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Modding The Barton XP To A Barton MP

Posted by timothy on from the who-needs-a-warranty dept.

Dr. Jackie Lee writes "Don't have the budget for an AMD Opteron? There's always a cheaper alternative with AMD's current Barton processors. In this article, we'll show you how to run these new Barton XP processors in SMP mode."

11 of 172 comments (clear)

  1. Hmf by BJH · · Score: 4, Insightful


    Yeah, great - mod your XPs to act like MPs.

    Guess what? You can't guarantee they'll work - people on LKML have refused to help users who have done this, as it simply makes it impossible to determine whether problems are the fault of the kernel or of the CPU itself.

    This is one for the overclockers who couldn't care less about stability, methinks...

    1. Re:Hmf by beuges · · Score: 5, Insightful
      This is one for the overclockers who couldn't care less about stability, methinks...

      Or, maybe, its for those of us who can't afford the hugely expensive 'multiprocessor' chips, but would still like to be able to run a dual-processor system.

      As a programmer, it's always a good idea to have access to a dual-processor system, because there are all sorts of lockups that just wont happen on a single-processor system, but will lock your program up on a multi-processor one. Having a hugely expensive system just to debug an application isn't feasible - if you're able to fool a 'single processor' chip into thinking it's a 'multiprocessor' one, then you've got an essential debugging machine at a fraction of the price

    2. Re:Hmf by cowbutt · · Score: 4, Insightful
      Er, no, because then you end up wondering whether it's your bug or a hardware problem.

      A friend spent a long time debugging some maths in a game engine he's working on. First of all, he assumed it was his code, then after eliminating that possibility, assumed it was a gcc bug, then eventually found that the problem was caused by the motherboard's voltage settings being incorrectly documented and therefore he'd mistakenly configured it to supply the CPU with the wrong voltage.

      --

    3. Re:Hmf by theLOUDroom · · Score: 5, Insightful

      Guess what? You can't guarantee they'll work - people on LKML have refused to help users who have done this, as it simply makes it impossible to determine whether problems are the fault of the kernel or of the CPU itself.

      Bah. You don't know anything for sure, neither to these LKML people. They're just trying to eliminate unknow quantities from their debugging (not like I blame them). For all we know right now (being that the article is slashdotted) there is no difference between the XP and MP except a jumper setting. I honestly wouldn't be suprised if it's true. Why go through all the trouble to fab seperate chips when you can just use external jumpers?

      This wouldn't be the first time someone could upgrade their hardware by connecting two contacts.

      What really matters is determining if there is any actual difference between an XP and an MP. If there is none, then this isn't just for "the overclockers who couldn't care less about stability". There are plenty of others who would love to save $40/cpu.

      Since you don't know either way. You're not really contributing much to the discussion. Yeah, without any testing I wouldn't use a modded chip for critical data, but it's not impossible to verify whether or not the modded chip is stable. "it simply makes it impossible to determine whether problems are the fault of the kernel or of the CPU itself" No, it doesn't. There's a simple solution. Test with both modded XPs and regular MPs.

      What needs to happen is testing. Without that, we don't really know how useful this mod will be.

      --
      Life is too short to proofread.
    4. Re:Hmf by afidel · · Score: 4, Insightful

      Actually it's bridges on the package that make the difference, AMD laser cuts the SMP bridges on Barton core cpus that are intended to be XP's, these can be either failed MP chips, or much more commonly they are just XP's that were never tested for SMP compliance because the extra testing would take time and additional testing equipment. The problems introduced by running SMP XP's are that the quality of connecting the bridges varies greatly and is never as good as the origional connection that was laser cut, and the fact that you may have a core that AMD already rejected because it failed to work correctly in their SMP tests.

      --
      There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
  2. Re:Possible DMCA violation? by fadeaway · · Score: 4, Insightful

    You trade your warranty for the modification. Sounds fair to me.

    There's no EULA for hardware.. yet..

  3. Reasons for SMP by lingqi · · Score: 4, Insightful

    not trolling, but a serious question, coming from a ex-SMP-user:

    why SMP nowadays?

