Forcing a C2 to 100FSB

[jkersenbr]

Is there a pin or wiring trick that can be done to hard force a Coppermine Celeron to 100FSB? I have a cheapie OEM board that I'd like to overclock with but can't because there is no provision in BIOS or jumpers to set the FSB.

I remember the pin trick on slot celerons and wonder if there's a way to do it with coppermines.

 

[jkersenbr]

bump

 

[EKAtBzboyz]

i personally havnt heard of any
but it would be interesting if i manage to come across something

 

[MustangSVT]

hmmm if your motherboard doesnt have settings for 100mhz fsb neither in bios nor by jumper, what makes u think it even supports 100mhz fsb? for example, old emachine m/b does not have ANY fsb settings.

only thing i can think of was, if u use slocket, sometimes they have jumper settings.

good luck.

 

[jkersenbr]

It has an intel 810e chipest -- it will even do 133 fsb. I've run an P3 "eb" in it just to check. It was just intended to autodetect all the cpu settings.

And the slocket would be easy. One can do the classic pin trick to a slocket. The only problem -- it's a S370 mobo...

 

[Zap]

I'd also like to find this out. It was referenced in a thread at the Sudhian forums from another thread, but I couldn't find the post. There's GOT to be a way. Last night I was trying to find out how to do this because I was helping a friend with a Soyo P4 Dragon motherboard with the VIA P4X400 chipset. That board detects his 1.8A and allows 100-132FSB. I read a bunch of reviews on the board and ALL the reviewers used 533FSB chips, and the BIOS allowed 133-165FSB. No jumpers, no settings in BIOS. So, I read some Intel white papers (developer.intel.com) and found two pins that tell the motherboard what FSB to run at, BSEL0 and BSEL1, which map to the AD5 and AD6 pins. So, I'm looking at the pretty pins underneath the CPU and thinking, "okay, do I cut AD6 or do I wire wrap it to another pin?" I chickened out. There's GOT to be someone out there who had successfully done this. Hmmm... I recall Tomshardware having information on doing this to a slot Celeron by masking a pin. Perhaps... knowing the pin, can do a pinout to the same pin on a socket CPU and break off that pin... then my friend can run his Celeron 366@550 in his Shuttle SV24! Still won't do any good for that P4...

I'm gonna investigate it and report back.

 

[jkersenbr]

Yeah, I had thought of that but am not skilled or brave enough to map pins out and cross-reference slot to socket.

On slot celerons, pin B21 is the one to insulate to force 100fsb. Works on slockets too. Maybe someone with the technical knowledge could trace down the circuitry on a switching slocket and see what needs to be done to the pins on a cpu to force bus speeds....

 

[Killrose]

The pin trick for C2's is actually to force it into a higher default core voltage. In other words from the STD. default (and I might be wrong here, been a long time since I did this to my C2 533 and my girlfreinds C2 566) 1.5v to a default of 1.6, anyway's it's .10volt higher. This will give you a chance at a higher FSB overclock. Never heard of the auto detect for FSB speed thing.

You can find the info over at HardOCP, but instead of using a small dia. wire, use the defroster repair kit trick. Took me all of maybe 10min to perform, and you can actually scrape away any overage between the 3 vid pins you have to connect to do this.

 

[Zap]

Killrose, with the old slot processors there were some pins at one end to mask for voltage, and another pin towards the middle to mask for automatic 100MHz FSB detection. This second pin is what we want to trace to a socket processor. I kinda forgot about this from earlier today (well, still at work also) but I do intend to track this baby down and try it. I'll report back here later.

 

[Zap]

Alrighty, got sidetracked AGAIN, and came up with this:

Intel has been using pins to tell the motherboard what FSB to run at. Remembering one of Tom's articles from years ago:
http://www6.tomshardware.com/cpu/98q2/980514/index.html
he shows readers how to convince all BX chipset boards to treat a 66MHz FSB CPU as a 100MHz unit by covering the B21 pin, to change a "low" signal to "high." I believe this information can apply towards the modern day Pentium 4 processors.

The P4 CPU has two pins, BSEL1 and BSEL0, which have "low" and "high" settings. Both "low" tells the motherboard to run at 100MHz. BSEL0 at "high" gives 133MHz (H-L and H-H are "reserved"). Logically extrapolating from the article on slot 1 processors... if we change BSEL0 from "low" to "high" by covering or removing the corresponding pin AD6, then the motherboard will assume 133MHz FSB.

This information may be of value to anyone who is using a motherboard that doesn't let them tweak. What got me thinking about this was a Soyo P4 Dragon motherboard using the VIA P4X400 chipset. A friend of mine asked my help last night with this board that he just purchased. He had a P4 1.8A processor which ran at about 2.42 (134MHz FSB) on an 845D chipset board and decided to upgrade motherboards. This Soyo board allows for 100-165MHz FSB adjustments in BIOS. However, if a native 533MHz FSB CPU is put in the board, BIOS allows 133-165MHz. If a native 400MHz FSB CPU is put in the board, BIOS will allow only 100-132MHz speeds. I suspect there are other boards like this out there, including the nice new Intel boards, which officially support 533MHz FSB but won't let you choose it in BIOS or via jumper.

By removing this pin and doing the "wire trick" on the VID0-VID4 pins, a P4 could be overclocked on even an Intel brand motherboard!

Well, enough of being sidetracked, time to see how this applies towards socket 370 processors. I believe it would be the same information for any socket 370 - which is my hope since jkersenbr has a Coppermine Celeron but I don't. The only Celerons I have to work with are older non-Coppermine ones, like the 366 (what were they called again? Katmai or something?). If/once I find out this information I will actually try it out on one of these older CPUs.

"I'll be back..."

 

[Zap]

ALRIGHT, HERE IT IS

I just wasted time doing this for you guys instead of playing computer LAN games with 4 buddies of mine that's been hanging out here for the past three hours waiting for me, so I hope #1 you guys appreciate this and #2 this works properly.

INFORMATION FOR BOTH SOCKET 370 AND SOCKET 478

 

[jkersenbr]

Thanks Zap! Great illustrations and everything! I haven't tried it yet but will soon and will dig this post up and let everyone know if it works or not. Once verified this will be good info to take over to the Overclockers.com forums too.