RAM Problem

I have purchased used Corsair DDR2 RAM from eBay.
The RAM is Corsair CM2*1024-6400G
2*1GB sticks.

I have installed the RAM is showing different speeds at different times.
I have changed my RAM frequency to 800mhz in BIOS.
But no improvement.
still my RAM runs at 200mhz .
I disabled amd cool&quite
but this doesn't improve the RAM speed.
One friend suggested that it is CPU fault,but i am not sure.
Why does this happen?

Your Ram is not running at 200 MHz its a dual channel Ram that means its running at 400 MHz also this is due to fact your that your CPU is running at low speed.My ram is also running at 200 MHz as my proccy is running at 1.0 GHZ i am using AMD power monitor that's why.Also u can OC ur proccy and make ur RAM run faster and also check how much max frequency ur board supports.

CPU speeds are not constant. e.g. a 2ghz procy can underclock itself to 1.6 to save power consumption when system is at low load. It automatically comes up to 2 when power is required. I think this is the speedstep effect.

RAM speeds are also tied to the cpu speed, so they will also vary a bit simultaneously. Its normal.

Use everest and keep a track of the fluctuating speeds to get a better idea of the same.

In the current architecture, the processor FSB can never be higher than the DRAM. Minimum FSB:DRAM ratio you can do is 1:1. Your final memory frequency would be twice the DRAM.
So, what processor are you on? What are the FSB and multiplier values? What motherboard are you on? Did you check if it supports Dual Channel at 800 Mhz?

I am running on
AMD Athlon 64 x2 4800+(Brisbane)
Gigabyte GA-MA78GM-S2H.
Previously i ram my pc with Kingston 2*1gb 667mhz.
But i never faced problem with them earlier.
I am aware that processor underclocks when the AMD cool&Quiet is enabled in BIOS.
now i disabled it and my processor is not underclocking.
But ram is not showing 800mhz.

the calculations are as per the following in amd :-

CPU_f = CPU Frequency
DRAM_f = DRAM Frequency
Memory_f = Memory Frquency

for DDR/DDR2/DDR3 memories, Memory Frequency = 2x DRAM Frequency
thus cpu will show 400MHz DRAM_f for memory rated at 800MHz Memory_f

now..
let
(int_hsv) Divider <--> Higher Integral Value of Memory Divider = D

relation is
D = CPU_f / DRAM_f

your processor 4800+ assuming to be running at ~2500MHz
and your 800MHz rated memory has 400MHz DRAM_f

so
D = 2500/400 = 6.25
thus its Higher_Integral_Value is 7

so
D = 7

new DRAM_f = CPU_f / D = 2500/7 = ~357MHz

so cpuz should output DRAM = ~357MHz for 800MHz memory..

in ur screenshots it looks ~313MHz ...which is DRAM calculated by use of 667MHz memory
check in bios if ur memory is set to 667MHz

also...
Cool n quiet mayb be disabled bt it still remains active if u have chosen so in windows power schemes...

select power scheme = high profile..

Now my RAM is fluctuating around 400mhz

my friend says 400mhz on CPU Z means 800mhz only.
some one plz confirm.

did you even read previous posts completely???

Thanks.
sorry i didn't understand ur previous post.
but now i did got it.

to make it simple yes, 400 mhz in cpuid means 800 mhz.

Thanks for all who helped me,especially madnav.
problem resolved.