for now.