The Pentium-D 820 mystery -- apparently not compatible with nF4-SLI (Intel) chip-set ....

Discussion in 'Gigabyte' started by John Lewis, May 30, 2005.

  1. John Lewis

    John Lewis Guest

    For background see page 4 of the following article:-

    http://www.xbitlabs.com/articles/cpu/display/pentiumd-820.html

    There seems to be a FUNCTIONAL problem with the nF4-SLI(Intel)
    chip-set if both cores of the Pentium-D 820 are enabled. Applications
    crash or hang, the motherboard re-boots... However, the current
    explanation given to Xbit Labs by nVidia is that " we only support the
    830 and above - the 820 is too slow for enthusiasts" . Zero technical
    explanation for the problem...and a bad answer anyway. Many
    enthusiasts that I know buy the least expensive and overclock. None of
    the nF4-SLI (Intel) motherboards that claim to support the Pentium-D
    mention any exclusion of the 820 in their specs. And Asus seemed to
    have been caught totally off-guard by the problem, considering their
    reaction as reported by Xbit Labs.

    So:-

    (a) Did nVidia commit a design blunder ?

    If so, I would be highly suspicious of stable performance with
    the Pentium-D 830, the next one up in the family. One way to
    check for a design blunder by nVidia would be to underclock
    the 830, or 840, or Pentium Extreme 840 to 2.8GHz -- particularly
    the 840 Extreme, since it has unlocked clock dividers--- in the
    same nF4-SLI motherboard(s) in which the Pentium-D 820 fails
    and see if they all remain stable. Nobody with access to these
    parts has yet done this..........

    OR

    (b) Did Intel slip something into the P-D 820 unknown to
    nVidia that would ensure that their least-expensive, highest
    volume dual-core would only work on Intel chip-sets, and just
    supply the faster parts to nVidia for their chip-set
    qualification ??

    OR

    (c) Is this physical incompatibility part of the chip-set agreement
    between nVidia and Intel to minimise the opportunity for
    nVidia to take over the Intel dual-core compatible chip-set
    market at a critical time for Intel in terms of chip-set
    supply ? The Pentium-D 820 is likely to be the highest
    volume dual-core part in the Intel stable.

    Remember, unlike AMD, Intel dual-core requires a new
    motherboard/chip-set for each dual-core processor shipped.

    Maybe the cure is as simple as adding 820 support in BIOS -
    since the 820 implementation is not exactly the same as the 830
    and 840. However, Asus seemed to be caught unawares by the
    problem and nVidia's denial of a fix.

    There is no obvious difference between the 820 and its faster brothers
    that would explain the failure. Yes, it uses a lower-value clock
    multiplier and does not implement Speed-Step, but that is a
    functionally-identical state to a P4-2.8 single-core Prescott.

    Does that mean that a single-core 2.8 GHz processor would also fail in
    an Intel nF4-SLI board ? Probably not, since the P-D 820 with one core
    disabled works fine. ( The nF4-SLI chip-set is supposed to be
    compatible with both single and dual-core LGA775 processors )

    Anyway, for the moment, until this thick smoke-screen by nVidia and
    Intel clears, I would highly recommend holding off purchase of any
    nF4-SLI (Intel) motherboard, regardless of processor initially
    installed -- single, or dual-core - if you are expecting the MB to
    eventually function with a dual-core processor. I notice that
    the very fine MSI P4N Diamond MB (with software-switching of
    SLI, and embedded Creative 24-bit audio) is currently available
    from Newegg @ $229. This board is potentially affected by the 820
    problem... no comments from MSI, so far.

    John Lewis
     
    John Lewis, May 30, 2005
    #1
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  2. John Lewis

    Paul Guest

    As for Asus, they get a "weasel" rating, in terms of letting
    the limitation of the P5ND2 be known. The motherboard page with
    specs for the board is here:

    http://usa.asus.com/prog/spec.asp?m=P5ND2-SLI Deluxe&langs=09

    "Supports Enhanced Intel SteepStep Technology(EIST) Intel
    dual-core new generation CPUs enabling ( subject to Intel CPU
    availability and NVIDIA chipset supportability )"

    Would you buy a used car from the person who wrote that ?
    Are we supposed to guess at just what "supportability" means ?

    The Asus FAQ page has an entry for the 820 vs P5ND2 issue. The
    downloadable Asus motherboard manual also has a statement
    in the specification section, that the 820 runs in single
    core mode only. So, Asus has "confessed" in as invisible
    a way as they can manage (no one visits the FAQ page because
    it is so crappy and pointless). The CPU support page is completely
    silent on the subject of dual core processors for the P5ND2,
    which is also peculiar (only the P4-670 3.8GHz processor is
    listed?). I don't think the Asus support page is ready for
    duals yet (the P5WD2 has no processors listed).

