Thinkpads Forum

Can someone help me understand a little about the Pentium 4 vs. the Pentium 4M? I've seen Thinkpads with P4's well over 2 GHz, but newer models have P4Ms with lower clock rates. Is this just to preserve battery life? Do the P4Ms have less computing "muscle," as their slower clock rates would imply?

Thanks!

The Pentium M is supposed to give you better power consumption and less heat. The Pentium 4 usually gives more power, but at the cost of cooling and energy. If you want to use your laptop away from home and you travel alot, go with the M, if you want desktop-like power and don't need to travel too much, go with the P4. It's a little more complex than this, but you at least get the jist of things.

leoblob wrote:Can someone help me understand a little about the Pentium 4 vs. the Pentium 4M? I've seen Thinkpads with P4's well over 2 GHz, but newer models have P4Ms with lower clock rates. Is this just to preserve battery life? Do the P4Ms have less computing "muscle," as their slower clock rates would imply?

I believe you're confusing three different processors here, not simply two. There are P4s which are primarily desktop processors, P4Ms which are similar to the desktop processors but modified for Mobile (laptop) service, and the new PentiumM processors which are completely new (*) mobile CPUs designed to give the longest runtime on battery, run cool and yet have similar (or better) performance to the P4 based processors they've replaced.

One upshot of all these changes is that you can no longer simply measure CPU speed as an indicator of relative horsepower. The 1.5GHz CPU in my T40 is similar in performance to a 2.2GHz P4.

See: http://www.intel.com/products/processor ... /index.htm for more about this.

(*) Yes, I know that PentiumMs are in fact built on the "old" PIIIM's basic architecture.

Regards,

James

Thanks for the info!

Intel made it even more fun than that....

"Mobile Pentium 4" go 2.4ghz beyond 3ghz, bus speeds up to 533mhz. (IBM G series)

"Mobile Pentium 4M" go 1.4? up to 2.6ghz, bus speed 400mhz. (T30, A31 and earlier R40's)
http://processorfinder.intel.com/script ... rocFam=826

Pentium M up to 2.1ghz, bus speeds 400mhz going up to 533mhz currently. (later R40's on, T40 on)

http://processorfinder.intel.com/scripts/default.asp

Stuff like this is why you should never give marketing the steering wheel of the company.