ratio & bus clock settings

[ssahl]

I have a Pentium II 300Mhz CPU that I'm using.
I have the ratio (multiplier) set at 4.0 and
the bus speed is at 75Mhz. Next to the chipset
on the motherboard it says PIIX4 but can I
set the ratio to 3.0 and then the bus speed to
100Mhz? Will it still work or is it locked or
something.

[Hpro]

PIIX4

is the BUSMASTER CONTROLLER and has nothing to do with the clock...

[Cricket]

Hi ssahl,

I'm not 100% sure about the PII 300MHz, but most Intel CPU's are multipier locked and you can't change the ratio (you can move the jumper to 3.0, but the CPU is stuck at 4.0).

Cricket

[ssahl]

ok I missunderstud, or was incorrect with the terminoligy
but my question still remains, the jumper settings on the
motherboard that say "ration" with the settings 5.5/5.0/4.5/4.0/3.5/3.0...ect
and the bus clk with the settings 66/75/83/100/112Mhz
Right now I have them set at 4.0 and 75Mhz (which works)
Is that the only setting that the CPU will work at?
If I set it at 3.0 and 100Mhz would that be faster, better or even work?
Please help out with some info. I'm just a software guy.

[Cricket]

Hi ssahl,

You could try to bump up the FSB setting to 83MHz and see if your system boots up. Only problem with overclocking (besides the extra heat) is that some devices don't do well above stock system bus speeds and you may end up with corrupted data.

If this is your main system, I say leave it as it is. If this is a "play" or "learning" system, then try upping the FSB a little and see what happens.

I'm not an overclocker though, so you may want to wait around till someone who has overclocking experience comes by. They can give you better advice.

Cricket

[Hpro]

OK ssahl - to successfully get the Pll - up to 100 Mhz bus you need to modify the CPU first - indeed this is very easy and then you can get it up at least 50 - 80 Mhz more than it is designed for.. Otherwise it will not be acknowledged by the board..

As this is a slot one - remove the CPU form the board and lay it down the FAN of the CPU facing you.. the NOTCH of the CPU should be right from the middle of the CPU On the left side at the starting point of the CPU you will see a NUMBER A1 this refers to PIN one - now flip the CPU around and and you will see on the right side of the CPU's end B1 this means First Pin of the second or back side of the CPU - now count from there to the left to pin 21 or B21 - then use a small piece of SCOTCH TAPE and tape over this pin - inset the CPU into the slot and then you will see the CPU is acknowledged as a 100Mhz bus CPU - this pin 21 is the Frequncy check of all SLOT ONES - when High - original frequency when LOW (Taped so there is no contact to the board ) then the board senses it as a 100Mhz CPU - oh this also works for CPU's bus 100...
jsut in case you need this - will make some pictures of that..

[ssahl]

ok cool, is that like the "pencil" trick or something like that
that I have heard of before? I will take some pictures of it
when I get home. The bios (award) have a cpu temp readings on it
is that acurate? There is like 3 different ones too. The first one
(the one that reads the highest) is pretty much at 133F and after running
for 2-3 hours in my garage it didnt change much at all does that matter?
should I set the bios setting to shut cpu down if it gets to hot? If so
how hot should I let it get before I set it to shut down.

[Toaster]

Howdy,
One word of advice here, only one of the PII-300 CPUs will run at 100mhz FSB.
The CPU "step" is SL2w8. The common SL2HA and others often don't.
Some system boards have a jumper to "force" FSB settings to 100mhz and this is perferable to a direct mod of the CPU.
All PII/PIII CPUs have an auto detect feature which fixes the multiplier and FSB settings on start-up.
Hpro's trick "forces" the system board into thinking the CPU is a PII-450.
The "Nominal" settings for the CPU is 4.5X 66mhz.

[ssahl]

ok sorry it took so long to reply, but I let someone use one of my hard drives
and I only have the one (41GB IBM) left and it's running XP (X PU) and it would not let me post replies on this web site so I had download netscape yuk
I do have jumper settings on the motherboard
and I am running that PII at 4.0X and 75Mhz. However the CPU temp. was hanging
around 124 F and I dont care if the CPU frys but I didnt want to thrash the
motherboard. I did however because that PII just seemed a bit slow put in a
Celeron A 466Mhz CPU using a slot 1 to socket 370 adaptor card and the temp on
that doesnt get over 98 F unless I leave it on for at least 3 hours. The settings I used on that was 5.0X and 66Mhz bus just like the CPU was made for.
but since the temp is fairly low and I also have the adaptor card which has
jumper settings to make a cpu run at 1.8/1.9/2.0/2.1/2.2/auto V so I was thinking that it would be a better one to juice up. Please thoughts on giving
that CPU more power. The settings on the motherboard are 3.0/3.5....5.5
and the bus is 66/75/83/100/112Mhz could I leave the stepping (or whatever)
at 5 like the cpu is labled at and just run the bus at maybe 83Mhz? If the PII
that I have is supposed to be running at 66Mhz 4.5X and I have it at 4.0 75Mhz
that's probably why it got so hot. Any and all info is a help. Thanks guys.

[Toaster]

Howdy,
A temp range of 125 degrees is still quite safe, no problem there.
It is unlikely that you will damage the system board but it is possible.
All Intel CPUs overclock...period. To what degree is the question. The PII-300 in all stepps EXCLUDING the SL2W8 will run reliably at 83.x mhz FSB but the PCI/IDE clocks will be high enough that they may cause errors.
Some PII's will even permit a .5X multiplier change, but its not real common.
The common SL2HA PII runs well at 75mhz but often balks at 100mhz regardless of voltage. The cache chips used on other the the SL2W8 are slower and can't deal with a 100mhz bus for extended periods.
Safe temps are upto about 140 degrees, above this and better cooling might be in order. Increasing voltage plays a BIG part on running temps.