Dimension 8400 Processor & Motherboard

I'd stay with that CPU as I think it is th max speed anyway.

Work on improving your cooling. Start by cleaning the bottom of the heatsink and top of CPU. This can be done easily with rubbin alcohol. Next apply new thermal paste. Arctic Silver is the best by far and I use the Ceramique one.

If that does not improve the cooling do some research on compatible heatsink/fan combos preferably one that runs quiet.

Roxie2401

Yes, you can still buy Dell OEM 8400 motherboards.

You can upgrade to any Socket LGA775, 5xx, 6x0 or 6x2 processor, with 90nm architecture, but not the 6x1 processors.
8400 systems do not support dual core [Pentium D] or Core 2 Duo processors.

The 670 3.8Ghz is the largest.

I have a 660 3.6GHz processor in my 8400.

My 8400 had the noise problem, but instead of using a replacement Dell heatsink, I carried out the following: Installed a Zalman 'CNPS7700-Cu' 918gram [2+lbs] copper heatsink, with a 120mm fan, while the installation was not quite as easy, as described HERE, it is still doable and works well.

Bev.

Hi - thanks for the prompt response.  I'm curious - is it possible for the heatsink to move slightly (by opening the case and blowing the dust out, or adding more memory, etc.)?  If that happens, then, if I understand correctly, remove the existing heatsink, clean both the sink and the top of the processor chip, add the Arctic Silver, and reseat the heatsink???

Bev,

Thanks.

First, how do you correctly identify the motherboard?  I have my original Dell shipping inventory, but they didn't list the motherboard.  I was guessing it was a Foxconn - but you seem to think Dell would know my correct MOBO?

Second, what exact processor did you mean when you said you had the "660 3.6GHz?"  Is it Intel?  Where are they available?  What do I have now?  I know its 3.2, but what does the "660" mean?

By the way, my fan issue was the "Steady Amber light and fan speed like a jet engine and no POST.  It has settled down for now, but I have no idea why this happened.  Scared the heck out of me.

Roxie2401

No, the heatsink can only move, if it's not properly connected to the motherboard.

Bev.

Roxie2401:

Bev,

Thanks.

First, how do you correctly identify the motherboard?  I have my original Dell shipping inventory, but they didn't list the motherboard.  I was guessing it was a Foxconn - but you seem to think Dell would know my correct MOBO?

Second, what exact processor did you mean when you said you had the "660 3.6GHz?"  Is it Intel?  Where are they available?  What do I have now?  I know its 3.2, but what does the "660" mean?

 By the way, my fan issue was the "Steady Amber light and fan speed like a jet engine and no POST.  It has settled down for now, but I have no idea why this happened.  Scared the heck out of me.

Roxie2401

Yes, it's an Intel, that's the only brand of processor the 8400 supports.  I purchased mine on eBay, it was a 'pull' [used].

You can use a small free utility called CPU.Z, that can be download from HERE.

It will identify the motherboard as a Dell and give the model number.  The motherboard is a Dell, made by Foxconn for Dell, to their proprietary specifications.

Bev.

Bev,

The utiltiy is great!  Thanks.  So, if my processor is a 540 and yours is a 660, what changes will I see?  Is it faster?  Does it get just as hot as the one I have now?  Can I use the same heatsink if I don't do the modification you did?  And, when I look on eBay, what do I ask for?  Intel, Pentium 4, 660?  Is it a Prescott, too?

Unrelated, but did you upgrade your graphics card?  Mine is still the X300 ATI that came with the box.

Bev,

One final (I hope) question - do you have a good utility suggestion for testing memory?  I keep wondering if some of my excessive processor occupancy may have been due to a bad ram area?  Could be way off base, but was wondering if there is a way to test the memory.

Have a great evening and thanks for all the help.  Glad to know someone else is still using the 8400.

Roxie2401:

Bev,

The utiltiy is great!  Thanks.  So, if my processor is a 540 and yours is a 660, what changes will I see?  Is it faster?  Does it get just as hot as the one I have now?  Can I use the same heatsink if I don't do the modification you did?  And, when I look on eBay, what do I ask for?  Intel, Pentium 4, 660?  Is it a Prescott, too?

 Unrelated, but did you upgrade your graphics card?  Mine is still the X300 ATI that came with the box.

 

Roxie2401

THIS should give you all the information needed to buy the correct processor, 660 is the Intel processor number.

Yes, you can use the same heatsink, but some the Dell 8400 heatsinks were defective.

Yep, the X300 was the basic graphics card Dell installed, mine is a PCIe Radeon X800GTO, but there are better cards on the market now.

Bev.

Roxie2401:

Bev,

 One final (I hope) question - do you have a good utility suggestion for testing memory?  I keep wondering if some of my excessive processor occupancy may have been due to a bad ram area?  Could be way off base, but was wondering if there is a way to test the memory.

Have a great evening and thanks for all the help.  Glad to know someone else is still using the 8400.

Roxie2401

Define memory test?

If just mean, testing the RAM, then THIS this is a good comprehensive memory diagnostic.

Bev.

Ps. The 8400 is one of several systems I have, the latest is Inspiron 530 Mini Tower with a Core 2 Duo processor.

Bev,

Yes, it was the memtest that I was looking for.  Thanks.

Just to follow-up - what did you mean when you said "some of the Dell 8400 heatsinks were defective?"  If I take mine out, blow the dust out, clean the bottom & the top of the cpu, reapply thermal grease (Artic Silver), should I be ok?  What was defective?

In looking at the fan modification you did, would an original Intel heatsink/fan combo work?  I found this one on e-bay.  Its not for the 540 but how would it compare to the existing "tower" heatsink and fan? (Sorry, I don't know how to insert a link.)

http://cgi.ebay.com/INTEL-PENTIUM-4-641-650-651-660-HEATSINK-SKT-LGA775-NEW_W0QQitemZ350153104378QQcmdZViewItemQQptZLH_DefaultDomain_0?_trksid=p3286.m20.l1116

Thanks

Roxie2401

You cannot use a standard ATX heatsink, The 8400 have proprietary heatsinks/fans and motherboard heatsink retention brackets. 

The only upgrade I've found that works is the one, I posted the link too.

It would seem that some the early model 8400 six pipe heatsinks had problems, causing the system case fan, to sound like a 747 taking off.

Bev.

Bev,

That makes sense.

Do you mind telling me what memory you have in your 8400?  The CUPZ program tells me I have PC2-4200 with a clock frequency of 266 - the Dell listing that came with the box says I have 533M.

When I check various sources for replacement memory, the memory calculator indicates I should get PC2-5300 that runs at 333MHz.  For example, Crucial is showing DDR2-667 for the Dell 8400 and that's what I was heading toward - getting four 1gb strips all identical.  (CT907824).

Am I ok on the clock speed?  Is 667 ok or do I want the 533?  (Even the Dell site is now showing 667.)  What does the DRAM frequency mean?

By the way, after taking the box over to Geek Squad and plugging it in, finding it booted just fine and returning it home, the 747 jet sound no longer occurs.  Now I wonder if bouncing around reseated the heatsink more firmly.  Its a quiet now as it was when it was new, in 2004.

Roxie2401

667 should be fine. 

Bev.