I have a RAM divider question

[CrazeD]

I think I feel pretty comfortable overclocking, except for the fact that I don't quite understand how RAM dividers work. I understand what they do and why you need them, but I'm not sure I follow how to set one up.

Under Advanced Chipset Features and then DRAM Configuration it says:
DRAM Clock - [auto]
Does this mean it will automatically detect the correct frequency to run my RAM if I up the FSB clock?

Example: If I put the FSB at 250MHz, will the RAM run at 250MHz or will it automatically decide what will be the correct amount?

If not, what do I change?

I have read multiple tutorials about this, but they really only tell me what they do, not how to do it.

 

[Nitestick]

auto would no doubt be 1:1 in other words is you run an FSB of 250mhz your ram will be 250mhz/DDR500. it all depends on what frequency you want to run. for instance if you used 9:10 at 250mhz your ram would run at 0.9xFSB so it would be 225mhz. if you tell us what frequency you would like your ram at and what frequency the FSB will be at we can help. or tell us what the ram is so we have an idea of how overclockable it is

 

[CrazeD]

It's Kingston PC3200, 1.5GB of it. I'd like it to stay at 200MHz if possible. For whatever reason, my FSB is 204MHz stock and it likes that, but I don't want to run my RAM very hard because it isn't mine and it isn't supposed to be overclocked.

But I don't get where to change the ratio. Is there actually an option that says RAM divider, or is the divider just something to base what frequency to put the RAM at? Like, if I turn down my RAM frequency to 190MHz, then put my FSB at 210MHz, my RAM would run at 200MHz again, right?

 

[Nitestick]

tell me what options are under "DRAM clock" and tell me what FSB you would like to hit and i can help you choose a divider (assuming "DRAM clock" is for dividers). dividers are just a ratio that the ram will run at compared to the FSB.

 

[CrazeD]

Well once I figure out how to setup the ratio, I can figure out what ratio to use. That's not where I'm stuck.

I don't really know what FSB speed I plan to hit, I'm just going to keep going until I no longer can.

So basically, if I set the FSB to 250MHz and the RAM to 150MHz then that would be a FSB:RAM ratio?

EDIT: The options under DRAM Clock are all the different RAM speeds. Like you can pick DDR333, DDR400, DDR500, etc. Is that what I want?

 

[Nitestick]

i have no idea. i'm not familiar with dividers like that but i think a good place to start would be setting it at DDR333 which should keep the RAM speed well within reason for a while.

 

[CrazeD]

Ok, I'll try that when I get bored and decide to overlock. Thanks.

 

[lazer_viking]

I'm kind of a novice too, and I understand what you're saying when you say "So basically, if I set the FSB to 250MHz and the RAM to 150MHz then that would be a FSB:RAM ratio?", but I'm pretty sure thats not correct.
In you BIOS there should be an option called DRAM or something similar (if it's not there, then you need to invest in a higher quality motherboard. thats the boat im in at the moment). That is a memory divider. If you set DRAM clock to 9:10 and your FSB to 130, then your RAM will run at 117MHz because (130*9)/10 = 117. Alternativly, under the same circumstances if you set DRAM to 3:5 (i dont know if this is an actual option, im just setting these up to help you understand it.) your RAM will run at 78MHz because (130*3)/5 = 78.
Also, like I said I'm a novice and I haven't actually experimented much with this (still waiting on my motherboard...) I'm probably wrong. Wait till' one of the smart guys comes by and corrects what I've said before you believe this.
Hope it helps!

 

[idiotec]

So basically, if I set the FSB to 250MHz and the RAM to 150MHz then that would be a FSB:RAM ratio?

Not exactly. Even though it is set as numbers like that it is still a ratio so if you set RAM to 150 it is:

150/200=.75
.75x250 = 188

So in this case if you set your FSB to 250 and set RAM to 150, your RAM would be running at 188.

The options under DRAM Clock are all the different RAM speeds. Like you can pick DDR333, DDR400, DDR500, etc. Is that what I want?

This is the same thing, the numbers are just it 'DDR' speeds, not Mhz speeds. So you say you have a DDR333 option. In that case it would be:

333/400 = .83
.83*250 = 208 or DDR416

Make sense?

 

[CrazeD]

Kind of.

So I'm safe if I set it to DDR333?