. . . or Do They?

However, further tests with the 3.6 Engineering Sample shed more light on the question.

Asus P5AD2 (Intel 925X) - Highest Stable Overclock - 3.6 ES
CPU Multiplier Voltage Highest FSB CPU Speed % Overclock
3.6 ES 14 Default 992 (248) 3472 24%
3.6 ES 15 Default 992 (248) 3720 24%
3.6 ES 16 Default 992 (248) 3968 24%
3.6 ES 17 1.425V 952 (238) 4046 19%
3.6 ES 18 1.425V 896 (224) 4032 12%

While the 3.6 ES was also able to reach around 4GHz when overclocked, this represents only a 12% overclock for this chip. It is not unusual for top-of-the-line processors to achieve a more modest overclock percentage than lower clocked CPUs that probably are off the same line. The advantage here is that the ES chip allows the setting of lower multipliers to determine the maximum overclock potential of this motherboard.

We should be able to achieve the same approximate 4GHz at lower multipliers - but with higher FSB. At a 14 multiplier, 288x14 would give us about the same CPU speed as 18x224. However, we find that the highest FSB that we can achieve is the same 248 maximum we found on the 3.2GHz. In fact, whatever the multiplier, 248 was the highest FSB setting that we could achieve.

While we can't be certain whether 248 is the limit of the Asus P5AD2 motherboard or an artificial limit of the chipset, we suspect that we are dealing with chipset limitations. It appears that Asus has effectively bypassed the Intel Overclock Lock, but the design of the lock cannot be completely bypassed. Even a clever design like the Asus still seems to be overclocking limited to around 25% above rated speed.

Asus Breaks the Lock . . . Our Take
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  • artifex - Saturday, June 26, 2004 - link

    Did you read about Intel's new recall of 915 and p25 chips? Please look into whether boards shipping afterwards might be modified in such a way as to affect the performace you're reporting...
  • Xentropy - Friday, June 25, 2004 - link

    I find it kind of amusing how people react to something they had predetermined to love vs. predetermined to hate. It's not like AMD hasn't enacted limitations on overclocking as well. They continued to use more and more difficult to defeat multiplier locks on the Athlons (the whole tape and superglue thing, for instance). But the reactions of many heavily biased members of Anandtech have been approximately as follows:

    (AMD implements overclocking limitations.)
    Anandtech Readers: Oooh, cool!! A new puzzle to solve and get around the limits!

    (Intel implements overclocking limitations. Asus and most other enthusiest board mankers unlock the puzzle in under a week.)
    Anandtech Readers: NO FAIR! INTEL SUCKS!

    I mean, come on people. Are people really so blind to double standards these days? Or are you just mad that the mobo makers are doing the unlocking for you instead of whole threads forming on forums all over the net to figure out which capacitors to bridge or lines to cut?
  • AtaStrumf - Friday, June 25, 2004 - link

    Early silicon = problems

    I egree that 248 MHz could very well be chipset's limit right now.

    I'm glad that AMD isn't making their own chipsets or else this is exactly what we would be seing in their next chipset.

    BTW, according to overclockers.com's pool the major reason many enhusiasts buy Intel is their chipset, so this OC lock/limit is a definately a big thing. On the other hand Intel probably doesn't care much for overclockers anyway, so loosing some or even most of them to AMD isn't that big a deal for them. I'm sure they have bigger problems to worry about.
  • Pumpkinierre - Thursday, June 24, 2004 - link

    Wesley #27, you did'nt mention the ABIT 9xx boards in your article. Are they getting the same 248MHz limit? It just seems strange that if they have overcome the Intel 10% o'clock limit why they would hit another one at 24%. Given Trog's #26 comparison to earlier A64 boards could it be due to failure of the AGP/PCI/PCI-E lock/dividor?

  • TrogdorJW - Thursday, June 24, 2004 - link

    #27 - Wesley:

    Yeah, I understand that the 10% overclock limit is real. It sucks, but it's not a deal-killer to me since I generally only boot my system once a day. (Not that I'm really looking to buy any P4 system right now anyway....) Hopefully it doesn't get worse, or on the other hand this might give alternative P4 chipsets (i.e. Via, SiS, etc.) a better chance. I'm just wondering if the 248 MHz overclock with the "fixed" boards is still limited, or if that's due to the early nature of the chipset, boards, etc.

    So, forget all that: how about getting an Abit AS8 and getting us some results from that? I can live without PCIe for the time being. Sure, Athlon 64 is going to be cheaper and faster, but I am very curious to see what sort of overclocking results can be achieved with 875P + Socket T. :)
  • araczynski - Thursday, June 24, 2004 - link

    i'll reiterate, WE as enthusiasts are on the bottom of Intel's 'care about' chain, they don't start any design with US in mind, everything is about the Dell's/Gateways/Systemax/Sony/etc., they don't even give a rat's ass about the small potatoes of Alienware/Voodoos/etc.

    and quite frankly, whether i choose to buy an intel or amd for my own personal computer at home, guess what i'll be (continuing) to buy for everyone at work....Dells with intels. who do you think wins in the end? What do you think intel's gonna care about in the end?
  • rjm55 - Thursday, June 24, 2004 - link

    The ONLY advantage Intel had left was that their Pentium 4 and Prescott chips overclocked very well. Since they have removed overclocking as an option with the 925X & 915 they have also removed my last reason to buy Intel.
  • Fr0zeN2 - Thursday, June 24, 2004 - link

    #25 - Yeah. I'll admit P4's OC very well, and certainly better than Clawhammer C0 steppings, but the point of this article is to highlight Intel strongarm tactics. I, for one, hate having my options artificially limited on some wanker's whim. Who knows if AMD would have done the same if they had majority market share, but for now it's Intel in the lead and as such they deserve fanboi bashing for doing things like this!! =)
  • Anemone - Thursday, June 24, 2004 - link

    So basically Intel doesn't give a hoot.

    I'll repeat - it's just time to buy AMD then. MS backs the AMD as a "great chip", and in effect forced Intel to be compatible with that instruction set.

    Now it's just time for the consumers to tell Intel what they really think "support us, because we're the ones paying for your products or 'goodbye'"

    It's really not all that hard to just you, and everyone you can possibly talk to, just buy AMD instead and watch what happens on the market. See what Intel fails to realize that the the ones who overclock talk to a LOT of folks about hardware recommendations. For me it is only in the thousands but I know its more for others.

    A shift of marketshare is the only real way to make Intel do anything. Now just go talk to people... :)
  • Wesley Fink - Thursday, June 24, 2004 - link

    #25 & #26 -
    There is definitely a 10% Overclock Lock on the new Intel 925X and 915 chipsets. It is not a matter of early chipsets, as the Overclocking has been intentionally limited to 10% by the Intel design. The point of the article is that a few of the majors have found ways partially around the Intel 10% lock, but the smaller players have not and are stuck with the 10% limit.

    It appears the majors, like Asus and Abit, have gotten around the lock by delaying the FSB set until after the boot sequence passses the settings as OK. We did notice the boot times on the Asus and Abit were very long when they were overclocked. The computer seems to sit at idle a very long time before a boot screen finally appears.

    All of these are bandaids for the 10% lock. The 10% limit is real and a part of 925X/915. That may or may not be important to you.

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