The introduction of Core 2 Duo about a month ago delivered a new processor with about a 25% improvement in performance over the fastest chips in the market. The top-line X6800, running at 2.93GHz, was the most flexible of the new processors, with completely unlocked multipliers up and down. This allowed settings like running at a 13x multiplier (stock is 11x) at 277 FSB (3.6GHz) at default voltage - the result of the incredible head room exhibited by the new Conroe processors.

Intel Core 2 Processors
CPU Clock Speed L2 Cache Price
Intel Core 2 Extreme X6800 2.93GHz 4MB $999
Intel Core 2 Duo E6700 2.66GHz 4MB $530
Intel Core 2 Duo E6600 2.40GHz 4MB $316
Intel Core 2 Duo E6400 2.13GHz 2MB $224
Intel Core 2 Duo E6300 1.86GHz 2MB $183

Unfortunately, the X6800 costs $999 which is way out of the budget range for many buyers - and it's even more at retail right now due to demand and availability, with the best price we're currently tracking at $1150. The good news is the lowest-priced E6300 outperformed every previous Intel chip. Compared to AMD the E6600 outperformed every AMD processor, and costs $364 to $433 compared to the $825 to $950 for the AMD top-line FX-62. (Almost all of the Core 2 processors are being marked up 10% to 20% at retail, though we expect prices to drop over the coming months.)

So is there a catch? The answer is yes and no. The X6800, as stated, is unlocked up and down, allowing the flexibility to do anything you wish with the outstanding head room of the Core 2 Duo architecture. The rest of the Core 2 Duo chips are hard-locked up and down, which greatly limits the flexibility of the head room which often runs 1000MHz, 1500 MHz, or more - depending on the CPU and motherboard. You could only access this extra power at the stock multiplier. This is actually a big negative compared to AM2 processors, where all chips are at least unlocked down.

ASUS has a history of incredible creativity in their mainstream motherboards. Those who recall the P865 Springdale will remember ASUS was the first to implement the "875 only" PAT speedup on the mainstream 865 - making the 865 just as fast as the more expensive 875. On the 925, where Intel had implemented a clock lock, ASUS was the first to find a way to break the clock lock and unleash extended speeds on their 875 motherboards. With this history in mind, it should not come as a surprise that ASUS has just introduced some very creative thinking in a new BIOS for their 965P chipset P5B Deluxe motherboard.

The new 0507 BIOS for the P5B Deluxe, dated 8/10/2006, has two new and exciting features:
  1. Provide better maximum overclocking.
  2. Add the ability to adjust the multiplier of most Conroe CPUs even if they are not Extreme Edition.
The P5B reached about 362x10 in testing for the Conroe Buying Guide: Feeding the Monster. This provides a baseline for comparing the new BIOS to previous results.

Even more exciting is that ASUS says they have found a way to unlock up or down most Conroe chips. This will be a significant new feature that is highly desired by many Core 2 Duo buyers. It didn't take but a few minutes for us to get the new BIOS flashed and a Core 2 Duo chip mounted to check this out.

A pattern has been developing for some time in test results from Core 2 Duo chips. The 2MB Cache chips, the E6300 and E6400, are generally overclocking a bit better than the 4MB E6600, E6700, and X6800 chips. Since performance of the 2MB is a bit lower than the 4MB cache at the same frequency, this means you can make up for some of the 2MB cache deficiency with the ability to run at a faster speed. With this in mind, testing was performed with all 4 of the Core 2 Duo chips that are multiplier locked - the 4MB E6700 and E6600, and the 2MB E6400 and E6300.

E6700 & E6600 – 4MB Cache


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  • mongo lloyd - Friday, August 25, 2006 - link

    Thanks, it's good to know that you'll consider such an article. The buyer guide article was good for the time yes. My reasoning is that it kind of defeats the purpose to buy the cheapest Core 2 Duo when you have to buy the most expensive memory to fully utilize it. Makes sense, I hope. Reply
  • Wesley Fink - Thursday, August 24, 2006 - link

    I suppose I could be glib and comment that Asus and Gigabyte will soon be the same company so our original reporting is correct. But I won't do that :) Several weeks ago it was announced that the two companies would merge, but brand identities will likely remain distinct - at least for a while.

