# BIOS and Windows RAM Speed not matching



## Radhesh Bhoot (Nov 17, 2012)

Hello Friends,

MY Config
CPU - C2D E6750 2.66GHz
MB- Intel DG41W
RAM - Corsair 4GBx1 DDR3 1600MHz
OS - Windows 7 Ultimate 64Bit

I am facing a weird problem, i have recently changed my Motherboard and Ram as my old mb and ram was having certain issues.
The problem here i am facing is that i am not getting the full speed of RAM in Windows 7 i.e 1600Mhz and in bios it shows 1066mhz whereas in cpuz software shows 800mhz so which one is correct... and how to determine at what speed the ram is working other than CPUZ software...

After visiting the intel website i found that only 1066mhz is supported but still in cpuz it shows only 800mhz

BIOS reporting - 1066mhz
Windows 7 - CPUZ - 800mhz
Max RAM Speed - 1600Mhz

BIOS Screenshot -- 


RAM CPUZ Screenshot -- 

Motherboard CPUZ Screenshot --


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## Cilus (Nov 17, 2012)

They are okay. Click on the memory tag and you will find that the DRAM Frequency is 533 MHz. Actually there is a misconception about the Speed of DDR1/DDR2/DDR3 Ram speed. A 1600 MHz DDR3 Ram does not run at 1600 MHz but at half the speed, i.e. 800 MHz. DDR stands for *Double Data Rate* which means it can transfer twice the data in a single clock cycle than that of a SDR (Single Data Rate). So the effective speed of DDR Ram is actually *Original Speed X 2*. In case of yours, if you click on the Memory Tab of CPU-Z, you will find the Dram speed as 533 MHz, which means its effective speed is equivalent to 1066 MHz.

SPD is different thing, it shows the different settings or configurations on which your Ram can Ram, provided they're supported by the CPU and Motherboard. Those Profiles are known as XMP profile. Current Motherboards can directly read those values from the Ram and configure it to run at its maximum official speed.


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## topgear (Nov 18, 2012)

@ OP - you won't be able to run the memory modules at 1600 Mhz speed without OCing due to chipset limitation.


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## Radhesh Bhoot (Nov 18, 2012)

Okies so is there any scope that i can overclock it to 1600mhz or i would have to run on 1066mhz


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## topgear (Nov 19, 2012)

well - that depends on few things .. overclocking the ram modules will also OC the cpu but you can still run the cpu close to stock speeds by playing with FSB and Dram ratio - anyway, 1600 Mhz would be too much ambitious - so try to settle for 1333 Mhz ram speed.


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