Pentium 4 3.2E + P4C800 = 14 multiplier!

[AdamK47]

That?s right! I'm surprised I haven't heard of this before. I found this thread and noticed that the multiplier on the P4 was actually changed. I had given up hope that something like this was even possible with a retail Intel CPU. I picked up a 3.2E and sure enough it worked. This was with the P4C800 Deluxe. All you have to do is flash the P4C800 to the 1015 BIOS using the Asus DOS flash utility, install the 3.2E, and power on to verify that the multiplier is at 14 in the BIOS. You can even use the latest BIOS for the board, which is 1017. If you use the Asus flash utility it will erase certain information and change the multiplier back to the default of 16. To get around that just place the ROM file on a floppy and rename it to P4C800.ROM. While the computer is in POST press Alt+F2. This will start the BIOS recovery and will automatically update the BIOS from the floppy disk.

After all that you're all set to overclock! I have mine running at an even 3.5GHz using a 250MHz bus while running the memory at 1/1. This is at default voltage which makes the Prescott run cooler. With the 2.8E I had before, it would take 1.5V and the stability was still questionable. Now with it running cooler and so stable I don't have to worry.


Here's a CPUID shot.

 

[Thor86]

Nice find. :beer:

 

[charloscarlies]

very nice indeed

 

[AdamK47]

It is very nice especially since the price of the 3.2E has gone down considerably. The Prescott performs great with high FSB and memory speeds.

 

[Acanthus]

very nice find!

 

[Mingon]

I posted something similar 2 weeks ago, my asus P4R800-v does the same thing. It was more of a problem with this board as it has no AGP/PCI lock.

 

[AdamK47]

Yeah, it seems like a lot of the boards out there that were made before the Prescott was released detect the multiplier wrong with older BIOS versions. Some think of it as a problem, I think of it as a blessing.

 

[THUGSROOK]

just goes to show that Intels lock is breakable, and will run.

 

[n7]

I found that thread very interesting...the guys there were hoping to figure out how to remove locks with a customized bios for all P4s...but i think they got stuck when they couldn't find a bios editor.
May or may not be possible what they were hoping to do, but it was an interesting read for sure

 

[waldi]

Your message on this forum has given me some hope!

I have the exact same configuration, except my ram stick are ocz dual channel gold. 512 MB X 2

Question:

I don't have a floppy drive and I could put it in temporarily, but I was wondering if this can be done using bios update utility in windows. That's what I have used to update my bios to
1017.

Do you have to take out the cpu to do this?
And what do you mean by "while your computer is in POST" ?, sorry but I'm a newbe!

Thanks for your help!

waldi

 

[cbehnken]

Originally posted by: n7
I found that thread very interesting...the guys there were hoping to figure out how to remove locks with a customized bios for all P4s...but i think they got stuck when they couldn't find a bios editor.
May or may not be possible what they were hoping to do, but it was an interesting read for sure

If they can't find a BIOS editor I would seriously question my own intelligence before I allowed them to build a custome bios flash for me....

 

[AristoV300]

BTW this only works with the c0 stepping, not the d0. Soon Asus is going to add this as an option in the bios like the LGA775 boards.

 

[waldi]

I tried it and it worked. I got the multiplier changed to X14 with 1018.004 beta bios using windows update utility (no need for a floppy drive ). I'm a happy man now running my 3.2e at 3.5 with 1000mhz bus, and my ocz pc4000 at 500mhz 1:1 ratio.

 

[fluxcored]

I have tried 2 different p4 3.2E 1mb 800mhz with 2 different s-spec and the following was my result. Motherboard was Asus P4C800-E Deluxe.

SL7E5 stepping D0: Asus P4C800-E Deluxe BIOS revision 1018 did not recognize the PRB-1 14x multiplier, and the "cpu free lock" feature was not available. No prior BIOS revisions from 1014-1018 including all beta revisions did anything to affect the results.

SL7B8 stepping C0: Asus P4C800-E Deluxe BIOS revision 1018 recognized the PRB-1 14x multiplier and the "cpu free lock" feature was available. The CPU POSTed at 2.8Ghz (14x multiplier).