    Gary and I did have a discussion about the Gigabyte board this afternoon, but there was a misunderstading between us about the unlock feature on the Gigabyte. Gary has explained this in detail in comments above, and he revised the article to reflect that the Gigabyte board also unlocks down, since not mentioning the Gigabyte was clearly an unintentional error that is now corrected. That will teach Gary to set me up :) Actually, Gary and I have been friends for years - long before I was with AT or Gary came on board with us. Gary is incredibly conscientious, and we are fortunate to have him on staff.

    I just got off the phone with Asus Engineering (it's Friday morning in Taiwan) who will provide more information on the chips they claim work on the up unlock and more information on how it works. ALL of the chips we tested unlocked down. None of the chips at AT - "Cherry-Picked", retail, E6700, E6600, E6400, E6300 would unlock and clock up - as we reported CLEARLY. We will update the article with the additional info from Asus when we get it.

    As for nothing new, I certainly consider the overclcoks we got pretty exciting. Gary owns the highest overclocks at 525 and 532 on several Forums since he unlocked the P5B. It is now clear the Gigabyte has the unlock down feature also, but I know for a fact the record overclocks didn't happen on the Gigabyte.
  • xsilver - Thursday, August 24, 2006 - link

    asus and gigabyte merge?
    this is news to me.. link?

    this would cause some serious monopolization of the market, which cant be a good thing?
  • Wesley Fink - Thursday, August 24, 2006 - link

    The news is on the Gigabyte website at"> You find the Asus news on the Asus site at">

    The "merger" was announced a few weeks ago in the Taiwan technical trade press.
  • xsilver - Friday, August 25, 2006 - link

    oh, not exactly a "merger"
    more like a partnership
    they will be producing a new set of boards together ala asrock type boards?
    any news if this partnership will be producing budget boards or enthusiast type boards, the press release doesnt mention that.

    has a name been decided yet?
    giga-sus ? lol
    as-byte? double lol

    I suspect this will be more a asrock type venture, where cheap mass produced boards can be made without affecting the parent brand name if questions of quality arise
    the benefits though as with asrock, have been the company being able to be more adventurous on designs and configurations?
  • JaredExtreme - Thursday, August 24, 2006 - link

    When I first saw the title of this article I was extremely excited.I was thinking to myself: "Asus adds unlocking? Awesome! I'll finally be able unlock those multipliers upwards on some cheap Conroes!" I have a feeling a lot of other people had the same initial enthusiasm when they saw the title.

    Of course then I got to the point where it's mentioned that none of the Conroes unlocked upwards. Given that the technology mentioned in this article has existed for some time, I'm not sure why the article was even put on Anandtech.
  • AdamK47 3DS - Thursday, August 24, 2006 - link

    I believe Anandtech needs to edit the article to aknowledge that Gigabyte was the first with the feature. Reply
  • Madellga - Thursday, August 24, 2006 - link

    Wesley, you probably know this (at least Gary should know it, as he has threads on the CPU Forum).

    This is not an ASUS feature - at least on the P965 boards. Gigabyte was there before.
    I have a DQ6 and the shipping BIOS F2 had it already.

    With so many people on the forum using Gigabyte (including Gary), I wonder why do we have an article based on the Asus.....
  • ZachSaw - Thursday, August 24, 2006 - link

    Exactly. The whole article has been singing in ASUS tune when in fact they've just copied someone else's feature! Shame shame.

    It's such an old feature to exploit EIST for multiplier adjustment that Gigabyte didn't even talked about it any more. Perhaps Wesley is excited ASUS has finally implemented that feature? :) ASUS fan-boy.
  • Gary Key - Thursday, August 24, 2006 - link


    Exactly. The whole article has been singing in ASUS tune when in fact they've just copied someone else's feature! Shame shame.

    This is my fault. I had a miscommunication with Wes about the unlock features on the Gigabyte boards. Asus had figured out a way to go up and down which (we are trying to find the proper lot number to test) Gigabyte and others had not at this time. In my conversations with Wes I relayed the wrong statement about Gigabyte's capability in this area or my words were confusing about the EIST exploit. Asus will also implement this capability on the 975X chipset in the near future. If the tables were turned on the manufacturer then Wes would be a Gigabyte Fan-Boy I guess......

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