Buffer Overflow plugged by AMD64.

[Hammer]

In relation BBRV’s to 'unmediated'  buffer overflows from http://amiga.org/forums/showthread.php?t=45060


ACCORDING TO A CBS commentator, AMD's Athlon 64 has code which Microsoft will employ in its Windows 64-bit operating system to plug buffer overflow exploits.

Mike Tarsala claimed that will give the edge to AMD over Intel, which has similar features in the Itanium microprocessor, but not in the Pentium 4.


It would seem that yet another non-X86 characteristics has been assimilated…

[dammy]

Hopefully this will allow the x86-phobic to come to an understanding that x86-64 isn't their grand dad's 8088.  If what I've been told is correct, x86-64 is more close to Alpha/MIPS then to Intel CPUs.

Dammy

[SamuraiCrow]

It's only good when it's in its 64-bit enhanced instruction set, not when it's in its x86 emulation mode.  :-(

[Wain]

Mike Tarsala claimed that will give the edge to AMD over Intel, which has similar features in the Itanium microprocessor, but not in the Pentium 4.

I'm confused by this...isn't the pentium 4 a 32-bit processor??
Why is the AMD 64 competing in the 32-bit market?

(Been out of the CPU loop awhile)

[Hammer]

Wain wrote:

Mike Tarsala claimed that will give the edge to AMD over Intel, which has similar features in the Itanium microprocessor, but not in the Pentium 4.

I'm confused by this...isn't the pentium 4 a 32-bit processor??
Why is the AMD 64 competing in the 32-bit market?

(Been out of the CPU loop awhile)

The main reason why AMD64(a.k.a K8) processors directly competes with Intel’s Pentium IV is due to;
1. full execution speed of X86-32 and X86-16 software investments.
2. Pricing segments.
3. K8 motherboard solutions.

K8 has slightly longer pipelines for clock speed bias compared to K7. In the long term, AMD's K8 architecture replaces K7 architecture.

Secondly, EV6 bus architecture (also use in the both K7 Athlon and DEC Alpha) has reached* its design limits i.e. DDR400 (PC3200). *without going to over clocking realm e.g. PC3500 level.

Windows XP AMD64 Edition (or Windows XP SP2) runs Win32(X86) software via WOW64 layer (Windows On Windows 64).

PS; At this time, the fastest AMD Athlon in terms of clock speed is the K7 Athlon @2.33Ghz (shipped with HP boxes). A slightly odd scenario since K8 Athlon FX-51 is clocked at 2.2Ghz...

[Hammer]

SamuraiCrow wrote:
It's only good when it's in its 64-bit enhanced instruction set, not when it's in its x86 emulation mode.  :-(

(Recalling from memory) K8 processor has basically 3 modes;
1. Legacy i.e. X86-16 and X86-32.
2. Mix mode i.e. X86-32 and X86-64(AMD64).
3. Pure AMD64.

Note that AMD64 is also known as "X86-64". Refer to "www.x86-64.org".

MS Windows edition in that case (i.e. CBS's article) was MS Windows XP AMD64 edition (beta) (a.k.a Windows Anvil). MS Windows XP AMD64 edition runs Win32(X86) applications i.e. mix modes.  

Reference;
CBS's Article

The Inquirer.net's Article

[Rodney]

I'm confused by this...isn't the pentium 4 a 32-bit processor??
Why is the AMD 64 competing in the 32-bit market?

(Been out of the CPU loop awhile)

Their competing in the desktop/workstation market, which happens to be 32bit. Do you want to stay at 32bit for ever? Someone has to come in and make a stand!

The only current 64bit chips are not for normal use, either workstation or servers. AMD are competing with intel, i dont see what it has to do with them being either 32bit or 64bit.

Please note, they also have other 64bit chips aimed at other things besides the desktop.

[GreggBz]

As I undersand it, the AMD-64 is basically an Athlon with 64 bit extensions pasted on. Much like a 386 was a 286 with 32 bit extensions pasted on.

I was a bit disapointed when I discoved it's nature.. I was rather hoping that AMD would design a 64 bit processor from the ground up for the masses. Unfortunately, three things prevented them from doing that.
Backwards Compatability
Backwards Compatability
and
Backwards Compatability

Looks like we will be in a windows PC world for a long time to come... I bet I can still run star control and where in the world is carmen sandiego on my new AMD-64 also.. argh.

[GreggBz]

Ohh man. come to think of it the 386 had thee modes as well. Can't the establish some new paradigmns?
Is everyone afraid to push the envelope and ignor all that's come before. Look at all the inovation we had in the 80's when Backwards Compatability was'nt an issue..

The 386's modes as best I remember..
Real Mode (8 bit 8088 emulation)
Protected Mode (16-32 bit 80286 emulation with  80386 adressing
Enhanced Mode (32 bit)

)

[bloodline]

GreggBz wrote:
As I undersand it, the AMD-64 is basically an Athlon with 64 bit extensions pasted on. Much like a 386 was a 286 with 32 bit extensions pasted on.

I was a bit disapointed when I discoved it's nature.. I was rather hoping that AMD would design a 64 bit processor from the ground up for the masses. Unfortunately, three things prevented them from doing that.
Backwards Compatability
Backwards Compatability
and
Backwards Compatability

Looks like we will be in a windows PC world for a long time to come... I bet I can still run star control and where in the world is carmen sandiego on my new AMD-64 also.. argh.

The "Long Mode" (64bit mode) has a new architecture. THe instruction set has been streamlined and the number of general purpose registers has been doubled (and thier size has been doubled too). I suggest you READ THIS to find out more.

The AMD64 is basicly a brand new CPU that is able to run x86-32 bit code with no speed penalty. The Itanic is also a brand new chip that is able to run x86-32 code, but incurs a massive speed penalty.

Imagine if the PPC had been designed by taking a 68k and then creating a "Coldfire type" mode and then extending that mode to have 32 General purpose regs etc.

[ksk]

Wain wrote:

I'm confused by this...isn't the pentium 4 a 32-bit processor??
Why is the AMD 64 competing in the 32-bit market?

The big money is in desktop CPU market.
Dekstop CPU market is where the mainstream SW is.
Mainstream SW is 32bit x86 SW.
AMD64 runs ALSO 32bit code damn fast.

64bit desktop market does not exist.