Dell Dimension 8400 CPU upgrade

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Dell Dimension 8400 CPU upgrade

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New to this forum - any assistance would be appreciated.

I currently have a Prescott Pentium 4 540 CPU 3.2GHZ (SL8PY ??) with an OJ3492 motherboard and 925X chipset. I understand from reading previous posts I should be able to upgrade to any Prescott Pentium 4 6x0 series giving me then 64 bit operation, however when I look at the Prescott 6x0 series they say that compatible chipsets are 945G and 945P. Does this mean I am snookered or are they backward compatible?

I can't seem to find a P4 6x0 series compatable with 925X chipset. Or am I looking for the wrong thing?

Ron.

Verified Answer
  • munro284

    You can upgrade to any Socket LGA775, 5xx, 6x0 or 6x2 processor, with 90nm architecture, but not the 6x1 processors.

    The 670 3.8Ghz is the largest.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

All Replies
  • munro284

    You can upgrade to any Socket LGA775, 5xx, 6x0 or 6x2 processor, with 90nm architecture, but not the 6x1 processors.

    The 670 3.8Ghz is the largest.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Thanks for that Bev.

    Assume they are all compatible with 925X chipset.  BTW do you think I may need to boost the PS?

    Ron.

  • munro284

    Yes, they should be compatible,

    I installed a Socket LGA 775, 660, 3.6Ghz processor in one of my Dimension 8400 with a 925x chipset, without issue.

    Prior to installing the processor, check that you have BIOS Version A09 installed, when support for newer processors was added.

    There's no need to upgrade the power supply, for a processor.

    Remember to clean the heatsink's base and replace the thermal compound.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Bev,

    Thanks for all that - CPU ordered and keeping fingers crossed......

    Ron

  • munro284

    Ron,

    You are welcome and good luck with the upgrade, please post back with results.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • I have a 3.2 cpu installed in a 8400 IF i install the highest speed cpu available will i see any difference in performance or is the difference to small to notice and therefore time for a new machine, i have installed win 7 32bit which runs ok but we all need more speed don't we.

  • JIMPYS

    You should see a small increase in performance, but may not be worth the cost of the upgrade, as only single core processors are supported by the 8400

    Maxing out the RAM would be a better upgrade and maybe the video card, depending on what PCIe x16 card, that's installed now.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • JIMPYS,

    Agree with Bev - there is a very small increase in performance but that is offset by the increased fan noise - see my post  "Dell Dimension 8400 CPU upgrade - Success".  The cost of the upgrade was just a couple of pounds but I eventually reverted to the original CPU because of the fan noise. Now looking for a 650 CPU that will give me 64 bit operations, or perhaps a new box.........

    Ron.

  • Many thanks guys, I have allready updated video card (Radeon 5570) & 4GB Ram some 12 months ago running Windows 7 32 bit So looks like digging into piggy bank and looking for new machine need fast machine to process large files in photoshop

  • JIMPYS

    You are welcome and upgrading to new system is a smart decision.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Hi Bev,

    I read this thread while looking at Intel's web site and I am a little confused and hope you can help get me straight. You said in this post that any 5XX, 6x0, or 6x2 processor can be used on the 8400. You also said that the 670 is the largest supported, my question is why can't I use the 672? If I understand the codes you have outlined wouldn't that fit in the category for the 6x0 processor? One more question, does it matter if the chip is made with a 32bit or 64bit instruction set?

    Thanks for your time

    RichKiroy

  • RichKiroy

    The 672 should be compatible, it's specs, are identical to the 670, the only difference is the 672 was released at the end of 2005, after Dell ceased the production of the Dimension 8400, I purchased my 8400 in January 2005.

    No, both support 64-bit/32-bit systems.

    Note: Prior to installing the processor, check that you have BIOS version A09, or higher, when support for newer processors was added.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Those processors support both 64/32 bit systems? Good to know.  I have a few questions if you don't mind my asking.

    Is the motherboard limited to 32 bit?  I was always told I couldn't upgrade the processor to 64 bit because the motherboard wouldn't support that.  It'd be great if I could, I happen to love my old 8400.  

      My second question is about Window 7 & r

    Basically I'd like to do what was asking about--try the fastest cpu I can get for this computer.  It already has max ram, higher watt PSU & graphics card added over the years so there are a few odd years of life to it yet..   I am at BIOS A09 {and what ever the last upgrade to that was} so I should be good.  I'm curious where you have found the 670 CPUS because the only processor I have been able to find was the one I already have {P4 3.4ghz which is a 550 I think}.

    you have the 660 installed did it cause your fan to run louder like Munro284?   672 might make the fan run louder?  or does it just need a different fan?  Just wondering if the fan running louder is a symptom of something else.  Thanks in advance :).

  • AboveDaClouds

    670 CPU's got on ebay from HK - If you google "Tangaishi 670 CPU" you should find him. I returned my 670 to him without any quibbles.

    Ron.

  • AboveDaClouds,

    The Dimension 8400 has either an Intel 925X Express or Intel 925XE Express motherboard. (you can use the program 'Cpu-z' to find out which yours has, if you are unsure). The 925XE is slightly better. Not 100% sure what determined which motherboard you got initially, maybe it was the processor you ordered in it, I've also read that later manufactured 8400s got a 925XE and earlier ones a 925X. My Dimension 8400 (purchased summer 2004) has a 925X.

    Both of these motherboards offer 64 bit support, so provided you use a 64 bit capable processor you can run a 64 bit OS on your Dimension 8400. (Pentium 4 processors 620, 630, 640, 650, 660, 662, 670, 672 and the Pentium 4 Extreme Edition 3.73Mhz all offer 64 bit support and are compatible with the Dimension 8400).

    The Pentium 4 670 and 672 are probably the fastest processors for the Dimension 8400, they are basically the same except the 672 has hardware virtualization support built in. (Actually the  Pentium 4 Extreme Edition 3.73Mhz may offer better performance overall because it is capable of 1066 FSB even though it has a lower clock speed than the 670 and 672... but only the 925XE offers support for 1066FSB, the 925X is limited to 800 FSB. So it won't even possibly offer any advantage if you have a 925X board.)

    I upgraded the processor in my Dimension 8400 to a 670 years ago. For what it's worth, I didn't notice an increase in fan noise.