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Linus on Intel's 64 bit Extensions
ceswiedler writes "KernelTrap is running a thread on the Linux-Kernel mailing list about Intel's new IA-32e 64-bit chip. Linus complains 'what I found so irritating is that _hours_ after the Intel announcement,
people were _still_ confused about whether the new intel chip was actually compatible with AMD's chips.' It is, of course, but you have to do a thorough comparison of Intel's reference manuals to discover that-- they don't mention the fact that their new chip is instruction-set compatible with AMD's x86-64 chip." See the previous story for background. So it looks like the reason Intel was vague about their announcement is that they didn't want the WORLD TO KNOW THAT THEY WERE COPYING AND FOLLOWING AMD rather than developing some new thing on their own. Slashdot is proud to help Intel in this quest; wouldn't want the public to know that INTEL WAS SIMPLY FOLLOWING IN AMD'S FOOTSTEPS. Hope this helps.
It's about bloddy time. Isn't that what's next?
"The absurd is clear reasoning recognizing its limits"
-Albert Camus
Intel had no choice but to use AMD's instructions if they wanted their chips to be Windows-compatible.
Intel doesn't have to be as careful as you may think. The general public has no idea about Intel/AMD differences. This makes it much easier on Intel to just keep producing crap that is just couple tenths of a gigahertz faster and pass it off for a few hundred more dollars and make more profit. AMD is still not close to taking the processor lead.
those people who think they know everything are a great annoyance to those of us who do. -isaac asimov
Uhm, didnt i read somewhere that Intel licensed AMDs 64bit extensions? Just the same as AMD license ia-386 stuff from Intel? This may be covered in the article, which I cant currently get to, and i just cant be bothered to google.
Given a general cpu register like eax it looks like this:
31--------------15-------7------0 Bits
|--------------eax--------------|
|------ax------|
|--ah---|--al---|
And now AMD's come up with the brillant idea of extending a register. The 64 bit accumlitive register is now RAX with it's low 32 bits being EAX and the low 16 are ax and so on.
The continuation of adding on register extensions is great for backwards compatiblity but it makes the instruction set a mess. Intel knows this but people don't seem to be will to give up compatibility or performace. The only way this is probably ever going to go away is if every one is forced to write a C compiler.
The sad thing is that a new cpu could have a compatibility layer that had a slight performance hit but with a lack of software supporting new 64 implementations people wouldn't buy it because the pretty little bar graphs that the sales drones produce.
My Hello World is 512 bytes. But it's also a valid Fat12 boot sector, Fat12 file reader, and Pmode routine.
Seriously people, everything but x86 is Big endian, and we (embedded software people) have endian issues all the time. Wil there finally be 32 and 64 bit big endian instructions?
PLEASE SAY YES!
Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
Downplaying the announcement wasn't just to keep down the shame of following their chief rival, it was also to confuse those in the current market for a new server. From what I understand, Itanium/Itanic has been a serious flop thus far. What will the motivation be for IT departments to buy Itaniums now if they know something more compatible and better for them is coming along Real Soon Now?
"they're adopting a technology developed by a company a fraction of their size with a fraction of the resources. It gives AMD much more credibility."
How much credibility is AMD really lacking when buck for buck they've almost always been a better deal for the speed than Intel? How much are they really lacking when they beat Intel to the 1 GHz mark and for a long while thereafter had the fastest x86 desktop chip on the market? Or when they beat Intel to wide market penetration with 64 bit chips? Or when they beat Intel to 64-bit on the desktop? Or when benchmarks showed that the Athlon FX-51 beat both Intel's flagship and PPC chips?
If AMD doesn't have credibility now, this 'specification war' won't give it to them if you ask me.
Cheers
~Dalcius
Rome wasn't burnt in a day.
http://www.pbs.org/cringely/pulpit/pulpit20021226. html
Either way, it only helps the consumer to have a standard like this.
Rambus was a different way of organizing memory. In some ways it was better in others worse. I liked the analogy of using a train (RAMBUS) or a fleet of trucks (SDRAM) to deliver data. The train works great when you have to move a ton of stuff from one place to another, the trucks work better when you have to move lots of little loads from many places. Video editing is an area where RDRAM shines, multitasking is a disadvantage. Now there were many things that served to help RDRAM in its disadvantages, the P4 was developed to work very well with RDRAM it loved the bandwidth and made up for the latency with clock cycles. Dual channel was a big part of the enhancement, too. Have you ever been stuck on a machine with only a single stick of RDRAM or a P3? DDR was much faster. Once you got over about 128 MB of RDRAM you ended up waiting a long time for the addressing scheme to access different portions of RAM. When you pulled from each area sequentially, it was wonderful. I'm typing this from an early P4 that used RDRAM and it works quite well, but I wish the company had waited for socket 478.
Price performance was an easy win for an Athlon with DDR in those days. I'd love to find the powersupply and finally put together a dual xeon with a whole boatload of RDRAM and some fast drives.
Degaussing scares the bad magnetism out of the monitor and fills it with good karma.
It is fairly well-known to insiders that Dave Cutler, chief software architect for Windows NT at Microsoft, approached AMD with the concept of extending the x86 instruction set for 64-bit instructions and data.
The motivation for this move was probably complicated, but Intel's slow-motion malaise regarding its IA64 strategy was no help. Microsoft needed a 64-bit platform that would gain wide acceptance before it devoted a significant amount of resources to drive Windows support on the platform to consumer-level quality.
Some even make the further claim that Cutler may have actually designed the instruction set for AMD and handed it to them intact. In other words, he approached them and said, "If you build a chip that runs this instruction set, we can guarantee NT support for it, and backwards compatibility with x86-32 will come for free."
AMD even acknowledges Dave Cutler and has a page with his information on their web site. If you do a search for articles, you'll find supposedly leaked memos mentioning builds of NT running on the new chip before it was even announced publicly (and hence before SuSe knew about it either).
You be the judge.