Ram Speeds Question

[Hugh_]

So how do I calculate what speed it is running at?

 

Thanks,

Hugh

[katoptrys]

It is usually twice what CPU-Z shows you (mine is running at the 3200MHz XMP profile and shows 1600)

[Aidanlockett1]

go into your bios and look at your ram it should tell you, its ddr3 my guess is 1866

[COUPER MILLAR]

DDR stands double data rate. the advertised ram speed is 2x the actual speed of the memory module.

https://en.wikipedia.org/wiki/DDR_SDRAM

[mariushm]

6 minutes ago, Hugh_ said:

So how do I calculate what speed it is running at?

 

Thanks,

Hugh

 

Your memory runs at 631.6 Mhz.  Because DDR3 transmits 2 bits on every Hz, it's common to advertise DDR3 memory as having twice the real frequency.  So basically, in your case your memory is running at 2 x 631.6 Mhz  = 1263.2 Mhz

 

The processor uses that 5:8 divider to "lock" the memory frequency to the FSB frequency, a frequency used by the processor to function. In your case, the FSB is (631.2 Mhz / 8 ) x 5  = 388 Mhz when it probably should be 400 Mhz.

 

The SPD tab will list several "profiles" or "presets", combinations of memory frequency + timings that the memory sticks support.  If you have a frequency higher than 631.6 Mhz there, write down the frequency and the parameters for that frequency (CL , tRCD, tRP, tRAS etc) and then you can go in BIOS and manually enter the frequency and those parameters and there's a high chance the memory will run at that higher frequency.

 

[Hugh_]

Thanks for the replies. 

It is 1 x 4gb 1333mhz and 1 x 2gb 1600mhz in a775 board which runs the memory at 1066 when not overclocked

[Hugh_]

Thanks mariushm ill have a go at that

[Hugh_]

Got a bit of a problem...

[-rascal-]

15 minutes ago, Hugh_ said:

Got a bit of a problem...

 

It depends on WHICH memory slot your RAM is installed in on your motherboard.

Check "Slot #2" and/or "Slot #3".

[Hugh_]

there are 2 slots and nothing is showing up on any of them

[mariushm]

Yeah, check slot #2 and slot #3

 

Also i think i made a tiny error when calculating your cpu FSB. 

It's a 5:8 ratio and your memory is 631.2 so the CPU fsb should actually be (631.2 / 8 ) x 5 = 394.5 Mhz FSB , not 388 Mhz.

 

later edit :

 

Check and see if Aida64 can retrieve some information (in the Motherboard > SPD section) : https://www.aida64.com/downloads

 

[Hugh_]

there is nothing in slot 2 and there is no slot 3

 

ok im starting to under stand now

my overclock is has the FSB at 395 at a x 8.5