Some of us still use T4X either due to sentiment or as a silent typewriter. I am using a T42 (15' XGA) for www programming using Eclipse (javascript, php) - and with 2GB of RAM it still gets the work done after 14 years in service. After I recently disassembled and cleaned up CPU cooler (second time since the purchase!), applied motor oil to fan sleeve bearing I decided to make it even more silent, using NHC to undervolt CPU.
Methods used to find stable voltages:
1. find lowest voltage that passes NHC test
2. test the voltage for stability in real life applications: running firefox, playing 15-20 mins of youtube videos (max 720p), using Eclipse, playing music (in my case every NHC "stable" voltage above multiplier of 6 required a 1-step-increase of voltage to run stable in all my applications)
Warning:
The voltages stipulated below are stable for my particular CPU and my particular motherboard. Please use these as a starting point for your tests rather than a ready answer.
My CPU is a Dothan 1.7 (fsb 400MHz), my motherboard is one with dedicated ATI GPU: Radeon 7500
Lowest stable voltages:
Model: T42, CPU: Dothan 1.7 (Pentium M 735), Motherboard specs: Radeon 7500 Multiplier Voltage 6 0.700 8 0.732 10 0.796 12 0.860 14 0.940 17 1.068Please share your undervolt settiings below, this might help some oldtimers silencing their T4Xs