Intel's Pentium 4 E: Prescott Arrives with Luggage
by Anand Lal Shimpi & Derek Wilson on February 1, 2004 3:06 PM EST- Posted in
- CPUs
The Pentium 4 has come a long way since its introduction in the Fall of 2000. It went from being a laughable performer, to a CPU embraced by the community. Today Intel is extending the Pentium 4 family with the third major revision of the chip – codenamed Prescott.
Back when Prescott was nothing more than a curious block on Intel’s roadmap, we assumed that history would repeat itself: Intel would move to a smaller, 90nm process, double the cache and increase clock speeds. Intel has always historically behaved this way, they did so with the Pentium III and its iterations, and they did so with the first revisions of the Pentium 4. What we got with Prescott was much more than we bargained for.
Intel did move to a 90nm process, but at the same time didn’t produce a vastly cooler chip. Intel did double the cache, but also increased access latencies – a side effect we did not have with Northwood. Intel also moved to Prescott in order to increase clock speeds, however none of those speeds are available at launch (we’re still no faster than Northwood at 3.2GHz) and Intel did so at the expense of lengthening the pipeline; the Prescott’s basic Integer pipeline is now 31 stages long, up from the already lengthy 20 stages of Northwood. With Prescott, many more changes were made under the hood, including new instructions, some technology borrowed from the Pentium M and a number of algorithmic changes that affect how the CPU works internally.
If you thought that Prescott was just going to be smaller, faster, better – well, you were wrong. But at the same time, if you view it as longer, slower, worse – you’re not exactly on target either. Intel has deposited a nice mixed bag of technology on our doorsteps today, and it’s going to take a lot to figure out which side is up.
Let’s get to it.
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Jeff7181 - Sunday, February 1, 2004 - link
I'm going to go out on a limb here and say 2004 is the year of the Athlon-64 and Intel will take a back seat this year unless their new socket will help increase clock speeds. When AMD makes the transition to 90nm I think you'll see a jump in clock speed from them too... and I'm willing to bet their current 130nm processors will scale to 2.6 or 2.8 Ghz if they want to put the effort into it before switching to 90nm.Intel better hope people adopt SSE3 in favor of AMD-64 otherwise they're going to lose the majority of the benchmark tests.
On second thought... the real question is how high will Prescott scale... will we really see 4.0 Ghz by the end of the year? Will performance scale as well as it does with the Athlon-64?
Right now, looking at the Prescott, the best I can say for it is "huh, 31 stages in the pipeline and they didn't lose too much performance, neat."
Barkuti - Sunday, February 1, 2004 - link
Check out the article at xbitlabs:http://www.xbitlabs.com/articles/cpu/display/presc...
Less technical but with a wider set of tests.
Stlr22 - Sunday, February 1, 2004 - link
;-)Stlr22 - Sunday, February 1, 2004 - link
((((((((((((((CRAMITPAL))))))))))))))))Listen,I just want you to know that everything will be alright. Really, life isn't all that bad buddy. It's not good to keep so much hate inside. It's very unhealthy. We are all family here at the Anandtech forums and we care about you. If you ever need to sit down and talk, I'm ll ears pal. So that your brother doesn't feel left out, here's a hug for him aswell.......
(((((((((((((AMDjihad)))))))))))))
KF - Sunday, February 1, 2004 - link
Yeah, the Inquirer was right about 30 stages. Maybe I should start reading it! However I did read the one where the news linked to an article purporting that an Inquirer reporter had bumped into a person who had overheard an Intel executive say Prescott was 64 bit. Maybe Derek and Anand didn't have the space to squeeze that tiny detail into the review.I saw a paper on the Intel site a while ago, seemingly intended for some professional jounal, the premise of which was that it is ALWAYS preferable to make the pipeline longer, no matter how long, while using techniques to reduce the penalties. Like, 100 stages would be a good thing. Right then I knew what one team at Intel was up to. The fact that they didn't explain any new penalty reduction techniques only made it all the more sure what Intel had in the works (otherwise why write the paper?), and that they had the techniques worked out, but still under wraps.
ianwhthse - Sunday, February 1, 2004 - link
Err.. *CramitpalSorry about that. My mind is wandering.
ianwhthse - Sunday, February 1, 2004 - link
Did we actually just get 26 good posts in before crumpet showed up?FiberOptik - Sunday, February 1, 2004 - link
I like the part about the new shift/rotate unit on the CPU. Does this mean that prescott will be noticeably faster for the RC5 project? Athlon's usually mop the floor with whatever the Northwood can pump out.eBauer - Sunday, February 1, 2004 - link
"Botmatch has bots (AI) playing, shooting, running, etc. (deathmatch) while Flyby does not. The number that you should be most interested in is the Botmatch scores."No, I am talking about the botmatch scores from previous articles. Well aware of the difference between flyby and botmatch. http://www.anandtech.com/cpu/showdoc.html?i=1946&a... In that article, all CPU's had about 10 more fps than the CPU's in the prescott article.
AnonymouseUser - Sunday, February 1, 2004 - link
"I am curious as to why the UT2k3 botmatch scores dropped on all CPU's... Different map?"Botmatch has bots (AI) playing, shooting, running, etc. (deathmatch) while Flyby does not. The number that you should be most interested in is the Botmatch scores.