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


View All Comments

  • Visual - Friday, August 25, 2006 - link

    does the non-deluxe p5b get the same oc results?
    what exactly are the differences between deluxe and normal?
  • Gary Key - Friday, August 25, 2006 - link


    does the non-deluxe p5b get the same oc results?

    No, expect around 7x430 with a very good setup and 7x450 with an excellent setup that is stable with the E6300. The main difference between the boards is the P5B-D has eight phase power compared to three on the P5B along with the Asus heat pipe cooling technology. The P5B-D has upgraded audio, components, additional x16 PCIE slot (x2 or x4 operation), dual Gigabit LAN, and a USB WiFi option along with additional SATA ports.
  • yyrkoon - Friday, August 25, 2006 - link

    How about an article for those of us who havent OC'd in a while ? Things to test, things to change in the BIOS etc? Last truely sucsessfull OC I've personally had, was a P55 233mmx intel CPU, on a ABIT board (yes, YEARS AGO).

    Anyhow, whats the impact on a system with a dropped multiplier, and increased FSB ? I'm pretty sure the longevity of said system wouldnt be as long if run stock . . .
  • daneel3001 - Friday, August 25, 2006 - link

    I've got a P5B non deluxe with a E6600 + 2GB of Crucial Ballistix PC6400.
    As I am no expert in overclocking the only thing I tried to up was the FSB, from 266 I managed to push it to 310, before that it would crash.

    Can anybody tell me settings for say going from 2.4 to 3.0 ?
    My guess is :
    FSB to 333 so core speed is 333*9=3ghz
    Up CPU voltage to 1.4v
    ..and the thing I am really not sure is the memory setting, 1. whether or not to use spd and 2. what speed to use and maybe 3. what volt to use (the Crucial is guaranteed up to 2.2v but board is limited to 2.1v).

  • Gary Key - Friday, August 25, 2006 - link


    As I am no expert in overclocking the only thing I tried to up was the FSB, from 266 I managed to push it to 310, before that it would crash.

    Have you tried the 0309 bios yet? It improves overclocking a great deal but comes at the expense of needing "good" memory capability in order to do it. Start with SPD, raise your memory to 2.1V, use the 1:1 divider, and set your CPU vCore at 1.375V, MCH around 1.45V as a start.
  • daneel3001 - Sunday, August 27, 2006 - link

    Yep tried the 0309.

    I am currently set at :
    CPU vcore @ 1.4v but showing 1.368v on CPU-Z
    Mem voltage @ 2.1v
    FSB @ 340
    Mem @ 428 (860 DDR2).

    Not sure about MCH you mentioned.

    For some reason I can't get my machine stable past 3ghz, SuperPi will be ok but Sandra burnin will crash. I'm going to try with current settings..

  • DudemanX - Monday, August 28, 2006 - link

    I also have the P5B non-deluxe using the new 0309 BIOS.

    Core 2 Duo E6600
    ASUS P5B
    4GB (4x1GB) Corsair PC2-6400 4-4-4-12

    I wasn't looking for max overclock as this chip is so fast already so I started by turning my multiplier down to 6, FSB to 400, and memory to 1:1. Worked fine without any voltage tweaks so I started upping my multiplier. I'm now running at 8 x 400(3.2Ghz) without messing with any voltage settings. I may be able to go higher but this is more than enough to drive the single video card that this board supports and I'm quite happy.

    A weird thing I noticed is that checking the ASUS site again today(Mon. 8/28) no longer has the 0309 BIOS listed. Are some poeple having issues with it or did Intel make them remove it?
  • lopri - Friday, August 25, 2006 - link

    I can't help but to think this article is some kind of a stunt, which is in line with AT/ASUS alliance. It'd make a good Inquirer article, though.
  • Black69ta - Wednesday, August 30, 2006 - link

    I seem to remeber hearing that the Conroes would be unlocked for all grades not just the extremes but intel was going to wait to do this for a little while after launch. it seems like I heard this even before they were called Core 2 duo's. maybe Intel locked the early one so that people would have a reason to buy the Extremes, I also seem to remember the extremes would eventually get hyperthreading back, maybe as a middleground between Kentsfield and Core 2 Duo? maybe this is why nvidia is putting off releasing any intel edition 590 boards because they didn't was to spend so much money on constantly having to update BIOS and this and that while the dust settles from the launch. not to mention the reputation. If they could release the Intel 590's without any Major bugs then that would make the new "oddball" chipset maker major kudos, at least compared to the Intel and Ati chipsets. Reply
  • splines - Thursday, August 24, 2006 - link

    There's a difference between being 'in the industry' and 'clobbering people over the head with my obvious superiority and subtle hints'. If people think you're coming off as arrogant, maybe you should reconsider your approach to criticism.

    I know quite a few people who know to some very important and NDA-protected facts. None of them troll the net bashing people over the head with stuff like this, because it can get you into serious trouble.

    Secondly, you never never never ever try and come across as if you're speaking for the company.

    Ever. Never ever. Is your supposedly leet job worth you seeming like a big man on a message board?

    If you're meant to be someone of importance, you're a rank amateur at keeping your mouth shut, and a liability to boot.

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