    Most OS, including XP, is now reasonably stable to the point where multitasking, including buring a CD, while doing something else is OK. (not to mention that CD burners have buffer under-run protection *anyhow* nowadays) I know this because my laptop, which is a measly P3, can handle all of the multitasking I do, given that I have pumped up the amount of RAM.

    If I was doing stuff for school / research, Mathematica, Matlab, Maple, Spice (ok not 100% sure on spice) are all single processor only. And to be honest, if you are running a 3-day simulation, you really don't want to be playing UT at the same time on the same machine ANYWAY, so that's kind of a moot point. (you should probably not be playing UT period during such times, but that's a time management story that i won't get into)

    If I was doing real work like rendering stuff, I think real work deserves a real SMP system, i.e. with a warrenty.

    I mean, SMP has a pretty hefty price overhead (motherboard, memory if you want ECC, and the extra CPU, heavy duty power supply, another set of heatsinks etc), not to mention that the motherboard / chipset technology is usually a few monthes to two years behind the cutting edge stuff...

    so, what convincing reason do a person have for using SMP right now (especially a ghetto-rigged one)?

    --

    My life in the land of the rising sun.

    1. Re:Reasons for SMP by kaamos · · Score: 2, Insightful
      It really has to do with the bragging rights. I agree, right now I Maple all the way trough my math courses and it is plenty fast on a p3 1.13.

      The only way I could justify this to myself is if I picked up 3dsmax again ON A PERSONAL BASE, ie. not getting paid for it, just for fun, and if the motherboards were cheaper, then it could be fun just for the hell of it.

      On a side note, how is the volume of sound generated by smp systems, you being an ex-SMPer? I was thinking maybe dual vantec tornados 7 turned all the way down...

      --
      In Canada, we don't fancy things like socks
    2. Re:Reasons for SMP by Brento · · Score: 5, Insightful

      why SMP nowadays?

      Sadly, there's still a lot of dog-slow apps. Example: ask Macromedia Dreamweaver MX to test a stored procedure with a hundred parameters, and it'll freeze for 30-90 seconds on all of the P4's I've tried it on, pegging the CPU at 100%. On dual-CPU boxes, that means you can still be productive with the other CPU, and do things like whine on Macromedia user groups while it runs.

      SMP also helps a lot if your box is both a testbed and a design system: mine runs SQL Server, IIS, and I do my design on it, so while I'm working, there's a ton of processes running.

      Don't get me wrong, I still buy the "real" SMP systems with warranties, but just pointing out why I'm doing it, and I'm not rendering.

      --
      What's your damage, Heather?
  4. screw that by joss · · Score: 1, Insightful

    Now that P4's have hyperthreading I think it makes much more sense to get one of those. That way you dont need a tornado in your box to keep things cool and you get 80% of the benefit of dual processors.

    --
    http://rareformnewmedia.com/
  5. Y'all are forgetting something by AntiBasic · · Score: 2, Insightful

    Techies all know that these two CPUs are the same, right? They're wrong.

    It's true that the Athlon MP and XP are built as identical cores at the fab. In fact, you can tweak your L5 bridges on your Athlon XP to enable support for dual processors. Nonetheless, this still doesn't mean they're the same thing. Have you ever wondered why the Athlon MP lags behind the Athlon XP in megahertz? The flagship Athlon MP is only at 2800+ while Athlon XP is at 3200+...

    Athlon MP's are binned Athlon XP's. No two CPU cores fabricated are absolutely identical, and the Athlon MP represent AMD's best product. The goal for the MP line of chips is to have lower temperatures for the same megahertz. This makes their clock ramp-up fall behind the Athlon XP line. Stability is the obvious benefit, however recall also that rackmount servers don't have the same exotic cooling solutions that your desktop may have. Binning is one way AMD ensures a superior product for multi-processor systems. The other way AMD ensures the MP lineup is reliable is that the first Athlon MP 2800+ is going to have a later CPU stepping than the first Athlon XP 3200+.