What speed is my RAM?

[David9799]

Is there a way to tell what speed my ram is runing at when i OC my E6600? I'm using CPU-Z and i'm guessing under the memory tab under frequenicy i take that and times it by 2?

 

[Corasik]

More or less yeah. DDR (1/2/3/4 etc) all transfer twice per clock cycles, so DDR memory running at 333mhz for example, would be considered DDR667 (Ok, 666, but that numbers never gonna show up in a god fearing society like America ).

 

[David9799]

When i do it that way though it comes up to the same thing my bios says. p5w dh.

 

[steve258]

It is correct, by default DDR Ram speed is always twice the speed of actual FSB, unless you run a mem divider.

 

[pcAnywhere]

And the reason is that the signal is transfered on the up and down "slopes" of the change from 0 to 1, and not when at 1 or on 0.

I'll get my coat..

 

[David9799]

It is correct, by default DDR Ram speed is always twice the speed of actual FSB, unless you run a mem divider.

How do i know if i am using a mem divider? I'm using a P5W DH with a E6000 OC to 3.10ghz RAM is PC2 6400

345x9 = 3105 dram frequency is set to 690Mhz in bios but like you said CPU-Z says it's 690 when you times it by 2.

 

[mcc49]

under the memory tab in CPUZ where it says FSB: DRAM, if it says 1:1 then you arent using a divider

 

[steve258]

The fact that it is 690 means it is not running a divider. to run a mem divider look for 3:2 (460Mhz) or 2:1 (345Mhz). But with a DDR2 800 kit you shouldn't have to use a divider until the fsb goes over 400Mhz.

 

[David9799]

Yeah CPU-Z says FSB DRAM 1:1 345.5Mhz isn't that slow for my RAM though?

I have seen people say they have had the ram i have up to 1000mhz.

 

[Corasik]

I very much doubt that anyone has managed to get CPU-Z to display 1000mhz memory speed. That would be DDR2 PC16000.

The highest enthusiasts memory ive seen so far is Kingstons PC9600, which runs at 600mhz (DDR 1200)

Even top end graphics cards with the best possible ram are still only clocking in with 900mhz memory (DDR, so they advertise it as 1800mhz).

 

[David9799]

I very much doubt that anyone has managed to get CPU-Z to display 1000mhz memory speed. That would be DDR2 PC16000.

The highest enthusiasts memory ive seen so far is Kingstons PC9600, which runs at 600mhz (DDR 1200)

Even top end graphics cards with the best possible ram are still only clocking in with 900mhz memory (DDR, so they advertise it as 1800mhz).

Okay im confused my RAM runs at 800Mhz right? so shouldn't CPU-Z show 400Mhz? It shows 345.5Mhz. When i've OCed to 3.1Ghz

 

[steve258]

Ram speed only increases with the FSB speed unless you manually set the divider in BIOS. so in your case it's 345mhz (DDR2 690).

At stock:
FSB266.66 x 9 = 2.4Ghz RAM: DDR2 533

Your current setting:
FSB345 x 9 = 3.1Ghz RAM: DDR2 690

 

[pcAnywhere]

Your RAM is going as fast as the FSB is needing it to run. If you increase the FSB then your RAM will work faster.

As said previously, if you get a 400 FSB then your 800 RAM will still be able to work at 1:1. Cheaper RAM (with slower speeds) would need to be run on a divider to still work.

 

[Corasik]

You might get away with using the 4:5 multiplier, which would be running your ram at 860mhz with your current overclock. Just depends how well your ram takes the overclock. While running at 690 your pretty much guaranteed that your ram wont cause any problems.

Many boards default to 667mhz for the memory when 800mhz ram is installed, either because they dont recognise the faster speed, or because a lot of 800mhz ram needs more volts to boot, and the pc needs to be able to get into bios the first time around to change the voltages, to it kinda picks a 'safer' speed for the default boot.

 

[David9799]

You might get away with using the 4:5 multiplier, which would be running your ram at 860mhz with your current overclock. Just depends how well your ram takes the overclock. While running at 690 your pretty much guaranteed that your ram wont cause any problems.

Many boards default to 667mhz for the memory when 800mhz ram is installed, either because they dont recognise the faster speed, or because a lot of 800mhz ram needs more volts to boot, and the pc needs to be able to get into bios the first time around to change the voltages, to it kinda picks a 'safer' speed for the default boot.

Thanks for all the info it clears things up a bit.

I was under the impression that if i bought 800Mhz ram thats what its always going to run at.....silly me

 

[pcAnywhere]

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