In my bios the place where it says external CPU frequency... Is that my FSB? What exactly is that? Oh, and my CPU speed should be the multiplier (18X) times the external frequency (133) Right? Also, what do I do to get my external frequency above 160? ~Temporal~
The FSB on a pentium is 4x the cpu external frequency. so 133 x 4 = 533 mhz and you have a 2.4 GHZ so your multiplier is indeed 18 (18 * 133 = 2400 mhz) The FSB is the speed at which the cpu "talks" with the memory controller. However, I always mess up when I try to explain this (even to myself) so maybe someone can go into more details.
I'll reiterate what harrack said. The P4's FSB is (100,133,200) x 4. But the CPU speed is only that unmultiplied speed (100,133,200) x (multi). As for the overclocking, there are a few things you can do. You can adjust the FSB:Mem ratio so that the Memory would run slower than the FSB. It would be 133:100. The other thing you could do is buy some PC2700 or faster RAM and take out the PC2100. But I still would try changing the FSB:Mem ratio first as it's very possible you're hitting the limit of your CPU. You can try increasing the Vcore, but don't go past 1.7V. Beyond that and you take a big risk the P4 (this is a known issue---and it's not due to the heat!). If you're already at 1.65V, II would not go any higher.
YEah, and vCore, what exaclty is that? Is that the voltage it gets? Oh and makeing the FSB higher wouldn;t do anything right? Since my motherboard is a P4B533 a 533 FSB... Heh, I'm not sure I get it... ~Temporal~
The Vcore is the voltage the cpu gets. By increasing the FSB from 133 to let's say 166 (PC2700 Ram speed (166 * 2 = 333) your FAB would be 166 * 4 = 666 mhz, so yes it would do something. So providing your cpu could do 18 * 166 = 2988 mhz, it would be faster than 22.5 * 133 = roughly the same (not sure if it's even possible but it's just to illustrate that a gain in FSB gives better performance than a gain in rough speed.) However, at a certain point, you'll find yourself on the edge of your system's capabilities and you'll need to find that sweet spot between rough sped and FSB speed. For instance, my system tops out at either 225 * 10 or 220 * 10.5 , I chose the latter because the negligeable increase in FSB doesn't make up for the gain in rough speed (2250 mhz vs. 2310 mhz) The important thing to look at is your temps. It also has to be 100% stable because if it crashes, then what purpose does it serve ? Personnally I was very lucky with my ram since it's only DDR400 but it does way more than that.
About that FSB:Mem ratio, what exactly would that do if I were to put it on 3:4 (apparently you have to flip up switch 6 in DSW1 on my motherboard) and inversly what would be the effect of changing it to 4:3? Also, as you can see in my sig, I have since upgraded to PC2700 (Kingston) from PC2100. ~Temporal~
You'd run the memory faster, but that could also cap how high you're able to overclock. I'd run it 1:1. Every CPU is different, but I have my 2.4B on a 174MHz FSB. Of course, it helps that the board I'm using (Abit IS7-E) has a PCI/AGP lock like most i865/i875 boards do.
There's an article at http://www.ocarena.com/articles/ddr_ratio/ratio1.htm abt mem ratios and the different performance not much difference if u ask me, clockspeed seems more important
Thanks guys... scenar that article really helped! I guess I will just run at 1:1 then... heh ~Temporal~
