Faster RAM than motherboard allows?

[apdlmike]

Hey guys,

I'm putting together a system and have a bit of a quandry on my hands. The person I'm putting it together for bought 512mb of DDR400 RAM, but the motherboard's maximum is DDR333. Will the motherboard realize this and just underclock the memory?

The motherboard Mach Speed P4X400DBP VIA Socket 478 Motherboard and is coupled with an Intel Celeron D 325 2.53Ghz. That has the 533FSB, I believe.

Thanks in advance!

 

[micker377]

Should work OK. Set it up to match the motherboard/CPU settings.

 

[apdlmike]

Good news! Just to make sure, which settings are you referring to, the CAS latency and such? This is a new system, so it will be booting for the first time with this memory. If that will not work, I could pull some DDR333 out of another machine, put it in the new machine, ensure the settings are correct, then power down and swap the 333 for the 400.

 

[micker377]

Sounds like a plan! I was just talking about the CPU and memory speed (166).

 

[paparazi]

micker377
I made that mistake the other day saying 166 for a 533fsb CPU and of course it's wrong it should be 133.
Quad pumped 4x133=533
DDR400 AKA PC3200 will work fine in most cases on a board only capable of supporting upto 533fsb CPU's, no need to do anything, just set motherboard front side bus jumpers to 133 if it has them.
Martin

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[cdogg]

paparazi,
I think Micker377 was implying that it's OK for the memory bus to run at 166MHz (166x2=333).

apdlmike,
As long as you don't purposely overclock the FSB, then you should be OK. As paparazi said, it needs to run at 133MHz which the CPU is dependent on. The memory bus ratio might initially be set at 1:1 which would cause your DDR333 to run at 266MHz at first. With the proper ratio adjustment, you should be able to get the RAM to run at the right speed. Many newer BIOS's do this automatically for you.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
[tab][tab]- Aristotle
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[m33sta]

If you put faster RAM than the motherboard allows all that will happen is the motherboard will clock down. If you want it run at 400mhz you will need to increase the FSB of the proccesor to 800mhz and if its a P4 chip I believe Intel lock the FSB

 

[cdogg]

m33sta,

What? First of all, you've only repeated what was already said, but then you throw the idea in about a locked FSB. That's not true. Intel locks the CPU multiplier. The FSB is controlled by the motherboard and can be adjusted on most current boards.

If you re-read this thread carefully, you'll see that the 400MHz and 800MHz numbers you came up with don't apply here.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
[tab][tab]- Aristotle
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884