Question About FSB and CPU
 

Say if I have an xp 1800+ that runs 1530mhz at 133FSBx2, if I get some pc2700 or 3200 RAMs and adjust the FSB to 166 or 200x2, would I then be overclocking the CPU?
Another question concerns socket 478 P4's. I seen some of them labled 400fsb and some 533fsb, do the 400fsb ones run on 100fsb aka pc100 RAMs and quad pump to 400FSB? same goes for the 533 ones.
One final question. It's stated that the moment you OC your CPU you lose whatever warranty on it, how exactly do they (the manufacture) know?
Thanks

Yes, upping the FSB is overclocking. FSB times multiplier = internal CPU clock speed.

P4s can be ran with SDram on some older boards, but ANY P4 will be strangled by it, as the ram could only run at 100/133. They are on a quad pumped FSB (400 = 100x4, 533 = 133x4, 800 = 200x4).

As far as the MFG knowing about ocing, I'm certain they have some kind of Die Scanner or something to that effect, although I hear alot of times they don't even check.

You could increase your FSB and lower your CPU multiplier, therego you'd be overclocking the FSB only.

youd still be running the cpu out of spec tho which still constitutes to voiding the warrenty.

The 400 Mhz FSB ones do run on a 100 Mhz FSB quad-pumped but they require faster memory than PC100. Specifically, PC400 RAM (a.k.a PC3200) would fit those P4 perfectly.

eh?

pc3200 is ment for 800mhz quad pumped p4's (200x4)

Hmm... please see if my math is right:
pc100 x 4 = 400FSB
pc133 x 4 = 532FSB
As for DDR RAMs, are they doubled and then quad pumped? I guess not... since:
pc2100 = 133 x 2 x 4 = 1064
But then if it's 133 x 4 it equals 533FSB, wouldn't that be the same as pc133?
:eyemove:

DDR ram is only double pumped. P4's quad pump their FSB's not the ram. PC133/100 is not DDR ram. THey are SDR ram and aren't DDR. I think older cheap P4 boards came with PC133/100 ram. So those ram will only run at their marked speed ratings.

SDR PC133 = 133 mhz
SDR PC100 = 100 mhz
DDR PC2100 = 133mhz x2 = 266 mhz
DDR PC2700 = 166mhz x2 = 333 mhz
DDR PC3200 = 200mhz x2 = 400 mhz

A friend of mines had an older P4 board with SDR ram PC133. Ran like crap most of the time because of the huge limitation of memory bandwidth that SDR ram has. Older Athlon systems also suffered the same penalty with SDR ram. It's like having a very larger highway packed full of cars, but a very small exit to small streets leading to your destination.

Dual-channel PC3200 is meant for the P4 Cs. Single-channel PC3200 (or dual-channel PC1600) is perfect for the P4 and P4 As. Of course they didn't exist back in the days of the P4 Willamette and Northwood A (thus RDRAM was the only memory type that provided enough bandwidth for the P4).

Single-channel PC3200 (or dual-channel PC1600) = 400 Mhz = 3.2 GB bandwidth = FSB of P4 A.
Dual-channel PC3200 = 800 Mhz = 6.4 GB bandwidth = FSB of P4 C.

Demigod, I don't know about VIA or SiS, but Intel chipsets won't let the RAM run at that speed if the FSB is, for example, 400MHz, even if paired with PC3200. Max DDR speed for an Intel chipset is 266 with a 400MHz FSB, 333 for 533, and 400 for 800. 533/800 FSB chips can run the ram at up to 2.66X FSB speed.

Of course, overclocking changes that. ;)

I was able to oc my cpu from 1.8ghz to 1.92ghz. The fsb was 133 first now it's 142. That's not a huge step but smth is smth :)

I just realized that I can change the multiplier in the bios almost however I want. What risks are there besides heat to overclocking? I mean, say if you can keep the temperatures low, say 40-50'C for on die sensors, are there occasions where the CPU and/or other components would just die when you run out of spec.?
My computer's temperature went from 69'C during summer to now 57'C autumn in the great state of Texas ;)

watch out for the voltage on your pci and agp components, (it depends on your mobo specs, some can block voltage on bus for those devices)

What should I watch out for :p? I'm really new at this.
BTW, my mobo is Epox EP-8K3A and everything else is in the sig.

Overclocking might somewhat diminish the life of your CPU but by the time it dies it will be ancient (unless you're really pushing the speed up high) :p. There's SNDS (Sudden Northwood (P4) Death Syndrome) but I don't really know anything about it other than they can randomly die from overclocking or something like that. Personally, I wouldn't overclock with temperatures up in that area.

As for what KanedA said, I haven't heard of AGP/PCI voltages changing when overclocking. What can happen with overclocking is that the AGP/PCI bus speed gets set higher than normal, the more you overclock the higher it goes. If it goes too high it can cause problems with AGP/PCI devices and I think data corruption on hard drives. For example, my friend is running a Pentium II 400 MHz at 333 MHz. His board is using the Intel 440EX chipset which is meant for Celerons (66 MHz FSB). The Pentium II's FSB is normally at 100 MHz and the multiplier is locked so we maxed out the FSB option in the BIOS (83 MHz). His PCI bus speed is now 41 MHz instead of 33 MHz. If your motherboard has an AGP/PCI lock then overclocking will not affect the AGP/PCI bus speeds. Programs such as SiSoftware Sandra show the PCI bus speed so you can use that to see if your motherboard has that feature.

that's what I was thinking about :innocent:

It'd be convenient if I can read your mind KanedA, then I won't need to ask anymore questions, hehe~
n_w95482, thanks a bunch for the elaboration. I'll try OC once I get a new heatsink and fan.