what do people mean with divideR?

[DaRky4YoU]

im totally new to overclocking and want to overclock but the only thing i dont understand is a so called divider, how do i use it and where do i get it, or is it at my bios??


thx, also thx for all the help i already had i really appriciate it

 

[goliathvt]

Well I'll need more info in order to help you make use of the divider... specifically what are your system specs -- cpu, memory speed and brand, motherboard model, power supply brand and wattage, etc. Either way, the divider is something that is set in the BIOS, usually in the Advanced section. If you have an Asus board, it's in the JumperFree section, called DRAM Frequency. If you have an Abit board, it's in the Advanced section and is displayed according to ratio.


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Dividers Explained
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A divider refers to the ratio at which the memory runs with the Front Side Bus (FSB). To understand how dividers work, you'll need to understand some terminology.


DDR - Double Data Rate. Any DDR memory activates output on the rising and falling edge of the system clock. This effectively doubles the data that gets processed by the memory and gives us its name, DDR. For example, PC3200 DDR 400MHz memory modules are actually 400/2 = 200MHz.

Multiplier - Each CPU has a specific multiplier. On Intel chips multipliers cannot be changed. 2.4's have a multi of 12. 2.6's have x 13. 2.8's are x 14. 3.0's have a x 15 multiplier.

FSB - Front Side Bus. There's only one FSB on Intel boards, so everything has to run according to it. This is great if you're running everything at stock. For example, say you have a 2.4C P4 and PC3200 DDR memory (rated for 400MHz), both running at stock speeds. Your memory is running at 200MHz (but with DDR, it's 200MHz x 2 = 400MHz). Your CPU is also running at a 200MHz FSB. Remember that 2.4C's have a x 12 multiplier, so if you do the math: 200MHz FSB x 12 = 2,400MHz or 2.4GHz. Make sense?

In this case, you're using a 1:1 divider, and your memory is running in sync with your processor. In other words, both are running 200MHz:200MHz (a 1:1 ratio).

Since the multipliers are locked on Intel chips, the ONLY way to overclock is to raise the FSB. So what happens if you overclock and you bump your FSB up to 250MHz, making your 2.4C o/c to 3.0GHz? (250MHz x 12 = 3,000Mhz or 3.0GHz)

Because everything is all controlled by one FSB, this would mean that your RAM is now effectively running at 500MHz (250MHz x 2). Chances are, there's no way your PC3200 sticks could do this kind of speed. This is where dividers come in.

There are 3 dividers: 1:1 (400MHz), 5:4 (333MHz), and 3:2 (266MHz).

So using our 250MHz FSB example, to allow us to overclock our comp but keep our memory in spec, we can use a 5:4 divider. That would give us:

250MHz FSB x 12 = 3.0GHz. But for memory, using a 5:4 divider means we multiply memory speed by (4/5):

250MHz x 2 x (4/5) = 400MHz, thus keeping our memory within spec.

So, one more example, just to be thorough:

Say we have a really good 2.4C chip and proper cooling. We want to overclock our comp to a 300MHz FSB. In this case, we would need to use the 3:2 divider in order to keep our memory in spec. Here's the math:

300MHz FSB x 12 = 3.6GHz for our CPU.
300MHz x 2 x (2/3) = 400MHz, again keepin our memory within spec.

Hope that helps. Let me know if you have any more questions.

Goliath

 

[DaRky4YoU]

thx man thats very helpfull

 

[OBLIVIONLORD]

Are you highering memory timming by doing this?

Is there a drawback to doing this or is it not harming any performance at all but just slowing down the memory just to increase cpu speed?

 

[Jambaa]

Thanks goliathvt!