Prescott's Little Secret

In learning about Prescott and trying to understand just why Intel did what they did, we came to realization: not only is Prescott designed to be ramped in speed, but there was something else hiding under the surface.

When overclocking a processor, we can expect a kind of linear trend in performance. As Northwood's speed increases, its performance increases. The same is true for Prescott , but what is important to look at is increase in performance compared to increase in clock speed.

Prescott 's enhancements actually give it a steeper increase in performance per increase in clock. Not only can Prescott be clocked higher than Northwood, but as its clock speed is increased, it will start to outperform similarly clocked Northwood CPUs.

We can even see this trend apparent in our limited 3 clock speed tests. Most of the time, the 2.8GHz Northwood outperforms the 2.8GHz Prescott, but the percentage by which Prescott is outperformed decreases as clock speed increases, meaning that the performance delta is significantly less at 3.2GHz.

Business Winstone 2004

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
1.48%
3.00GHz
0.00%
3.20GHz
0.46%

Content Creation Winstone 2004

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-3.57%
3.00GHz
-5.67%
3.20GHz
-5.43%

SYSMark 2004

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
1.19%
3.00GHz
2.27%
3.20GHz
2.70%

SYSMark was one of the only applications to show a positive performance improvement for Prescott, and we see that with clock speed that advantage continues to grow over Northwood. Keep on reading, it gets even more interesting...

Aquamark - CPU Score

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-2.87%
3.00GHz
-2.47%
3.20GHz
-0.84%

Halo

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-0.18%
3.00GHz
-0.18%
3.20GHz
0.00%

GunMetal

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-0.29%
3.00GHz
-0.58%
3.20GHz
-0.29%

UT2003 - Flyby

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-2.62%
3.00GHz
-1.46%
3.20GHz
-0.86%

Clock speed goes up, Prescott performs more like Northwood.

UT2003 - Botmatch

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-3.55%
3.00GHz
-3.09%
3.20GHz
-2.05%

Warcraft 3

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
1.96%
3.00GHz
1.12%
3.20GHz
0.72%

We continue to see that as clock speed increases, the gap between Prescott and Northwood decreases as well.

Quake III Arena

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-1.33%
3.00GHz
-0.49%
3.20GHz
1.28%

Quake becomes the textbook case of what should happen to Prescott performance as clock speed increases; although initially it is slightly slower than Northwood at 2.80GHz, by the time we reach 3.2GHz Prescott holds an advantage over a 3.2GHz Northwood. This is exactly the trend we expect to see over time, especially once we get close to 4GHz.

Jedi Knight: Jedi Academy

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-7.63%
3.00GHz
-6.85%
3.20GHz
-7.04%

Wolfeinstein: Enemy Territory

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-5.53%
3.00GHz
-4.94%
3.20GHz
-3.79%

DivX Encoding

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-1.30%
3.00GHz
-0.61%
3.20GHz
-0.38%

3dsmax R5

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-9%
3.00GHz

-9%

3.20GHz
-9%

There will be some scenarios that do not work in Prescott's favor, and in those cases Northwood will still remain faster.

Lightwave 7.5

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-7.7%
3.00GHz

-7.3%

3.20GHz
-6.8%

Although to a much lesser degree, we are seeing the same sort of scaling with clock speed in applications like Lightwave. It looks like our theory about Prescott's performance is correct.

Visual Studio Compile Test

  Percentage Increase in Performance from Northwood to Prescott
2.80GHz
-8.2%
3.00GHz

-5.7%

3.20GHz
-3.8%

Much like Quake, our compile test is another perfect example of what clock scaling will do to the Northwood/Prescott gap. As the clock speed goes up, the performance delta decreases.

Development Workstation Performance Final Words
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  • mattsaccount - Sunday, February 1, 2004 - link

    From the HardOCP review: "Certainly moving to watercooling helped us out a great deal. In fact it is hard for us to recommend buying a Prescott and cooling it any other way."
  • eBauer - Sunday, February 1, 2004 - link

    I am curious as to why the UT2k3 botmatch scores dropped on all CPU's... Different map?
  • Pumpkinierre - Sunday, February 1, 2004 - link

    Sorry errata on #20 that was 3.0 Northood result is out of kilter with other cpus in dtata analysis sysmark 2004.
  • Pumpkinierre - Sunday, February 1, 2004 - link

    JFK,Vietnam,Nixon,Monica,Bush/Gore,Iraq and now this! - what is going on with the leader of the free world.I hope it overclocks well- that's all that's going for it. Maybe Intel should rethink their multiplier locked policy. AMD must get in there and profit. I still dont understand why the caches are running at half the latency as Northood if they are the same speed and structure? Is it as a result of a doubling in size for the same associativity?

    Good article- needs re-rereading after digestion. Last chart in Sysmark2004 (data analysis) has 3.0 Prescott totally outperformed by 2.8 Prescott and all other cpus. Look like a benchmark/typing glitch.
  • yak8998 - Sunday, February 1, 2004 - link

    first the error:
    pg 9 -
    The LDDQU instruction is one Intel is particularly proud of as it helps accelerate video encoding and it is implemented in the DivX 5.1.1 codec. More information on how it is used can be found in Intel’s developer documentation here.

    No link?

    ===
    "What's the power consumption like on these new bad boys?

    Is anything less than a quality 450watt PSU gonna be generally *NOT* recommended?? "

    I'm going to guess a clean running ~350W or so should suffice for a regular system, but I'm not positive with these monster gfx cards out rite now...

    "Any of you know what the cache size on the EE's will be?"

    If your talking about the Northwood (the p4c's are still considered northwoods, no?), its 1mb I believe.
    (still finishing the article. man i love these in-depth technical articles)
  • Tiorapatea - Sunday, February 1, 2004 - link

    I agree, some info on power consumption please.

    Thanks for the article, by the way.

    I guess we'll have to wait and see how Prescott ramps in speed versus 90nm A64.
  • AgaBooga - Sunday, February 1, 2004 - link

    Much better than the P4's origional launch...

    All I want to know now is what AMD is going to do soon... They'll probably counteract Prescott with high clock speeds but when and by how much is what matters.

    Any of you know what the cache size on the EE's will be?

    Also, the final CPU's based on Northwood are kind of like a car with the ratio curves or whatever they're called, but basically after a point of revving, going any higher doesn't give you as much of an increase in speed as it would at a lower rpm increasing the same amount.
  • Cygni - Sunday, February 1, 2004 - link

    AMD's roadmap shows a 4000+ Athlon64 by the end of the year... which is the same as Intel's. They are aware, im sure.
  • Stlr22 - Sunday, February 1, 2004 - link

    What's the power consumption like on these new bad boys?

    Is anything less than a quality 450watt PSU gonna be generally *NOT* recommended??
  • HammerFan - Sunday, February 1, 2004 - link

    Things are gonna get hairy in '04 and '05!!! My take is that AMD nees to get their marketing up-to-spec or the high-clocked prescotts are gonna run the show.

    I have a question for Derek and Anand: What kind of temps does the prescott run at? what type of cooler does it have? (there's nothing there to support or refute claims that the prescott is one hot potato)

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