1333 FSB Mod, Confirmed To Be Working By Me.

[cryptocat]

Would be so very interesting to see whether theres also a FSB 1066-Mod for the Prescott2M!

See the thing is, i have a 630 pretested @ 4.4GHz, but my Asus P5AD2-E (925XE, capable of 1066MHz FSB!) often does crash when i OC it to 266MHz...

How could you figure out which pins you'd have to mark to get a 1066FSB?

Because theres gotta be an Option for that, hence the 3.73XE with 266QDR.

EDIT:

I Found the specs in the Prescott 3.73XE Datasheet. Will give it a try

[MarlboroMan]

lets take a closer look what are we doing:

I've read the Intel's Core 2 Duo/Quad processor documentation to figure out what are those pins.

On page 49 of Core 2 Duo processor, we can see that we are making a simple jumper between G30 (BSEL2) <-> J30 (VCC)





On page 60, G30 means:
BSEL2 - POWER/OTHER -> Output


And on page 61, J30 means:
VCC - POWER/OTHER -> ?



So, on page 75, I've found that VCC is an Input:



And on page 69, we can se an explanation what is BSEL[2:0]


and it points to Table 17 (page 30) which is:

I can't see a possible combination to 333MHz, just 266MHz (Q/X/E6XXX) or 200MHz (E4XXX). Maybe just newer processors have it (?)


So, this mod is simply make a jumper between BSEL2, an output FSB frequency selector, and VCC which is a simple power pin.

[Ace-a-Rue]

OK!...here's my question to all the experts on this!

why can't i take my Q6600, which is a 266 FSB processor, and JUST isolate BSEL2 pad on the cpu so it does not make contact with the foot pad contact within the cpu socket to make it go from low to high...won't that do the same thing as taking it from BSEL2 to VCC?

right now, for 266 FSB base processor...BSEL1, BSEL2 and BSEL0 are all suppose to be low resistance ( i presume grounded)...SO...if all i have to do to convert to 333 FSB processor is take BSEL2 to high...if it is grounded now, i am presuming that; isolating BSEL2 pad from the corresponding cpu socket leg should take it to high...CORRECT or NOT!?

lets take a closer look what are we doing:

I've read the Intel's Core 2 Duo/Quad processor documentation to figure out what are those pins.

On page 49 of Core 2 Duo processor, we can see that we are making a simple jumper between G30 (BSEL2) <-> J30 (VCC)





On page 60, G30 means:
BSEL2 - POWER/OTHER -> Output


And on page 61, J30 means:
VCC - POWER/OTHER -> ?



So, on page 75, I've found that VCC is an Input:



And on page 69, we can se an explanation what is BSEL[2:0]


and it points to Table 17 (page 30) which is:

I can't see a possible combination to 333MHz, just 266MHz (Q/X/E6XXX) or 200MHz (E4XXX). Maybe just newer processors have it (?)


So, this mod is simply make a jumper between BSEL2, an output FSB frequency selector, and VCC which is a simple power pin.

reading Intel's Xeon 5100 Series Datasheet I've found that on page 19:

Basically, bsel is a set of flags defined on the cpu that the motherboard reads to know what fsb to set as default. Input is measured in terms of high or low resistance. Thus, in the traditional sense, to achieve a high resistance from something that's originally low, you can use white out or nail polish or tape to cover up a land. In the pga days, it's be nail polish to insulate or just yanking a pin.

To make a high resistance into one of low resistance, one can either link it to a bsel of low resistance, or link it to a ground (vss).

It looks like from this technique as posted by op, it's been determined that you can link up a bsel that's originally flagged as low to a vcc (power) to bring it to high. I'm still thinking of the phenomena behind this myself, but it looks like it'd essentially be causing a relative resistance as seen by the motherboard to be high and thus be the same as isolation of the land/pin.

[MarlboroMan]

its not gonna work. but you can try it, it won't kill your chip thou.

tip:
if you don't want to mod your cpu, you can mod your mobo!

[Ace-a-Rue]

its not gonna work. but you can try it, it won't kill your chip thou.

tip:
if you don't want to mod your cpu, you can mod your mobo!

what does the motherboard mod entail?

[Tutti-frutti]

I have tested the 200-->266 FSB mod for E4300 (posted on page 4). But on a Asus P5B Deluxe, it doesnt seem to work The mobo powers on and off all the time (like you changed some settings in bios).

I connected the following dots: