I'm using a P4 3200GHz, Socket 478, with 500mB (had to downgrade because of 2 other faulty 500mB memory stick). It's the third system in the house so upgrading is out of the question.
Now for surfing the web and watching shows, listening to music, playing a game in its ability its working just fine.
Problem is when the CPU usage is peaking at 100%, things starting to crash like Chrome showing the 'Aw Snap' screen, or any other program shuts down unexplained. Or if I've dared to use a video convertor for 5 minutes straight at 60% CPU usage it crashes too.
Now I'm asking, would downclocking the CPU help prevent that behavior at a reasonable good manner?
First check if the inside of your computer is dust free and if the cpu heat sink is clean, dust might be causing the system to overheat.
Could also try looking into upgrading your cpu heat sink if it came with the stock cooler.
Mind listing the other specs of your computer such as system model, manufacturer, etc? If the computer is from a manufacturer such as HP or Dell, more than likely you will be unable to modify the system clocks to down clock it.
Well its not very clean but the temp measured 4-5 seconds after the PC crashes is 70-72 C.
Intel Pentium 4 3.20GHz Prescott
System clock 200MHz
Socket 478 mPGA
Bios: American Megatrends P1.10
I've also installed back the 2 512MB Memroy chips at Dual (Speed 200MHz)
Try to clean the case and heat sink out as much as you can first then check the temps. If it is still high then I would start to look into how to improve airflow into your case and replace your socket 478 heat sink with another.
Grab some compressed air cans and take the case out into an open air environment and go to town. I wouldn't use a vacuum, I believe those can make static buildups.
Cannot find the fans recommended for P4 478 sockets, but these are pretty good too.