Guide to P4-M in desktop

I saw someone earlier asking about this.
Here is a list of the ones you want to buy. They are all D1 Northwoods.
SL6WY=2.5
SL6VC=2.4
SL6VB=2.2
SL6V9=2.0
SL6V8=1.9
SL6V7=1.8
If you want to save some $ buy the lower ones they will ALL defalt to 12x in a desktop mobo. The higher ones "might" OC higher then the lower ones. Remember i said might.
They should all OC the about same because P4-M's use the best part of the wafer. That lets them run at a lower Vcore of 1.3V stock and they are all D1.

How to MOD the CPU to WORK and force the 200fsb strap.
1> Remove the BSEL1 pin with a mechanical pencil. Carefully!
2> Set N/B Strap to PSB800 set 1:1 >make sure your mobo allows you to set N/BStrap
Google to find BSEL1.
Or try> http://will.dashwood.me.uk/images/pin_layout.png
>>>>>TAKE NOTE YOU ARE LOOKING AT THE TOP OF THE CPU<<<<<
It will defalt to 1.5V, if your mobo supports lower Vcore try to set it lower it will run cooler.
You should use a aftermarket heatsink. So you make sure you get good contact with the cpu die. P4-M's do not have a crush guard,so its nice for cooling.

I run my 2.4 with IC7-MAX3 OCZ PC4000 gold v1.1 @ 3.0 1000FSB 24/7. WC now, TEC cooling after droop mods.. My max i got to boot windows was 3.4 but with 5:4. I didnt do any test or play games just normal windows stuff, but stable.. It just let me know it could do 3.4. I have the DROOP problem. Soon to be fixed, then i should hit around 3.6 @1:1
The advantage is it uses the best part of the wafer. So you can say its the best P4 northwood there is and no crush guard for better cooling. And you can get them cheap on ebay.
Have fun........
Anyone willing to try this pin mod on a P4-A ? That means you can turn a P4-A into a P4-C 12x. As long as its a northwood. I think the BSEL1 pin has something to do with the way the cpu's fsb was set by intel and how the mobo reads it. I think it will work, i read about it one time....EDIT: I guess P4-A to P4-C will NOT work. Thank you Markku.

BSEL pin defines fsb..
so if you remove that pin from A chip, for example 2.4ghz, you'll have a chip which defaults to 4800MHz. and that's pretty bad because most mobos don't have a failsafe boot with 100mhz fsb anymore (i think only asus ones have..).
i have keychained one celeron because of that and almost killed another. thankfully i didnt rip leg entirely off second time
this mod is only useful with really low-multiplier mobiles (p4m or low-speed mobile celeron) for other memory dividers than 3:4.. IF your mobo doesn't have nb strap setting.and with 875 mobos, it enables PAT. supposedly if bsel is at 100mhz then PAT is inactive, regardless of nb strap setting in bios.

so - if you have 865 mobo and nb strap setting in bios - don't bother.

I dont quite understand why you would remove the pin if it only sets the FSB, since with an Abit IC-7 you can set your FSB manually.

Unless you were using an Intel brand mobo with no FSB adjustments or something?

Or does it control the multiplier and make it default to 12x if its not on there?

yeah, it really is only necessary for mobos that don't let you set your FSB. However, sometimes the BIOS will pick up the real CPU microcode and ignore the BSEL pins. In this case, you're sort of screwed as far as OCing (I've experienced this with Albatron and Asus mobos).

Another note: mobile celerons keep their multiplier (they don't default to 12x like P4-Ms do). They have 256k cache and the bump from 128 to 256 seems to make a lot of difference.

Another note: there seem to be some odd things happening with >3GHz mobile CPUs. I think these are based off of the prescott core. They do not seem to default to 12x multiplier. All software will show a higher multiplier, but performance seems to indicate that a 9x multiplier is used.

I thought you had to do the pin mod ,to make it actually run at 800FSB.
So are you saying if i buy a P4-A or P4-B just set to N/B strap 800 and it will work like a P4-C ?

no, the multipliers in a normal P4 A or B are set permanently. You can do the BSEL mod on mobile CPUs because they all default to 12x in desktop boards and they all overclock well. You could theoretically do this with any CPU (I've done it with PIII CPUs to force 133 FSB). However, if you tried to do this with a A or B and the BIOS detected a 200FSB, they probably wouldn't POST because it would be too much of an overclock with their higher multipliers.

/edit: also, C CPUs have HT which none of these CPUs have.