    As for the differences between chips, the 820 doesn't have
    EIST (it probably does have it, but it is useless, as the
    idle speed and full-power speed would both be 2.8GHz, which
    means no change between states). Another difference on the
    820, is it is the only 05A power spec processor, and the
    PRB (processor requirements bit) in the MSR is zero for this
    processor. Which should be a "no sweat" issue (BIOS is supposed
    to read this bit, and only has to respond in some unexplained
    way, when PRB=1).

    While there are a pile of errata in the Intel datasheet, there
    is nothing in there that is suggestive of a failure mechanism
    (doc 30683203):

    http://www.intel.com/design/pentiumxe/specupdt/306832.htm

    Perhaps you could drop Wesley Fink at Anandtech a line, and
    see if he knows whats up.

    Paul
     
    Paul, May 30, 2005
    #2
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  3. John Lewis

    John Lewis Guest

    Paul,

    Thanks for the truly excellent information. I have sent Wesley an
    email as you suggested. I hold Anandtech in very high regard,
    so I am optimistic that we shall get the true story very soon. Will
    post any reply here, if appropriate. AnandTech may decide to
    investigate formally and publish an article on the subject. Wesley's
    first reply to me might just be his own initial speculation and
    pointless to post here. We don't need to fuel more rumors on the
    subject -- we need the facts !


    John Lewis
     
    John Lewis, May 30, 2005
    #3
  4. John Lewis

    John Lewis Guest

    www.monarchcomputer.com is now taking pre-orders on
    a first come, first-serve basis. First shipments due June 16.

    All 4 variants of the X2 processor too !!

    Unit prices as follows:-

    X2 4800+ $999
    X2 4600+ $822
    X2 4400+ $619
    X2 4200+ $579

    I would expect Newegg to be about 5-10% lower
    (except for the 4800+) once they open up for orders.
    Newegg does not take pre-orders.

    Looks as if AMD is beating Intel to the RETAIL market
    in dual-core. AMD appears to be executing their desktop
    (and server) processor strategies with perfection these days,
    while Intel is stumbling around in darkness of their own
    making.

    ( Intel dual-core will need a new motherboard, DDR2
    a beefier power-supply plus a bunch of extra cooling..... )

    Think of all those Socket 939 motherboards waiting to
    be upgraded (especially the SLI ones..) -- provided the MB
    manufacturers pull their fingers out in offering BIOS upgrades
    to support the X2 !!!

    For the X2 to work reliably, the Socket 939 MB should
    have A64 4000+ or FX-55 power-regulator capability.

    I expect initial shipments to be small and heavily over-
    subscribed.

    John Lewis
     
    John Lewis, Jun 1, 2005
    #4
  5. John Lewis

    NightSky 421 Guest


    I won't be buying a new computer until next year, but hopefully these sorts
    of processors will have mainstream pricing by then. I'm pretty confident
    they will.
     
    NightSky 421, Jun 1, 2005
    #5
  6. John Lewis

    John Lewis Guest

    Seems as if big-brothers Intel and M$$ have our true interests at
    heart :--

    http://www.digitmag.co.uk/news/index.cfm?NewsID=4915

    In the case of Intel "pride (arrogance) may come before the fall"
    The Pentium-D is already architecturally in deep trouble; why add
    this extra burden ?? No doubt depending on Dell's volume and its
    technically-naive customer-base to help dig them out for at
    least the next year.

    John Lewis
     
    John Lewis, Jun 1, 2005
    #6
  7. John Lewis

    Rick Guest

    How do the concerns expressed in this article equate to
    anyone being a "DRM paranoid"? But in any case thanks
    for the link.
     
    Rick, Jun 1, 2005
    #7
  8. John Lewis

    ringfinger Guest

    Wow. I had no idea DRM was embedded in the new Pentium D and chipset
    of the 9100. I was seriously considering buying one online today too
    but figured I'd come check the trusty forums on everything first.
    What will DRM embedded into the chip effectivly mean to the home user
    who already has copyrighted materials on hard drives, say externally
    and trying to copy internally? The chip sounds great other then all
    this big brother junk. How does the pentium d stack up against a P4
    w/ HT?
     
    ringfinger, Jun 1, 2005
    #8
  9. John Lewis

    Kroagnon Guest

    Hyperthreading is the only thing making me still buy Intel P4s for server
    use; from now on it's Athlon 64 x2 for me (when price comes down).
     
    Kroagnon, Jun 2, 2005
    #9
  10. John Lewis

    John Lewis Guest


    Similarly. For lots of excellent reasons other than DRM.

