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Intel Plans CPU Naming Change
Jemm writes "According to The Globe and Mail, Intel will start using performance numbers rather than clock speed to number their chips. 'Under the model number system, processors will be given numbers to describe their performance, in addition to being described as running at 2GHz or other speed.'"
The AMD numbering system has never been directly related to Intel's (officially) but is instead related to the performance of older Athlons... in effect saying "The XP 2700+ is roughly equal in speed to an original Athlon running at 2700 Mhz"
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Really, the technical community needs to sit down and figure out a universal cross-platform benchmarking method.
Well, there's SPEC and TPC. Other than that, benchmarks are both overrated and the best metric we have for evaluating performance. Then you have cases when a CPU is optimized for a particular benchmark to inflate performance numbers (hence the term benchmarketing).
Doesn't FUD imply it's untrue? If you don't like AMD (I don't, they just had a convenient explanation to link to), it's a similar situation with Apple, though they have a different architecture entirely.
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Actually its not the origional Athlon. Its the Tbird that they compare it to.
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Older intel CPUs used a performance metric named iCOMP which was stamped on many CPUs. A bit of googling suggests this is still around. Perhaps this is another case of reinventing an old idea?
Intel has NEVER stated that Mhz equals performance. Go look on their site. They like to quote SPEC, and their own performance tests, and all the rest of the BS that companies do. Never Mhz. The Mhz myth comes from two places:
1) Fanboys. I first remember it gaining real popularity among the Apple fanboys when Apple went PPC. They claimed that the PPC showed a positive second derivitave (growth of growth) in Mhz where Intel showed a negative second deravitive and how PPC could scale to huge speeds that CISC just couldn't handle. That of course, neve came to pass. Which lead us to:
2) The anti-Mhz myth. That Mhz don't mean anything. This is just FALSE. When you compare a single architecture (meaning one kind of one brand of processor) mhz give a VERY good idea of how performance will scale. If something gets X on a processor at 500mhz, you can with confidence say it will get nearly 2*X with the same kind of processor at 1000mhz. That doesn't mean it's the be-all, end-all benchmark, just a useful (and truthful) was of evaluating chip performance within a line.
PR numbers are just a bunch of crap. So far, I've never even seen any that are reliably based off of benchmarks. Even if they were, it wouldn't matter. Show me any benchmark, I'll show you how it's not relivant to things a lot of people do. Like take SPEC. It is a big industry standard benchmark. People doing scientific and engineering work place a lot of faith into it since it benchmarks what they do.
Well Intel LOVES SPEC, their processors when mated with their compiler do very well at it. Does that mean we should use it? Hell no. SPEC isn't applicable to everyone. It's got nothing to do with games, audio, video, bussiness, servers, etc. It's a science and engineering benchmark. What's more, it's a benchmark designed to come form source code, so to bench the compiler as well as the system. It's a good, open, standard benchmark, but it won't work as the single number to completely describe chip performance (nothing will).
PR numbers improve nothing, and just confuse and BSify the situation. At least Mhz are factual numbers and have some basis in reality. From what I've seen of PR numbers, they are mainly a dream of marketing and don't apply to the real world.
Uninformed consumer goes to the local discount electronics store. Looks at a computer based on Intel's CPU, sees 2000 megalobangerz. Looks at the AMD based computer right next to it, sees 1800 megalobangerz for a hundred bucks less. Decides the Intel is "better", so its ok to cost more. Reality, the computers are pretty much the same.
AMD did this becuase their chips simply do more work per clock cycle, this was done at the expense of not being able to scale the clock nearly as high as Intel. A 2000+ AMD is *roughly equivillent* to a 2.0Ghz P4.. it wins some, it looses some.
The jump you talk of was at 2600+, when AMD went from a 2.0 Ghz at 266 mhz FSB (called a 2400+) to a 1.833 Ghz at 333 mhz FSB, called a 2600+ Barton. Performance #s goes up, clockspeed goes down.. but FSB goes up! Yes, it's annoying, but this was done as to give most consumers who do minimal research a "fairer" basis for comparison when shopping for computers.
MHz is an absolutely useless metric for comparing processors today when FSBs range from 200 mhz to 800mhz and cache from 128kb to 1MB and higher. Intel and AMD went different routes when designing their offerings, and as you say, it's very difficult to come up with a single number to describe their performance. The problem is that MHz is the number that has been 'historically' used, and it just so happens that AMD went the route that yielded a smaller MHz (and god bless them that they did); so they made the transition to a BS-marketing-numbers system.
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and please mod this person up. (S)He is correct in stating that the AMD model numbers are derived NOT from the Pentium 4, the Athlon classic, the Centrino, Celeron, PIII, Crusoe, 8088, or any other God-forsaken chip, but from the Thunderbird core Athlon CPUs. Those were the last Athlons to advertise the clock frequency, and thus were the obvious choice for a comparison chip for the next generation of processors. If I just bought a 1.4GHz Thunderbird Athlon (common chip for the time), I would expect that an AthlonXP 1500+ would perform better than it, and I would be correct. An AthlonXP 1500+ under the new rating system, were it to be compared to the Athlon classic core (far less efficient than Thunderbird) would probably run at about 1.1GHz. As it is, the AthlonXP Palomino core 1500+, being a relatively minor revision to Thunderbird, ran at 1.33GHz.
