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XP2500 Barton running on 266 FSB?

Discussion in 'AMD Thunderbird' started by Rob, Sep 8, 2003.

  1. Rob

    Rob Guest

    I need to know if the XP2500 will run on the Asus barebones Terminator
    barebones system.
    The chip is not listed by Asus as a supported chip but I was wondering if it
    could run the chip at 266FSB instead of 333 ?

    I placed the order on ebuyer this evening and before I could change the
    order it was awaiting shipping so I couldn't change it.
    Ebuyer are just too efficient!

    I should have ordered the XP2400 266FSB, I have reqested the change but I am
    not too hopeful about it happening.


    Rob, Sep 8, 2003
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  2. Rob

    Wes Newell Guest

    You can set the FSB to anything you want as long as the board supports it.
    The 2500+ is rated for 50-166MHz FSB, but will work with both a higher and
    lower FSB.
    Wes Newell, Sep 8, 2003
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  3. Rob

    mdp Guest

    You can clock the bus at a lower speed, the chip won't care. However, if the multiplier is locked at 11, your speed will reduce
    from 1833MHz to 1463MHz, a 20% reduction. If the CPU multiplier is unlocked and your board can provide a multiplier up to 14
    (1862MHz), then you can still retain the raw CPU speed advantage but won't get the memory (333MHz) advantage.
    mdp, Sep 9, 2003
  4. Rob

    Rob Guest

    Thanks for the info, it's a bit clearer to me now.

    Why would it be locked at 11, if it knows the CPU is meant to run at 1833
    then surely it will set the multiplyer to 14?

    If it has an adjustable multiplyer I could overclock it to 2Ghz quite easily
    I guess. 15x133mhz = 1995mhz
    Chances are it won't let me, site does not include the DDR version of the
    The older non-DDR manual does not have the choice of multiplyer selection.
    I will need to wait and see what the manual has in it when it arrives.

    I have ordered a XP2400 CPU but that was out of stock and 5 days wait.
    Bit of a bugger if you ask me.

    Ebuyer will quite happily refund the XP2500 and postage to return it, so on
    that I cannot fault them on that.



    the multiplier is locked at 11, your speed will reduce
    unlocked and your board can provide a multiplier up to 14
    get the memory (333MHz) advantage.
    Rob, Sep 9, 2003
  5. Rob

    Ben Pope Guest

    No - the bridges on the chip set the default multiplier and FSB.

    You can change them independantly but the default is still the default.

    The processor speed is determine from the FSB * Multiplier.

    The multiplier os not determined by the CPU speed / FSB (if you see what I
    Yep (2000MHz... it should be 133.33. Mine runs a little fast though... I
    end up with 2005 (200*10))
    Oh I see...

    Well the biggest issue is that you need to go from <=12.5 to >=13, which
    requires the 5th bit of the multiplier to change. Some motherboards don't
    support this and so you will have to change it yourself... either with the
    bridges or the wire-in-the-socket mod.

    You haven't said what motherboard you have.
    I'd have kept the Barton.

    Ben Pope, Sep 9, 2003
  6. Rob

    Rob Guest

    Hi Ben,
    ASUS A7SC TriOptix form-factor
    http://www.asus.com/prog/spec.asp?m=Terminator K7 DDR
    Why, chances are it will be slower than the XP2400 in the A7SC M/B

    Yours thoughts?

    Rob, Sep 9, 2003
  7. Rob

    Ben Pope Guest

    Clock for clock the Barton is quicker due to an increased cache hit ratio
    and therefore greater memory performance.

    Ben Pope, Sep 9, 2003
  8. Rob

    Rob Guest

    Hi Ben,
    I hear what you are saying, its got double the L2 cache but its clock
    cycling is slower and the feed of data from memory through the databus is
    the same(266) due to the lack of a 333 FSB on the M/B.
    I'll go with the XP2400, but I would love a 333 FSB version of this
    barebone system. It works out as a very cheap to build system.


    Rob, Sep 9, 2003
  9. Rob

    Ben Pope Guest

    Whats clock cycling?

    Yep, agreed... with the 266 FSB you won't get the bandwidth increase that
    you'd usually get - it'll be the same as the T'bred, but the increased L2
    will still help a little. To be honest there really isn't that much between
    the two - I suspect you'll be pleased with your purchase.

    Ben Pope, Sep 9, 2003
  10. Rob

    Rob Guest

    Hi Ben,
    Cycles per second

    A quick check at this :

    This shows the XP2500 333 can beat the XP2600 266 in a lot of cases so its a
    better bet.
    But the XP3200 400 certainly aint worth all the dosh and cooling you need to
    throw at it not unless money is no object.

    I want a kick-ass PC base unit for less than 300 GBP.
    Using DDR2100, XP2400 266, 40GB Western Digital 8Mb cache HD (WD400JB), Case
    loaded with everything including an all important compact flash slot.

    So in the end you're right, the Barton XP2500 is better but I need the
    system to use it to the full at a bargain basement price.

    Nice chatting with you.


