Dose MS-7258 BIOS support FSB-800(400MHZ) DDR2 ?

Question

Hi
I use MS-7258 Neo-V motherboard with the latest BIOS version 3.9 (AWARD) and 4G DDR2 FSB-800(400MHz).
The BIOS only recognizes 3G of RAM.
Sometime ago I used CPU-Z program and found out  that the operating frequency of DRAM is only 266MHZ !!! 
The SPD of DRAM indicates support for 200-266-400 MHZ frequencies ,and motherboard manual specifies support for DRAM 400-533 MHZ ,
also in BIOS we can set the frequency of DRAM to one of 200-266-auto,
the question is that why when I set the BIOS to detect the frequency of DRAM automatically (auto option) ,it selects the lowest freqency to operate (instead of highest possible frequency) ?
Thanks
 

Answer 1

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Sometime ago I used CPU-Z program and found out  that the operating frequency of DRAM is only 266MHZ !!!
CPU-Z shows the real memory frequency.  DDR stands for "Double Data Rate" (two transactions per clock cycle), which means that 266 MHz effectively translates to DDR2-533.
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and motherboard manual specifies support for DRAM 400-533 MHZ
Yes:
DDR2-400 (real frequency = 200 MHz)
DDR2-533 (real frequency = 266 MHz)
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the question is that why when I set the BIOS to detect the frequency of DRAM automatically (auto option) ,it selects the lowest freqency to operate (instead of highest possible frequency) ?
It has selected DDR2-533 (266 MHz) because that is the highest clock speed the memory controller of the VIA Chipset natively supports.
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The SPD of DRAM indicates support for 200-266-400 MHZ frequencies
Even though you may have DDR2-800 (400 MHz) modules, that does not mean you can operate them @DDR2-800 (400 MHz) on a board that natively only supports DDR2-400 and DDR2-533 memory modules.