    Any so-called "enthusiast" who buys one of the current-generation
    Intel dual-core processors (or Intel-based dual-core desktop systems)
    should have his/her head examined for embedded sawdust.

    John Lewis

    ( I have only ever built/used systems with Intel processors
    up to this point..... )
     
    John Lewis, Jun 3, 2005
    #10
  11. John Lewis

    tlai909 Guest

    Besides DRM, what's wrong with Prescott and -D 820?

    Not that I care because the only Intel I've paid for is PIII and
    Pentium-M...

    T.
     
    tlai909, Jun 3, 2005
    #11
  12. John Lewis

    John Lewis Guest

    How would you like an inefficient room-warmer ? For a start.

    See Anandtech and Xbit Labs articles on dual-core
    processors. And if you want to really get into
    it technically.. read the recent Xbit Labs articles on Intel
    Netburst. You are lucky to have PIII and Pentium-M.
    Both excellent architectures.

    John Lewis
     
    John Lewis, Jun 3, 2005
    #12
  13. John Lewis

    Conor Guest

    The fact that you'll not be able to get it running at full whack for
    long periods because it'll overheat and slow itself down.
     
    Conor, Jun 3, 2005
    #13
  14. John Lewis

    Bob Guest

    My son runs a 3.2 GHz P4 Prescott with a Zalman copper heat sink

    http://www.directron.com/cnps7700cu.html

    and the CPU temp stays below 40C. The retail box cooler was a joke.
     
    Bob, Jun 3, 2005
    #14
  15. John Lewis

    Conor Guest

    Very good. Now try running 3DMArk05 CPU test in a constant loop and see
    how long it is before the speed drops.
     
    Conor, Jun 3, 2005
    #15
  16. John Lewis

    John Lewis Guest

    With a Zalman Cu, the 3.2GHz P4 Prescott should be fine.
    However try with the same heatsink and running 2-thread CPU stress
    on the Pentium-D 820......slow-down pretty-well guaranteed without
    additional forced-air cooling of the heatsink. Intel, in their great
    big-brother wisdom even deliberately left the power-saving SpeedStep
    out of the P-D 820. Must be afraid that people will try to overclock
    their least expensive offering instead of buying the higher members
    of the P-D family.

    Intel's current bumblings and arrogant big-brother activities with
    their desktop processors deserve reward. I hope AMD takes a big
    chunk of this business. Dell will continue to bale Intel out no doubt,

    although Michael must be getting very uncomfortable --- especially
    on the rapidly-growing server side of Dell's business, where the
    Opteron is now the obvious choice from a performance/power
    point-of-view.

    John Lewis
     
    John Lewis, Jun 3, 2005
    #16
  17. John Lewis

    Bob Guest

    If he pins the CPU at 100% (according to Task Manager) when he rips
    DVDs, why would running a CPU stress utility be any different?
     
    Bob, Jun 3, 2005
    #17
  18. John Lewis

    Bob Guest

    Has anyone consulted the Patriot Act to see if there is a requirement
    for this mandated by the federal govt.

    Actually the govt doesn't need any Act to do whatever it wants. For
    example Congress passed the so-called Brady Law which was responsible
    for "Instant Checks" on a prospective gun buyer's background. The law
    stated explicitly that the govt (in this case the FBI) could keep the
    information about the buyer for 48 hours then it had to destroy it.

    Fast forward a year or so and we discover that the FBI is blatantly
    breaking the law by keeping data on gun buyers processed by the
    Instant Check system. So the NRA takes the FBI to court and the case
    works its way up to the US Supreme Court.

    The US SC ruled that the FBI could continue to their practive of
    keeping information even though it is explicitly outlawed by Congress.
    That's because it is the "right" of the FBI to do whatever it damn
    pleases. Nevermind it completely ignored all the warnings about 911,
    including a delegation of intelligence people working for the Massoud
    who came to Washington personally to show the FBI its intelligence
    gathering. No one would see them when they arrived.

    The point of all this is there is ample precedent for the govt acting
    like a fascist dictatorship with the full blessing of the highest
    court in the land. And Intel is just doing its part to fight
    terrorism. HA!

    Anyone remember Richard Jewell? Or Ruby Ridge? How about the Waco
    Massacre? Can you say "Seig Heil!". There, I knew you could.

    Intel: "Big Brother Inside!"
     
    Bob, Jun 3, 2005
    #18
  19. John Lewis

    Kroagnon Guest

    Heat and power consumption on the Prescott.

    As for the P-D there are similar heat and power consumption issues and I
    believe that it also lacks x64 capability.
     
    Kroagnon, Jun 3, 2005
    #19
  20. John Lewis

    Bob Guest

    There is a lot more to this than a company shooting off its feet.
     
    Bob, Jun 4, 2005
    #20
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