So mod this guy up. He's right, the post he's replying to is wrong.
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Because the baseline isn't an Intel chip? The baseline for AMD's pro-rating scale is a 1GHz Duron. IE: A 3200+ is 3.2 times faster than a 1GHz Duron.
Doesn't FUD imply it's untrue? No. FUD is fear, uncertainty, and doubt. It's what results when a fact is unknown, yet decisions have to be made based on that fact. If we knew that the FUD-source was false, it wouldn't produce any FUD. Unfortunately, we can't be so sure.
How about an explanation of the numbering system right from the horse's mouth
mirror
from AMD's athlonXP site (doesnt' seem to be working right now)
web archive of AMD's site
My server
Now that's a trend I think is broadly continuing. Multi core CPU's are a part of it. We may also see async processors coming out with zillions of transistors, but no central clock.
That's nothing, the adc and sbb (add and subtract with carry) instructions take 8 cycles! That is 8 times what it was like on the Pentium 3. At least the add, sub, xor, not, and, or, neg instructions take only 0.5 cycles.
Not Duron, but older Athlon Thunderbird. And it does not mean "3.2 times faster than Duron", it means it is fast as 3200MHz TBird would be.
http://en.wikipedia.org/wiki/PR_rating
Why does this incorrect info keep getting posted (and modded as "informative" at that)? AMD stated several times quite publicly that their rating initially was meant to compare against the "Thunderbird" Athlon chips. More recently they've simply said that it's relative performance between the AthlonXP line and that it can "outperform it's closest competitors". Here's a direct quote from AMD's AthlonXP FAQ
Q: What does the 3200+ model mean?
A: This is a model number. AMD identifies the AMD Athlon XP processor using model numbers, as opposed to megahertz. Model numbers are designed to communicate the relative application performance among the various AMD Athlon XP processors. As additional evidence that performance is not based on megahertz alone: the AMD Athlon XP processor 3200+ operates at a frequency of 2.2GHz yet can outperform an Intel Pentium(R) 4 processor operating at 3.0GHz with an 800 FSB and HyperThreading on a broad array of real-world applications for office productivity, digital media and 3-D gaming.
AMD's model numbers not rated against Intel's P4 chips? You might want to tell AMD that!
Gigaflops is only a tiny fraction more useful than GHz, if at all.
Gigaflop tests come in three basic varieties. First are ones that fit entirely into the L1 cache of a processor, making the memory subsystem totally irrelevant. This is no good since the memory subsystem plays an important role in performance. In this sort of test a 2.8GHz Celeron processor with 128K of L2 cache and a 400MT/s bus speed would get a score essentially identical to a 2.8GHz P4 with 512KB or 1MB of L2 cache and an 800MT/s bus speed. In 90% of real-world applications though even a much slower 2.0GHz P4 would beat the pants off a 2.8GHz Celeron (the current Celeron chips are absolutely abysmal perfomers).
The second type of gigaflops test has a slightly larger dataset, so performance is almost entirely determined by what level of cache it fits into. For example, if they used something like a 60K dataset, an AthlonXP or Athlon64 would blow the doors off any P4 because it would be running everything in L1 cache while the P4 would be running out of (the much slower) L2 cache. Clock for clock the AthlonXP chips could easily be twice as fast in such a test. Things would get even worse if your data set fit into the L2 cache of one chip but not another, ie if you had a 750K data set, a "Prescott" P4, with 1MB of L2 cache, could be HUGELY faster than a "Northwood" P4 with only 512KB of L2 cache, even though in reality their performance is fairly close (with the "Northwood" usually being slightly faster).
The third option would be to use a HUGE dataset, turning this entirely into memory bandwidth test. Fine for what it's testing, but hardly an accurate picture of overall performance.
There are good reasons why the rather smart guys over at Ace's Hardware make use of Linpack (basic Gigaflops test used by Top500.org) to show off the memory subsystem of platform. By varying the size of your dataset it does a good job of illustrated the effects of cache and memory. However it doesn't tell you much else about processor performance.
I think that gigaflops would be a slightly worse metric for processor performance than MHz because it's FAR easier to abuse that test. The best thing for consumers is if the model numbers are really NOT meaningful at all. For example, look at video cards, where our top-dogs today are the ATI Radeon 9800 and the nVidia GeForce 5900. Nobody looks at those and says "Ohh, 9800 is bigger than 5900, therefore the ATI MUST be better". Everyone KNOWS that the model numbers here are meaningless, so if they want to know which is faster they ask a friend (or at least the salesperson) or do some research on their own. That is what I would like to see for processors as well. AMD's already got this with their Athlon64 FX line and Opteron line of processors. Hopefully Intel will do the same.