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Discussion Starter · #1 ·
After reading about terms like "Bus Speed", "Rated FSB", "Quad Data Rate", "Double Data Rate" and "DRAM Frequency" i decided that "FSB: DRAM" function in CPU-Z software does not mean anything. Let me prove you:

My intel CPU has 266Mhz "Bus Speed". With Intel's "Quad Data Rate" technology this "Bus Speed" is multiplied by 4 times and by doing this we reach 4x266=1066Mhz "Rated FSB". Now let's check the memory frequency. I have "2x2GB 1066Mhz" labelled memory sticks. They actually run at 533Mhz. But thanks to "Dual Data Rate" they are multiplied by two times and reach 1066Mhz "DRAM Frequency". So in the end we find that both CPU and RAM are running at the same frequencies:1066Mhz. Then why this damned CPU-Z says that my "FSB: DRAM" is not 1:1??? IT IS 1:1...

So the programmer doesn't know anything about Intel's "Quad Data Rate" technology and it can't calculate "FSB: DRAM" properly. And this situation is misleading most overclockers.
 

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1:1 is going off the bus speed 266 and the RAM is going off the 533mhz. If you ran 1:1 it would make your RAM run at 266(x2) along side the base bus speed of your CPU. The multipliers are internal to the CPU and RAM and have nothing to do with the divider between FSB/DRAM. Hope that made sense and cleared this issue up.

Example: My E8400 at 400x9(3600mhz) with 1:1 divider run my RAM at 400mhz or 800mhz DDR.

CPU-Z shows RAM speed b4 the DDR is applied.
 

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Discussion Starter · #3 ·
i think there's no connection between this issue and cpu multipliers. 400x9(3600mhz)

if you set options in bios accordingly to see that CPU-Z gives you "1:1", then your e8400 runs at 400x4=1600Mhz (rated fsb) and your RAM at 400mhz or 800Mhz DDR. So you waste half of your cpu front side bus bandwith for nothing just to see that CPU-Z says "1:1" which is actually trivial...

EDIT: Sorry for calculating errors.I fixed them now.
 

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Quote:


Originally Posted by Nautilus
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i think there's no connection between this issue and cpu multipliers. .

Correct, it's between FSB and RAM ratio

Quote:


Originally Posted by Nautilus
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for peak performance both cpu and ram must have same rated frequencies.that's why i said you lose half of your bandwith.

No, Intel processors usually perform better with higher FSB/RAM ratios (5:6, 4:5, 2:3, etc...)
 
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