Lets start with the sledgehammer:
This belongs to AMD. Just like in the past the Intel 8088 morphed to the 8086 into the 80286 (16bit) then to the 80386 (32bit), 80486 (32bit with built in Floating point unit). Now onto the Pentium range, we haven't seen an "upgrade" in calculation precision or data sizes/types.
The Sledgehammer is the move from a 32bit to a 64bit whilst maintaining backward compatbility. Just like the 386 was a 32bit upgrade from a 286. The Sledgehammer is going to be a 64bit chip based on a 32bit chip (the Athlon). The Sledgehammer, due to maintaining all "x86" registers, will not require "recompiling" to get 32bit code to run on it. To take advantage of the 64bit portion of the chip, software (including the operating system) must be specially written/compiled).
The Itanium is the Intel beast that they have introduced into the 64bit world. The Sledgehammer is going to be pitched at a "medium" database server or high end multiprocessor application server. The Itanium is meant to be entering the realm of long time 64bit processors such as the Alpha (Compaq, API, and others) or the Ultra Sparc (Sun Microsystems). The Itanium is designed for multiprocessor systems from the ground up, and is optimised for 64bit code.
32bit code will suffer on the Itanium but 64bit code will excell. Naturally however, the 64bit code on a Sledgehammer will not be able to run on a Itanium.
I've cut this short because i'm short on time Thus a few facts are out of whack, but the general idea is there.
Wow! I had a hard time following that. I don't think Cltek is that computer savy by the question he was asking.
Let me try to translate parawolf.
Sledghammer is AMD's idea of the future of processors while the Itanium is Intel's. Both are 64bit processors.
16bit, 32bit, and 64bit refer to the instruction set the processor uses to run software programs. The instruction set is "hardwired" in the processor. Remember everything a computer does is binary (0's and 1's) and so everything we want to do (word processing, graphics, photos, games) has to be converted into binary. For example, take the number 123,456,789; this converts to 111010110111100110100010101 in binary. That is a 27 bit number. If you were using a 16bit instruction set, you would have to run whatever calcation twice to get your result (only 16bits at a time). With a 32bit instruction set you can do a calculation with this number in one run. With a 64bit instruction set, you can run a calculation with two numbers like this at the same time--assuming your doing the same calculation. Since most of the time you are doing the same calculation on a bunch of numbers, you have just doubled the number of calculations you can do per unit of time. This makes higher bit processors inherently faster but they are harder to make which is why they aren't already out yet.
Most software out there is optimized for 32bit processing, Windows excluded. Currently, no software is optimized for 64bit processing. The same problem existed when the first true 32bit processors (the 486)came out. At that time, Intel incorporated what it called real mode and virtual mode procecessing, ie, 16bit and 32bit processing in the chip itself to keep it backward compatable.
AMD plans to do something similar with the sledgehammer, a true 64bit processor, to keep it backward compatible with all the software out there.
Intel has decided not to do that. I guess it wants to push the software makers harder into going to 64bit code. What this means is, the Itanium will have to translate 32bit code into 64bits before it can process it which will greatly slow it down--slower than an 32bit processor running at the same speed.
Maybe I'm a whole lot more tech iliterate then I thaught...but it seems to me that 32 bit code should fly on a 64 bit system even without optimization. I don't know all the ins and outs of programming, but if it can calculate twice as fast and runs the same instruction sets...why wouldn't it behave twice as fast at a given clock speed?
November 27, 2000 10:55:54 AM
I may be wrong but I think the Itanium is a different Architecture completely , that's why it has problems with legacy code...
the itanium is a different architecture. For it to run a 32 bit application it has to use a 32 bit emulator which of course slows it down quite a bit. My understanding of it-and if I'm wrong someone please correct me- is that Itanium is not an x86 chip. This is why it needs the emulator and is not backward compatible with 32 bit programs. Sledgehammer will be basically a two processor chip, with a part of it designed to run 64bit aps. and another part deticated to 32 bit apps only.
jg38141 is exactly right.
Intel and HP got together and wrote an entirely new instruction set for the Itanium, abandoning the now aging x86 32bit instruction set. They then added in a emulator that will translate the instructions from 32bit to 64bit, which can be from 1 to a dozen steps depending upon the instruction. Therefore, though it will fly when carrying out 64bit instructions, it will flounder with the 32bit as it has to translate them first.
AMD will also use the new instruction set but will also keep the old instruction set in the chip. This makes the chip more complex and theoretically slower than the Itanium; but it won't have the same problem with handling 32bit instructions.
MMX, SSE, and SSE2 have been Intel's attempt to prolong the life of the x86 32bit instruction set.
The new Itanium instruction set is no longer even using a CISC (Complex Instruction Set Computing) archetecture like the x86 but is using what is called IA-64 which is a RISC (Reduced Instruction Set Computing) archetecture--which is what Motorola uses in the powerpc chips for the Mac.
So if you have ever seen a Mac emulating a pc you will have an idea of what I mean by floundering with 32bit instructions. At least that is what is expected. The chip is not expected to be released in quantity until most likely 2002 and then we will see just how smart or not, Intel is.
I read someone say "Slegehammer will not work with Itanium 64 bit code". AMD and Intel are both building their processors around Windows 2000's 64bit version. They will both be able to run 64 bit code. How they do is totally different.