Boot problems with new CPU/motherboard

Hi folks,

I have a client running Win2K server.  His motherboard & CPU crashed a few weeks ago.  After replacing both of them, the system will now boot up and operate.  (I won't go into the issues I had with getting Win2K to recognize the IDE controller.)

But here's what's going on now:

The old CPU was an Athlon XP 1800+ with 512MB ram.  The new CPU is an Athlon XP 2600+, which required new, faster memory (also 512MB).  I have been finding that if I run the new CPU at 1533 MHz, and the memory at 333 MHz, I have no problem with the OS running.  However, when I go into the BIOS and increase the speed to 2300 MHz and the memory speed to 400 MHz (which is what it's rated for), I can't get the system past the blue screens.

I'm wondering: Is this some kind of built-in stupid security thing with Win2K thinking it's gotten moved to a new computer, or what?  Is there a way around this?  I just think it's a shame to have spent $120 more on a CPU that can only run at the lower speed.

Incidentally, I've tried running with the cache disabled, and it was ridiculously slow, so that's not an option.

Any help will be appreciated.


Charlie T.
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NickRyanConnect With a Mentor Commented:
On the subject of the memory, an important thing to look out for is that many motherboards are quite picky which make and model 400MHz memory modules they operate correctly with (333MHz isn't so picky these days). Check the ASUS website for the list of memory modules that are compatible. Back to one of the previous comments, often upgrading the BIOS can also improve memory compatibility.

Generally speaking you shouldn't get problems using Kingston memory but there are other brands that are just as reliable, so don't feel forced to buy Kingston memory.

As a last point, check the power rating of your PSU - as you've just upgraded to a new, faster and more powerhungy motherboard, CPU and memory combination it is possible that the power supply either isn't quite good enough quality or doesn't have enough power for full speed CPU running, memory access, hard disk access and whatever else your PC happens to be doung at the time. Once again, it's not just the rating of the power supply that's the issue, PSUs from different manufacturers that are the same rating often perform quite differently in practice. My personal preference is to use Antec power supplies but once again, there are others just as good.
Rob StoneCommented:
When you boot the pc up what does the POST screen say the CPU is when it's running on 1533Mhz?

2300MHz doesn't sound right for a XP2600 at all. Also, what model of XP2600 CPU do you have?  To me it sounds like the CPU is being overclocked and is falling over hence the BSOD. Also can you give the RAM details such as speed guessing DDR400, CAS Latency, and anything else that's on the RAM Sticker. What motherboard has the user got now?

This url shows the core cpu speeds of the AMD XP CPU's
not all amd chips are able to be overclocked over 100mhz, it is a random luck to get one that can be oced good.  you could try slowly increasing the clock speed, and the fsb and see how high you can go, till you get the bsod, it sounds like it is a processor error, because of the overclocking, since you disabled the cache it ran...was it oced when u disabled the cache....if so, you may need a new processor
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charlietouAuthor Commented:
Okay, my bad -- I thought the 2600's actual running speed was around 2300 MHz.  There is an intermediate step of 1917 MHz, which I have tried.  When I chose it in the BIOS, I was only given the option of matching RAM at 333 MHz, instead of the 400 MHz memory that is now in the box.  It was able to boot successfully, but it blue screened in the middle of simple disk access stuff so I don't think I can rely on that setting in a production environment.

I don't have the specifics on hand right now, but it's an ASUS motherboard able to run Durons and Athlons.
At 1533 MHz, the POST screen does show Athlon XP 2600+.

I guess the question becomes, Should I actually have 333 MHz memory coupled with the 1.9GHz speed, instead of the 400 MHz memory I have?

Charlie T.
Rob StoneCommented:
The 400MHz RAM will work fine (if its not faulty) running at 333MHz. If you have two modules, take one out to see if the BSOD continues, and visa versa.

Some motherboards allow the RAM FSB and CPU FSB to be on independant speeds, but most are linked together.

