why does my ram say its 800mhz when its actually 1600mhz ?

[RobCherry]

so my ram is 1600mhz, its patriot black viper ram, i have 4x4gb sticks. but when i check programmes like cpu-z or speccy they show it running at around 803mhz?? but in my bios the ram is set to 1600mhz?
why is this?

 

[Eduello]

That's the way RAM speed is measured in dual channel mode: 2x800MHz=1600MHz.

 

[Adamw0611]

^yup. On a side note, if you ever look at gpu-z your vram speed will show up as 1/4 of its advertised speed, like nvidia is 7000mhz for most memory speed but it will say 1750ish mhz

 

[moeid97]

it's the DIMM and cpu-z only tells u single channel memory band with that is 800 mhz but u'er ram is dual channel so 800X2=1600

 

[Pinhedd]

so my ram is 1600mhz, its patriot black viper ram, i have 4x4gb sticks. but when i check programmes like cpu-z or speccy they show it running at around 803mhz?? but in my bios the ram is set to 1600mhz?
why is this?

It is actually 800Mhz. DDR memory transfers data on both the rising edge and the falling edge of the bus clock. There are three equally correct ways to market memory:

The bus clock frequency which in your case is 800Mhz

The module standard which in your case is DDR3-1600, or 1600 megabits per second per IO pin. This can also be expressed as 1600 megatransfers per second, or MT/s.

The bus bandwidth which in your case is PC3-12800 or 12,800 megabytes per second per DRAM bus (channel).

Many marketing departments like to make stuff up like "1600Mhz effective" which is just nonsense that drives us engineers crazy.

 

[RobCherry]

ahhhh i see, it seems so obvious now, thanks alot guys. massive help!

 

[moeid97]

Well pinhedd deserves to be selected for best solution as he know more than us! great work!

 

[Pinhedd]

Well pinhedd deserves to be selected for best solution as he know more than us! great work!

Dual-Channel would double the aggregate bus bandwidth, not the clock frequency. Eg, 2x PC3-12800 channels yields the 25.6 gigabytes per second that Intel advertises for their DDR3-1600 dual-channel microprocessors

 

[Adicuta77]

Yeah... in dual channel make sense 800@ x2 = 1600, but if you have triple channel ?

 

[Tradesman1]

Yeah... in dual channel make sense 800@ x2 = 1600, but if you have triple channel ?

Channels have nothing to do with it, 800 is true freq of the stick, DDR is DOUBLE data rate so the data rate is twice the freq. Dual, tri,m Quad channel is another thing all together. DRAM is a 64 bit device - when in dual channel mode the sticks are 'seen' as a single 128 bit device, triple sees it as 192 bit, and quad sees it as a 256bit device