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.
I've heard mixed reports about overclocking the c1 cpus. I think it's still the luck of the draw. Same for the 2.5a's. My 2.4b runs fine at 150 fsb on an older 645dx board. Overclocking success also depends on your mobo and chipset. The Intel 845pe boards have been overclocking very well up to 166 fsb on some cpus. The sis 648 run about the same range as my old 645dx, 150-158. For ddram values, it depends on your chipset and the ratios available. For example, when the cpu is set at 133 fsb, with the 4:5 ratio (on sis boards), your memory would be running at 166 (double pumped = 333). At the 3:5 ratio (cpu/memory) the speed would jump to about 221 (133/221 = 3:5). With excellent memory, such as corsair or winbond pc3200, you might be able to run the fsb up to 160 with the 4:5 ratio (160/200 = 4/5). At that setting, your memory would be running at 200 fsb (x2=400). I haven't used the 845pe boards yet, so I don't know what ratios (cpu/memory) are available. You might want to examine the mobo manual before buying to look at the bios settings. I download them off the manufacturer's website.