Good Resources to aid in this effort-

Intel Processor Spec Finder: http://processorfinder.intel.c...he=ALL&PkgType=ALL

P4 socket 478 Datasheet with PRB-1 chip list (Table 26 in section 5): http://www.intel.com/design/pe.../datashts/30056102.pdf

P4 LGA 775 Datasheet with PRB-1 chip list (Table 5-1 and 5-1 in section 5): http://www.intel.com/design/pe.../datashts/30235102.pdf

Tom's Hardware Guide reference to the PRB: http://www.tomshardware.com/mo...rd/20040916/index.html

Tom's Hardware Guide detailed discussion of the PRB(a must read): http://www6.tomshardware.com/m...rd/20040810/index.html


FYI in case anyone is still confused as to what is happening with the 14x multiplier: The MSR_PLATFORM_BRV bit 18 aka PRB is an intentional feature of the P4 Prescott family, and not the result of a haxored BIOS (which BIOSes use it is another story). Supposedly, the purpose is to provide an underclock option in systems which might not be able to handle the thermal specifications of the power hungry, hot running high end Prescott chips (older 478 motherboards). The chip POSTs with a default 14x multiplier which is assumed to run the CPU within thermal limitations on any platform. Apparently this is to prevent systems which may not be able to handle the thermal specs from constantly triggering the PROCHOT (automatic, real time underclock) signal or the TEMPTRIP (automatic reboot) signal that is built in to the P4 CPU.

[edit]
The SL7B8 stepping C0 chip initially did not boot at 14x, but 16x. Although the "cpu free lock" feature was available inthe BIOS it had no effect. After testing the SL7E5 and then reinserting the SL7B8, the 14x multiplier was finally available. It was probably nothing more than operator error, but if your chip supports the 14x, and doesn't seem to want to behave, try flashng 1018 BIOS and then powering down and reseating the processor.
[/edit]

 

[AristoV300]

Yeah I tried the new 1018 BIOS for the P4c800-E with the "CPU Lock Free" option on my 3.2E D0 and the option is not available also... From what I have read it works on the C0 stepping prescotts and the 3.4E D0.

 

[fluxcored]

Maybe waldi, mingon, adamk47 you guys can list your s-spec numbers and stepping of your cpus also? Interesting to note that according to the spec finder there is only 1 C0 stepping 3.2E (SL7B8) and only 1 C0 stepping 3.4E (SL7B9)

 

[lookin4dlz]

I just found out that my P4P800-E Deluxe has a bios update to allow this. So, my question is if I get a 3.2E C-stepping how high of an overclock might I be able to get. Would a 14 x 270fsb = 3.78GHz be unreasonable to expect (depending on the vagaries of overclocking of course)?

 

[Mullzy]

Originally posted by: lookin4dlz
I just found out that my P4P800-E Deluxe has a bios update to allow this. So, my question is if I get a 3.2E C-stepping how high of an overclock might I be able to get. Would a 14 x 270fsb = 3.78GHz be unreasonable to expect (depending on the vagaries of overclocking of course)?

I don't think you can actually get your 3.2E running at a higher OC than your current maximum, but the lower multiplier will let you get to that max with a much higher FSB. The theory would be that the P4 E's perform better at a higher fsb/memory speed with the same CPU clock speed.

Anyone? Do I have that correct?

 

[ntrights]

Originally posted by: Mullzy

Originally posted by: lookin4dlz
I just found out that my P4P800-E Deluxe has a bios update to allow this. So, my question is if I get a 3.2E C-stepping how high of an overclock might I be able to get. Would a 14 x 270fsb = 3.78GHz be unreasonable to expect (depending on the vagaries of overclocking of course)?

I don't think you can actually get your 3.2E running at a higher OC than your current maximum, but the lower multiplier will let you get to that max with a much higher FSB. The theory would be that the P4 E's perform better at a higher fsb/memory speed with the same CPU clock speed.

Anyone? Do I have that correct?

Yes thats correct! at FSB260 there is significant difference in performance between northwood and prescott. The challenge is to actually keep the chip cool enough for 24/7 usage at 260+fsb. Air will not cut it for 24/7 usage (C0 chip) with a 260+ fsb