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
Half-Time Summary
At this point we’re done with talking about all of the microarchitectural changes that have gone into Prescott. We know it’s a lot of information so let’s go through a brief rundown of what we’ve learned so far:
- Prescott’s 31 stage pipeline by itself makes the processor significantly slower than Northwood on a clock for clock basis.
- Prescott’s L2 cache, albeit larger than Northwoods, has a higher access latency – also resulting in lower performance for the 90nm chip
- Through improvements in branch predicting, scheduling algorithms and integer execution, Intel has managed to hide a lot of the downsides to extending the pipeline.
- The large L2 cache also helps keep the pipeline full.
- SSE3 instructions will be useful down the road, but the impact given today’s software will be negligible.
- Extending the pipeline to 31 stages will allow Prescott to scale to speeds in the 4 – 5GHz range next year. It will take those speeds to make Prescott a true successor to Northwood.
With that said, let’s look at more of the common areas of discussion about the new chip.
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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.