    Rob, Sep 9, 2003
  11. Rob

    CiRcUiT Guest

    Then all you do is buy a XP2500+ Barton and set it to be a XP3200+ like I
    just did last weekend. Perfectly stable at 200x11=2.2GHz (3200+ speed).
    Although I did need to up the Vcore by .025 volts (1.675 instead of 1.65) to
    make it totally stable.

    XP2500+, Aopen AK79D-400VN, 2x256MB DDR400 was less than $500 CND.
    CiRcUiT, Sep 10, 2003
  12. Rob

    Ben Pope Guest

    So final clock speed then... fine. But there's nothing stopping you from
    clocking them the same.
    Indeed it isn't. I purchased an XP2500, but have been troubleshooting the
    occasional error in Prime95 with higher FSB (been trying 200 and 220).
    You're crippling the performance by buying PC2100. 256MB of Twinmos PC2100
    is £30.50, PC2700 is £31, PC3200 is £32.50 (Tekheads.co.uk)
    Ben Pope, Sep 10, 2003
  13. Rob

    Rob Guest

    Bad news.
    The XP2500 will not post at all. No beeps or anything. :eek:(
    If I pull the mem it beeps.
    Wait till Tue for the XP2400 and check its not the m/b.

    The Asus Terminator is excellent for the money. I am really pleased with it.
    Even has "Qfan" on the case fan and CPU fan.


    Rob, Sep 13, 2003
  14. Rob

    mdp Guest

    Given that it beeps with no memory, a long beep is the correct code, I would first suspect the memory. Could be an incompatibility
    or simply bad memory. Are you able to find another stick or try another slot? The manual states it will not work with DIMMS that
    have more than 18 chips.
    Please de-spam my address if replying to me
    mdp, Sep 13, 2003
  15. Rob

    Ben Pope Guest

    Thats not really uncommon. There is usually some limit to the amount of
    current you can source from (or sink to) a bus!

    Ben Pope, Sep 13, 2003
  16. Rob

    Rob Guest

    I will need to wait for the correct CPU before I start suspecting other
    I certainly expected the XP2500+ Barton to work being as it is clocked at
    only 1826mhz, well below the XP2400+ Thoroughbread.
    It may be it is trying to set the FSB to 166 and screws up on that.

    I need to wait and see.



    would first suspect the memory. Could be an incompatibility
    slot? The manual states it will not work with DIMMS that
    Rob, Sep 14, 2003
  17. Rob

    Rob Guest

    Going back to comment about memory.
    Putting PC3200 in instead of PC2100 should make no difference what so ever.
    I did however order PC2100 with CL 2, and this is selectable in the bios.
    So the money is better spent on a lower CAS Latency.

    Snippet from the Crucial site:
    What does "CL" stand for?
    CL stands for "CAS latency," which is the number of clock cycles it takes
    before data starts to flow once a command is received. Low CAS latency is
    faster than high CAS latency. However, faster memory will NOT necessarily
    make your system faster. Your computer will only run as fast as the "slowest
    link" in your system, so you can't speed up your computer by adding memory
    that is faster than your current memory. The way to make your system faster
    is to add more megabytes (MB) of memory.

    If you're building your own system, we recommend using parts with low CAS

    So the only reasons I would choose PC3200 is:
    1. Cheaper....unlikely considering I would want a part with a CL=2.
    2. Use it a few years on a new PC....like the old upgrade path idea..just
    doesn't happen.

    So now you can see why I chose PC2100 with CL2.


    Rob, Sep 14, 2003
  18. Rob

    Ben Pope Guest

    No difference. Except that of course PC2100 runs at 133MHz, PC3200 runs at
    200MHz, giving a mere 50% increase in peak memory bandwidth.

    (Thats assuming you have a motherboard that can run at 200MHz FSB and RAM,
    and are willing to run the FSB of your CPU at 200MHz)

    After doing some research on one of your comments, I find that you are using
    the rather old KT133A.

    So yes, PC2100 is the fastest your board supports.

    And it's crippling the performance of the Barton.

    Ben Pope, Sep 14, 2003
  19. Rob

    Wes Newell Guest

    AKAIK, the KT133A chipset doesn't even suport DDR ram and max FSB is about
    145MHz overclocked. He's probably got a KT266(x) chipset.
    Cache hit rate is about 90% or more, so it's not as crippling as one would
    think except in benchmarks designed to show the bandwidth.
    Wes Newell, Sep 14, 2003
  20. Rob

    Ben Pope Guest

    Quite possible, my search for Asus Terminator turned up this page:

    Which shows that it uses the KL133A, which I misread as KT133A.

    Navigating from the main page gives the Terminator K7 DDR:
    http://www.asus.com/prog/spec.asp?m=Terminator K7 DDR

    Whcih actually uses SiS 740/SiS 962L with support for PC2100 and PC1600.
    Thats entirely application specific - I have no numbers myself. It sounds
    reasonable for running most code.

    I didn't see the point in running with PC2100 when PC3200 is not that much
    more expensive - but since he is using a motherboard that does not support
    Ben Pope, Sep 14, 2003
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