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First post, by deksar

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Hi everyone.

I installed two identical, same type, same size 2 ram slots (512 MB each) onto motherboard ASUS P5PE-VM that supports DDR dual channel mode.

However, the problem is during the POST, it appears the RAM running at 333Mhz. Is that normal?

Checked BIOS, but I couldn't find no Ram mhz setting.

Verified my motherboard's manual, my RAM modules (brand&model) are supported under "Qualified Vendors List"

Am I missing something here? Any clue?
Thank you!

Reply 1 of 4, by gen_angry

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You have a 533FSB CPU in there, it's likely set/running at some FSB:memory ratio like 5:4.

I'm not sure where in the BIOS that you can set it to something else, it'd be something like 'Front side bus:memory ratio'. Ideal setting is 1:1 but that would run your memory at 266. You could hunt down a 800FSB chip to run that there.

I'm not sure what FSB:memory ratio would be to run DDR400 with a 533FSB chip, maybe someone can chime in? 3:2?

Reply 2 of 4, by deksar

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Good points, gen_angry, thanks.

Never thought CPU's FSB would limit DDR's speed.

I can easily find a CPU with 800 Mhz FSB or even thinking to have Core 2 Duo E6700 2.66 Ghz 1066 Mhz FSB.

So in that case, would DDR run full speed (400 Mhz)?

Reply 3 of 4, by Nexxen

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Last edited by Nexxen on 2023-03-08, 21:36. Edited 1 time in total.

PC#1 Pentium 233 MMX - 98SE
PC#2 PIII-1Ghz - 98SE/W2K

Reply 4 of 4, by gen_angry

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deksar wrote on 2023-03-08, 17:12:
Good points, gen_angry, thanks. […]
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Good points, gen_angry, thanks.

Never thought CPU's FSB would limit DDR's speed.

I can easily find a CPU with 800 Mhz FSB or even thinking to have Core 2 Duo E6700 2.66 Ghz 1066 Mhz FSB.

So in that case, would DDR run full speed (400 Mhz)?

I couldn't tell you tbf, I don't know how it would work with a 266 base FSB chip - have never used a DDR1 LGA 775 board with a Core 2 chip before. Hopefully someone can chime in there.

I just know that a 800 FSB chip should do 1:1 as that's 200 base FSB quad pumped, so it matches.