need HELP with p4 Overlocking

[incinerate]

Hello all,

Tommorow I'm about to buy a new system. I can't decide between the 2.53 and the 2.4B. Which offers better overclocking potential? The memory I'll be using is the generic Samsung ddr 333 sticks that are so widely availalbe. I can't afford expensive corsair ram so please dont' suggest it.

My second question is in regards to these new "C1" stepping cpus, and the A series p4's. I hear a lot of people saying that 2.5A can easily overclock to 3.3Ghz. This is where I'm confused. at 3.3Ghz one would be at 25x133. However with the 2.53, one would be at 19x133. So to get to 3 ghz, one would have to reach an fsb of approx 158fsb. It seems to me that 25x133 is much more feasible AND yields a higher overclock, so what's the point of buying a 2.53? I sorta read the problem is in the DDR Ram, however i'm not sure how it works. with a 2.5A at 25x100 what speed would ddr333 ram be running at? and what speed would it be running at, at 25x133? and how do i calculate this value? the problem is I do nto know how to calculate what bus speed ram runs at, at various fsb's. Sorry if this seems confusing.

Basically, the bottom line is i want a p4 cpu within the 2.4-2.5ghz range that offers the BEST overclockability considering: I will be using the stock cooling , and I will be using generic samsung ddr333 chips.

Thanks for the help guys
Alex

 

[Kartajan]

my 2.4b only gets to 2.59 with stock cooling and minimal increase in core voltage. (scared to cook my cpu)

I think I am running 144 (576)MHz bus (based off 133(533) native clock)

edit: figure 2.73Ghz for a 2.53 that gets a similar percentage of o/c

I belive the DDR clock is 2x native clock. (DDR266= 133x2, DDR 333= 166x2, etc...)
This makes a 2.53G (133*19)

 

[Viper96720]

The c1 steppings can overclock better. If you get a 2.53 you'll need to run the fsb at 158 to hit 3ghz. Depending on your motherboard they're dividers so that you can run the fsb fast. While still keeping the memory close to spec. Most have 1:1, 4:3, 3:4 and 4:5 dividers. Calculate the memory speed by taking the fsb speed divide by the first number and then multiply the second number. Multiply the result by two in order to get the ddr speed. For example if you ran the fsb at 150 the 1:1 would give you a memory speed of 300(150x2) 4:3 = 225 (112.5x2) 3:4=400(200x2). Another way is to take the second number of the ratio divide by the first multiplied by the fsb.

 

[Goi]

C1 steppings generally overclock better, but there's no guarantee. Some ae stuck below 2.8GHz, others can hit 3.3GHz and beyond. Personally my SL6EF 2.4B does 3.02GHz stable, but only at 1.7V and with a Swiftech MCX4000 HSF. If you're sticking to the retail intel HSF, you may not get as much mileage.