BSEL Pin Mod for 166MHz fsb on i845 possible?

I have a HTPC system here at home. Currently it has a 1.2GHz tbred underclocked undervolted for living room quietness.

I also have a dell mobo without OC options(of course). It is sock 478 i845. I have a 2.4C/200MHz fsb CPU that I put in it and it boots no problems but it runs at 100MHz fsb instead of at least 533MHz and idealy it could run @ 166MHz if the multi was there for it.

Has anyone done anything like this?

Intel white sheets don't have any BSEL pin setting for 166MHz fsb but there is a setting that is reserved. Check the pick below. The BSEL pin mod overclock has been around since PII on BX mobo and slot socket.

hehe, yes an good question.. i'm thinking often about.. when working on threads like this..
but i have not try'et this concretely.
possibly the hidden funktion could be work.. but on any capable p4-board..?

The "reserved" mode I believe was for the 266 (1066 effective) bus processors.

Albuquerque said:

The "reserved" mode I believe was for the 266 (1066 effective) bus processors.

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Please if you make statements like this give a link.

Did they even plan on putting the sock478 to 1066MHz?

The move to 1066 on s478 was planned way earlier in the P4 process, but was later scrapped in favor of LGA775 at such speeds or higher. There were never any plans for a 166/677 FSB on s478, therefore it's unreasonable to assume the reserved mode is for such a speed.

I found this for the 1066MHz CPU's. If anything the 266MHz fsb has more in common with the 100MHz BSEL pin settings than the reserved settings.

Albuquerque said:

The move to 1066 on s478 was planned way earlier in the P4 process, but was later scrapped in favor of LGA775 at such speeds or higher. There were never any plans for a 166/677 FSB on s478, therefore it's unreasonable to assume the reserved mode is for such a speed.

Click to expand...

Yeah I know there were never plans for it made public. There were never plans also at the inception of sock 478 that they would goto 200MHz fsb, made public anyway.

So you are sying that if I set the BSEL pins on reserved it will try to boot at 266MHz fsb?

I know my ABIT IS7 mobo had multipliers(1/5) for 166MHz fsb. This is built into the chipset.

Also please could give some links to this. If it is this freash in your mind you must know where you read it. I am not saying you are FOS. I just want to see this cause I don't remember this. I only remembered talk of 166MHz fsb.

Chances are, if you hotwired the BSEL to that reserved setting, the board either wouldn't boot or would boot at one of the other speeds (100/133/200). It's not fresh in my mind, the difference is my mind holds onto these things like a steel bear trap. The 166FSB was never endorsed by Intel, they had no intention of ever using it.

If you want to prove something, just drop your wire in there and do it already. Tell us when you get back how it went.

This page shows a mod for 166Mhz fsb with Xeons.

http://www.ctechnet.com/hardware/Asus/PC-DL/xeon603_604_pin_mod.htm

They show the reserved being for 166MHz fsb.

I covered bsel0 to make it "HH" which was the reserved setting but now it is booting at 133MHz fsb. Well if it has hyperthreading now I will be happy anyway and it will make a nice replacement for my 1.2GHz tbred in right now. I am not sure if it will have HT in this mobo though.

Was there a mod to make HT work on non HT mobo's?