The 440BX chipset has been one of the best and most long enduring motherboard chipsets to ever come out. It was released about 4 years ago and many people still use it today. The chipset is probably most noted for its stability and advanced-for-its-time memory performance. More than 2 years after its release, Intel released the i815 chipset as a replacement for BX, but the 815's memory performance still couldn't quite match the performance of the trusty old BX.
Up to now, the fastest CPU that can "officially" run in a BX motherboard would be a Coppermine Pentium III 1.1 GHz on a 100 MHz FSB. Intel purposely made the newer Pentium III's and Celerons based on the Tualatin core incompatible with the old BX and original i815 motherboards by changing some of the CPU's pin assignments and the voltage requirements.
This is too bad since the new Celerons based on the Tualatin core have 256K of L2 cache which is the same amount that Pentium III's have. Unlike earlier PIIIs/Celerons, the Tualatin CPU's support Vcore adjustments in 0.025V increments and the processor system bus operates at 1.25V.
For the BX, the Vcore adjustments in 0.025V is not really a problem since most newer BX boards allow 0.05V increments, which is really close enough. Furthermore, most newer BX boards support CPU core voltages down to 1.5V or lower while Tualatins use either 1.45V, 1.475V or 1.5V for the default voltage.
A bigger issue are the differences in the processor system busses. Pentium processors prior to Tualatin use AGTL+ which uses 1.5V signal levels. The newer Tualatins use AGTL with 1.25V signal levels.
If you want to read about the processor system bus further, please see page 11 of the Celeron datasheets which can be found here.
The specifications sheet for Tualatin Celerons state that AGTL and AGTL+ are incompatible. This may be true based on their design but in practice you CAN get the Tualatin CPU's that need AGTL signals to work with motherboards that provide AGTL+ signals. I don't know what the long term effects of running this out of spec would be so please do the modification that I will describe at your own risk. I have not heard of anyone killing their CPU by doing this but then again this modification hasn't been around very long. around for a couple of months.
Once again, try the modification at your own risk since you will be running your processor out of spec and could void your warranty. I accept no responsibility for any mishaps you might have. If you can't afford to lose it, don't use it.
Up to now, the fastest CPU that can "officially" run in a BX motherboard would be a Coppermine Pentium III 1.1 GHz on a 100 MHz FSB. Intel purposely made the newer Pentium III's and Celerons based on the Tualatin core incompatible with the old BX and original i815 motherboards by changing some of the CPU's pin assignments and the voltage requirements.
This is too bad since the new Celerons based on the Tualatin core have 256K of L2 cache which is the same amount that Pentium III's have. Unlike earlier PIIIs/Celerons, the Tualatin CPU's support Vcore adjustments in 0.025V increments and the processor system bus operates at 1.25V.
For the BX, the Vcore adjustments in 0.025V is not really a problem since most newer BX boards allow 0.05V increments, which is really close enough. Furthermore, most newer BX boards support CPU core voltages down to 1.5V or lower while Tualatins use either 1.45V, 1.475V or 1.5V for the default voltage.
A bigger issue are the differences in the processor system busses. Pentium processors prior to Tualatin use AGTL+ which uses 1.5V signal levels. The newer Tualatins use AGTL with 1.25V signal levels.
If you want to read about the processor system bus further, please see page 11 of the Celeron datasheets which can be found here.
The specifications sheet for Tualatin Celerons state that AGTL and AGTL+ are incompatible. This may be true based on their design but in practice you CAN get the Tualatin CPU's that need AGTL signals to work with motherboards that provide AGTL+ signals. I don't know what the long term effects of running this out of spec would be so please do the modification that I will describe at your own risk. I have not heard of anyone killing their CPU by doing this but then again this modification hasn't been around very long. around for a couple of months.
Once again, try the modification at your own risk since you will be running your processor out of spec and could void your warranty. I accept no responsibility for any mishaps you might have. If you can't afford to lose it, don't use it.
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