DRAM Frequency...Which is correct?

[StealthTools]

Does this sound right?

1.)
Divider: 1:1
FSB: 200MHz
= DRAM: 400?

Or does:

2.)
Divider 1:1
FSB: 200MHz
=DRAM: 200?

 

[Puddle Jumper]

The first one is right.

 

[StealthTools]

I have a guys program that led me to believe that #2 is correct.. I guess someone is Wrong..

 

[Puddle Jumper]

With a 1:1 ratio the speed of DDR2 ram is double the fsb.

 

[Prototype]

Yes thats correct. CPU FSB is divived by 4.

 

[zildjianchris]

The first one is correct. However if your ram wasn't running in dual channel, Id be inclined to say #2 is correct also. Although I don't completely agree with it, when you run your ram in dual channel, you 'effectively' double your dram speed.
Eg.

800Mhz ram in dual channel: 800/2 = 400Mhz
800Mhz ram not in dual channel: 800/4 = 200Mhz

Im pretty sure I'm right, but by all means if it isn't right can someone please say something.

Chris

 

[Wildside]

mine says CPU/7, 1:2 ratio.

 

[Puddle Jumper]

The first one is correct. However if your ram wasn't running in dual channel, Id be inclined to say #2 is correct also. Although I don't completely agree with it, when you run your ram in dual channel, you 'effectively' double your dram speed.
Eg.

800Mhz ram in dual channel: 800/2 = 400Mhz
800Mhz ram not in dual channel: 800/4 = 200Mhz

Im pretty sure I'm right, but by all means if it isn't right can someone please say something.

Chris

Don't you double the speed because its DDRx ie Double Data Rate?

 

[zmatt]

I would say #1 is correct, but it really depends on what speed you are looking at. DDR means double data rate, and the effective speed of DDR is always twice what it is really running at. have my mem and fsb at 1:1 and cpu-z lists them at the same speed, signifying that it is reading the "real" speed. The effective speed is twice that, or in my case 800mhz. I really need to up my mem, its running way under spec.

 

[BongWizard]

the first one represents FSB: DDR2... FSB: DRAM indicates the ratio of the FSB to the single sided RAM speed, but because DDR2 runs double sided, an FSB: DRAM ratio of 1:1 means that the the FSB is half of the effective RAM speed... therefore the second one is correct

but, had you changed the word "DRAM" in the first one to "DDR2" then it too would be correct

eg. an FSB of, let's say, 400MHz with a 5:6 divider (ie FSB to DRAM) would mean the DRAM frequency would be 480MHz. Assuming that this is DDR2 SDRAM, we the multiply by 2 to find the effective speed, which is, therefore, 960MHz.