If you have an A7V8NX-X mobo you may want to look at BIOS updates as they aren't very reliable. In any case, a BIOS update might be worth a look if your getting hardware related problems.

ASUS boards do usually pickup the speed of the CPU automatically so if you reset the BIOS to defaults and let it pick it up again see what happens. Make sure the RAM settings in the BIOS are set to SPD as well and are not overclocked.

If its still BSOD then there is a problem somewhere, can you get the BSOD error and post it here?
charlietouAuthor Commented:
Hi, I think that's the model of the mobo -- I'll check it out, and thanks for the update tip.  
There's only one 512MB chip in the computer.  

The BSOD's have been varied -- some are IRQL_NOT_LESS_OR_EQUAL, some reference Ntoskrnl.exe, some reference ntfs.sys.  The OS itself, when the system drive was pulled and placed in a substitute box, is fully stable and above suspicion -- again, unless there's some sort of built-in checking mechanism in place to see if the hardware hasn't changed.  I kind of doubt it at this point, but I have to think that it's possible.

I'm getting a 333MHz RAM chip from my dealer to swap out the 400 MHz chip, so at the very least I'll be able to see whether the memory is or isn't the cause.

Charlie T.
charlietouAuthor Commented:

If you could be so kind as to help me figure out how to navigate Asus's website, I would be sincerely appreciative.  I can't find anyplace where it talks about DDR compatibility.  I can tell you that the two chips I've tried are both Elixir -- the first at 400Mhz, the second at 333Mhz.

I updated the BIOS last night, set the CPU speed in the BIOS to 1917 Mhz, and everything seemed fine -- until this morning, when I saw that it had crashed twice.  So I swapped the memory to the 333 Mhz, and tried again.  This time, it blue screened at 1917 Mhz before the logon screen.  Now I'm back to 1.5 Ghz and Auto detect on Ram speed and things appear to be stable.

As far as the power supply, I honestly don't have a lot of experience with different brands.  What's in here now is a Future Power, rated at 400W.  There's an IDE controller card with 4 drives plugged in, and the onboard IDE controller has a single CD-Rom drive.  The CD is almost never active, and two of the drives are set to mirroring.  I'll leave it to you guys who know more than I do if a 400W power supply is sufficient for the setup.  

Oh, one other thing I want to mention -- in the course of swapping out the drives into a temporary server, and back again (and out and back again :-\ ), the Add & Remove Hardware list (when hidden devices are visible) has many items that are listed multiple times.  Can that have a negative effect on anything, and should I make it a priority to clean up the list?

Thanks again for your help.  

Charlie T.
Yes... ASUS's website can be a bit messy at times!  In order to get the best information you should go to the global site (not your regional site) and go from there... As I don't know exactly what your motherboard is, I can't go any further other than to guess a model: For instance, if your motherboard is a A7N8X-X (the "A7V8NX-X" quoted above doesn't seem to exist), then the relevant page is:

At the bottom of this page is the list of memory sticks that are guaranteed to work with the motherboard. Another place to look is the crucial website, although they only suggest their own memory of course (

In this case however, I'd really suspect the power supply particularly as you've just admitted to running 4 drives on an additional PCI controller card. Here's a reasonable site to check what rating PSU you ought to have, these are:

The results are only approximate but if you don't have a good quality power supply (and from what I hear, "Future Power" is not a particularly good make of power supply) then you will have problems when your mains power input fluctuates.

Personally I'd recommend fitting a 400W or 450W Antec or Enermax power supply, these should be good quality power supplies and by over speccing them a bit you give yourself some headroom for when the input power fluctuates.
Rob StoneConnect With a Mentor Commented:
I agree with Nick on the PSU.

I wouldn't read into the RAM compatibility too much though. As long as its the same spec you don't need to buy specific manufacturers of RAM such as Samsung, Kingston, etc thats just some modules they have tested that work.  I've used very cheap RAM in the A7N8X-X board and its been fine.

I have seen power issues causing these symptoms before, and also a dodgy motherboard. I'd go for a new PSU first.
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