Intel's Answer to AMD's Hammer - Yamhill

bdolan writes: "Today's San Jose Mercury News is reporting that Intel is going to put a 64 bit architecture extension in upcoming Pentiums if it turns out the Itanium doesn't take off. Hmm. Apparently they intend to only turn this on if AMD's 64 bit processor make major inroads against the Itanium architecture. Aren't we glad that competition is keeping everyone on their toes."

Comments

Re:The free market at work

[Pyromage]

It seems your trying to draw a parallel here to the MS case. That is not entirely possible in this instance.

There is one critical difference: it's possible to clone an x86 processor. They are standard and well documented.

You can't clone Windows. It is only partially open, with closed file formats and APIs all over the place. Open APIs are often not documented well, or may have undocumented bugs which applications depend on.

It is possible to make a chip that will run all the same applications as Intel's, and to do so in a reasonable timeframe. However, Wine and LindowsOS are clear counterpoints to that, showing that that CANNOT be done with an OS.

Yamhill

[sben]

For those who care, Yamhill is a small town WSW of Portland (the little red star at the lower left).

Fascinating info can be found at cityofyamhill.com, naturally.

Re:Uhh..naming?

[djoham]

There actually is a basis for this name. Intel has a large presence in the state of Oregon and has a tendency to give their products code names from that state.

For example, there's the Willamette (a major river, incidentally one of only a handful in the world that run south to north), the Klamath (a county) and the Deschutes (another county and also a national forrest).

There may be others, but they don't come to mind at the moment.

As a former Oregonian, I find this kind of cool...

Best regards,

David

Not exactly

[autopr0n]

The diffrence between the pentium and the p-pro are rather minute when compared with the diffrence betwee any pentium/486/386/etc chip and the Itanium. To really answer your question, though you kind of have to look at the history of the whole thing.

To start things off, intel releases the 8086, and the cheaper 8088 (8086 with a 8, rather then 16 bit bus interface). And thus begins the x86 era.

A little later intel decides they need a 32 bit CPU, but rather then design a totaly new chip, they just add a bunch of extensions to the 16 bit one. They call this new chip the 386, and it's supposed to revolutionize everything. The chip is totaly backwards compatable with the old 8086's and 286s (so the old register AX becomes EAX, but you can still access the first half as AX).

for a long time (windows 3.1) most software still ran in 16 bit mode, not really utilizing the software. IIRC It wasn't untill windows95 and NT started getting used that people really started to take the full potential of their machines in every day tasks.

Now, this is also around the time of the Pentium and the Pentium pro. The pentium ran both 32 and 16 bit software quickly, but the ppro ran 32 bit software faster, and 16 bit software more slowly (of course, the p-pro core became the pentium II, then the pentium III and ran at much higher clockspeeds, so it eventualy became a non issue, a 1.3ghz pIII is going to crunch 16 code faster then a pentium233mmx no mater what :P)

Now, when you look at what AMD is doing and I guess intel now with their rather odly named Yamhill is taking the orgional design and adding 64bit extensions the way they added 32 bit extensions to the 286. EAX becomes RAX, and you can get at the first half by calling it EAX and the first quarter by calling AX, etc.

Itanium is a totaly diffrent thing, it's a whole new system with x86 support tacked on extra, rather then tacking on 64 bit support to an aging archetecture.

Hrm, I hope that explains things.

Re:Not exactly

[tempmpi]

You are right: the p-pro core became the pentium II.
But the PII doesn't suck at 16-bit code because Intel done some little changes in the p-core so that the PII could crunch 16-bit code much faster. In fact there was only one problem with p-pro core design that caused the p-pro to suck at 16-bit code. The p-pro misses the segment register caches, that were included in the pentium and reincluded in the pII. Because of that 16-Bit programms that use segments will generate one additional memory access for every memory access they were doing. When Intel saw that that there was a need to run 16-bit programms they reincluded this caches and because that the performance of the pII doesn't suffer anymore from 16bit code.

There is also something important to note on AMDs x86-64 extensions. On the integer side they are really compareable to the 32-Bit extensions made in the 386 but the x86-64 extensions also change the working of the floating point unit.

All current x86 CPUs could reach very good benchmark scores on benchmarks that work mostly with integer numbers but they get bad scores at many benchmarks that use floating point numbers a lot. Intel and AMD are already trying hard to make their FPUs faster, but they couldn't reach really good improvements because the x86 fpu intestruction set isn't good for modern cpus. The x86 fpu doesn't have a normal register set with registers that could be addressed individually but it uses an register stack. You could only address the top of the stack(TOS), the register under the TOS,TOS-2 and so on. If you used a RPN calculator, you know what i'm talking about. This design isn't that bad if you execute one instruction at a time. It even makes programming fpu asm a bit easier.

The problems came with the introduction of cpu that executes more than one instruction at a time. To make full use of that feature the compiler or assembler programmer must often interleave multiple calculations. The fpu stack is very hostile against such optimizitions.

Because of that AMD has done a almost complete rework of the x86 fpu instruction set that matches the internal working of moderne fpus much more.

Re:"8086 took 3 weeks to design"-easy to believe!

[Detritus]

I think it is very unlikely that the 8086 was designed in three weeks. I used to have a book on the 8086, written by the chip's architects.For what the chip was designed to do, they did a good job. Intel thought that most of the software for the chip would be written in PL/M or Pascal. The segmented architecture was a good match to those languages. The floating point hardware (8087) was a major advance, being the predecessor of IEEE floating point. 8080 programs could be mechanically translated into 8086 programs. The 8086 supported all of the peripheral chips that had been designed for the 8080.