The AthlonXP At 4.5 Watts

**almera** · 01-16-2005, 04:14 PM

I'm trying to find best combination for my PC and I'm really confused. Finally I decided to go with this combination:

nForce2 IGP + mcp-t chipset motherboard.
2 x 256 MB - DDR333 memory
AMD Sempron 2500+ CPU

I will do this to run CPU as Mobile:
http://www6.tomshardware.com/cpu/20041001/index.html

Have someone tried this with similar setup?

Which nForce2 IGP + mcp-t chipset motherboard is suitable for this trick?

And I'm trying to find an answer to this problem:
Chipset Register For Changing The Multiplier

To make all this happen, the motherboard BIOS must activate a few registers to provide the required functionality. If this is not the case, the system simply crashes at the very attempt.

Chipset Register Bit/Function
NVIDIA nForce2* F6, Bit 4
E7, Bit 4 Halt Disconnect
FID_Change Detect
VIA KT133A 55 Bit 2=1
VIA KT266, KT266A, KT333 95 Bit 2=1
VIA KT333CF, KT400, KT400A, KT600 D5 Bit 2=1
*only works on a few boards

Unfortunately, it is only possible to change the multiplier on a few motherboards. One of the fastest, the Asus A7N8X-E, crashed every time we tried.

**FyreDaug** · 01-17-2005, 04:47 PM

Hmm thats interesting, something I am looking at, as my xp3000 draws much much more power than my 800 duron did. Is there any other solutions to modify clock speeds by how much load is needed? If you put on a winamp vis, or do some video encoding it will crank it up, but if you are just playing music it can drop down to save power?

It would help me keep my car off when I dont need it running

EDIT: Software related I mean, nothing where we actually HAVE to mod the chip itself.

**EBFoxbat** · 01-17-2005, 09:17 PM

I didnt read the TH article, but new AMD CPUs, like the the Sempron cores, cannot be unlocked. Period, not by shorting pins, not by shorting bridges.

My Athlon XP2500, which is several months old, cannot be multiplier unlocked.

the XP2500 Mobile is by default multiplier unlocked. (This is hope a mobile computer...laptop... throttles the CPU speed) If you have a motherboard that allows you to change the multiplier as well as the FBS (most allow FSB, few alow multiplier) than you can underclock the CPU causing a dramatic drop in power input (and heat output)

Make sure you get a Mobile chip... forget the PR #... doesn't need to be a xp2500, could be an xp2100...just get a mobile and you will be fine as long as your motherboard supports multiplier changes.

**FyreDaug** · 01-17-2005, 09:56 PM

Too bad Ive got an xp3000 barton core I think

**haileris** · 01-18-2005, 03:48 AM

Originally Posted by EBFoxbat

Make sure you get a Mobile chip... forget the PR #... doesn't need to be a xp2500, could be an xp2100...just get a mobile and you will be fine as long as your motherboard supports multiplier changes.

Just to note that I don't believe you need a motherboard that supports multiplier changes if you do the wire trick

http://www.ocinside.de/go_e.html?/ht...md_pinmod.html

Cheers
D

**EBFoxbat** · 01-18-2005, 09:22 AM

Originally Posted by FyreDaug

Too bad Ive got an xp3000 barton core I think

I'd give the Barton a shot, it depends entirely on when it was physically manufactured.

Originally Posted by haileris

I don't believe you need a motherboard that supports multiplier changes if you do the wire trick

If your board doesn't support changing multipliers, the board will defailt to the lowest multiplier it supports (which you would have no say over) and the chip will run at something like 800 Mhz.... however slow that my be, it would certainly run cool.

Technically you can shot pins like crazy...but!... it's hard and doesn't always work. It is very fine work, but requires no soldering. You MUST make sure to properly seat the CPU in the ZIF or you run the risk of your HSF not fitting properly and overheating (which may not be a huge problem for underclocking)

This link shows the technique for wiring pins. It's not applicable to you, but the technique is the same... see haileris' link for the propper pins. I've never been to that site so I cannot attest to its accuracy.