E6850 and VMCH/FSB/tRD do the Disco


6x548FSB


7x544FSB


7x548FSB


8x500FSB


9x445FSB


We ran a series of quick stability tests using OCCT. Although OCCT will pass at a speed of 6X548 FSB with as little as 1.41VMCH, stepping up to the 7x multiplier requires a significant increase in MCH voltage. Interestingly enough, backing off a mere 4MHz on the FSB (to 544MHz) brings the MCH voltage down to 1.54V.

Using anything beyond 544 FSB requires an absolute brute force approach to get the board stable enough to generate more than a few screenshots. Lower multiplier locked CPUs will naturally need these higher FSB speeds to acquire high processor overclocks to match CPUs with higher or unlocked multipliers.

This is assuming the processor itself is capable of running high FSB speeds, and finding those is about as tough as doing the foxtrot with a Sumo wrestler. Let's move over to the E8500 and see what happens to the achievable FSB rates. We will also compare performance points between multipliers and FSB speeds.

Two-Stepping with the Test Bed… Quickstepping with the E8500
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  • AndyKH - Thursday, February 28, 2008 - link

    When reading the article, I didn't find any info on how you adjusted tRD. I thought such adjustments weren't available in the BIOS except for certain X48 boards from ASUS (unless you resorted to FSB strap settings that might limit memory ratios). Is this setting beginning to show up on X38 boards as well?
  • Rajinder Gill - Thursday, February 28, 2008 - link

    There is a full BIOS guide for this board here (part of the full review).. 'Transaction Booster' is the function.


    http://www.anandtech.com/mb/showdoc.aspx?i=3172&am...">http://www.anandtech.com/mb/showdoc.aspx?i=3172&am...

    regards
    Raja
  • Aurhinius - Thursday, February 28, 2008 - link

    I'd be interested to see something like this done with a Max formula board. Takes the X38 and pairs it with DDR2 rather than DDR3 which is still out of sensible reach for most people due to price.

    Then you can compare memory performance and settings on the same chipset with the two types of memory. Throw a quad in to the mix as well.

    It's also going to illuminate any benefits (if there are any) of moving to an X48 platform from an X38.

    Keep up the great work. These articles are a world apart from anything else I have seen and has people thinking how they evaluate their systems at all levels of experience.

    Well done!
  • Rajinder Gill - Thursday, February 28, 2008 - link

    A DDR2 version will be incoming, as well as X48 asap. We have a few reviews to get done first, but will try to incorporate this form of testing into them..

    regards
    Raja
  • Zak - Wednesday, February 27, 2008 - link

    Nicely written indeed but I gave up on overclocking, the real life benefits are not worth the effort. My 3GHz C2D runs at 3.6GHz easily with Tuniq Tower. Do I notice any difference in games? Photoshop? Nope. I used to get more excited about o/clocking I guess it passed with age:) Good luck to everyone though:)

    Z.
  • Nickel020 - Tuesday, February 26, 2008 - link

    I quite like the recent articles, that kind of quality infos & analysis is very rare.
    I also liked the inclusion of some real world benchmarks, although the tRD article was great, I was missing some benchmarks demonstrating the real world effects.

    Only thing is that DDR3 is still not an issue for most people, but the article is still well worth reading since since it explains underlying factors that affect performance.
  • menting - Tuesday, February 26, 2008 - link

    the author questions why some memory manufacturers sell CAS9 DDR3-1900 as "performance memory" even though it means it has pitiful cas latency. The reason is that "performance" cannot be judged by cas latency alone. Sure with a low latency you can get a burst of data quicker, but with back to back reads on a memory, a higher clock speed is better. So it all depends how you want to look at it and how applications make use of the memory.
  • Rajinder Gill - Tuesday, February 26, 2008 - link

    Hi,

    I would still rather buy performance parts that scale to Cas 7 at ddr 1800 than Cas 9 at DDR 1900+. The FSB/tRD and VMCH requirements just don't make intelligent sense. Then we have the 2N command rate to play with when we begin to scale much past DR-1900. I would call it a lose-lose situation.

    regards
    Raja

  • Griswold - Tuesday, February 26, 2008 - link

    Disco Stu likes the style of this article!
  • Samus - Tuesday, February 26, 2008 - link

    An unusually written article if I've ever seen one ;)

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