# Ram of 1600 Mhz showing 800 Mhz



## esudip (Sep 28, 2011)

*[SOLVED]Ram of 1600 Mhz showing 800 Mhz*

Hello All,

I just purchase Asus P8Z68-V motherboard Monday. I also brought G.Skill 8 Gb Ram F3-12800CL9D-8GBSR2 which is suitable for my board here is the link which shows that motherboard is qualified for this click here In BIOS the ram shows 1600 Mhz speed but in Windows 7 64 bit it show that Ram is of 800 Mhz. I used CPU-Z and berlac advisor for this. Please guide me what is wrong ???

One more think when I installed the memary the motherboard wont boot up so I pressed the MemOK! button and then the board boots up with message that the Memory is OK now !!


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## Cilus (Sep 28, 2011)

It is perfectly okay. Any kind of hardware like CPU, motherboard Northbirge, PCI-E bus don't achieve their speed by a single step. Normally there is a base clock and each of the components has their multiplier value. So the base clock speed X Multiplier value implies the speed at which the component is running.

In XMP-800 profile the ram runs at 800 MHz value with a multiplier value of 2. So the operating requency is 1600 MHz. CPU-Z shows the RAM speed but not the multiplier value. So don't worry, your ram is running @ 1600 MHz speed.


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## hannibal2469 (Sep 29, 2011)

@cilus 
i dont think the 800 to 1600 is due to multiplier 
it shows 800mhz because the modules are running at 800mhz
@op
now the modules say they are 1600mhz because of double data rate i.e on each clock cycle two data transfers occur that is why your ram or any other ram that you buy from any other manufacturer would say wxyz mhz but that that would be the data transfer rate and your cpu z would show u the actual clock speed 
in short there is nothing wrong with your computer or ram


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## asingh (Sep 29, 2011)

800 is correct and the 1600 is theoretical due to channeling happening both ways.


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## hannibal2469 (Sep 29, 2011)

@asingh 
i dont understood what you mean by channeling happening both ways could you explain


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## asingh (Sep 29, 2011)

Just read this.

DDR SDRAM - Wikipedia, the free encyclopedia


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## hannibal2469 (Sep 29, 2011)

i have read it before and am reading it now i dont think it has anything to do with channeling both ways(BTW still dont get what you mean by that )
what ddr is, is double pumping which is transferring data on both the rising ad falling edge of the clock
if u are talking about dual channel than that has nothing to do with what the specs on the ram module say


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## Cilus (Sep 29, 2011)

I think you've missed the following lines:-



> With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate of *(memory bus clock rate) × 2 (for dual rate)* × 64 (number of bits transferred) / 8 (number of bits/byte). Thus, with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s.



Since a DDR ram can tarnsfer ram in the positive ( 0 to 1) and negetive (1 to 0) edge of a cycle, it can theoretically transfer data twice as the speed of the original clock speed.
Look at the below diagram:-
*www.davescomputertips.com/wp-content/uploads/2011/08/ddr_memory.png


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## hannibal2469 (Sep 29, 2011)

missed lines????
that is exactly what i said
all i added was that i dont get what channeling has to do with it


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## asingh (Sep 29, 2011)

^^
I used the wrong word. Apologies.


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## esudip (Sep 30, 2011)

Thanks all for Sharing your valuable knowledge. I got it.

Thanks


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