Please clarify R40 Pentium 4 2.0 Ghz vs Pent M 1.3 Ghz

[IamtherforeIthinkpad]

Ive seen some talk about the Pentium 4 being power hungry and that is evidently a negative, but
I see some R40's with Pentium M1.3 Ghz and Pentium4 2.0 Ghz.
Why the big difference in speed.
Are they rated differently ?
Or are they truly 1.3 vs 2.0 speed capabilities.
Please clarify how they rate these

If they are true speeds , why would IBM offer such a big difference in speeds.
Thanks gents.

[pianowizard]

Yes, they are rated differently. I believe the R40 uses Banias Pentium M, and 1.3GHz is equivalent to 1.5GHz Pentium 4. So the Pentium M models are still slower, but battery life is much better according to the Trwbook.

[underclocker]

According to the chart below, which I believe was copied from Intel's site when Pentium M's were current cpu's, shows that a 1.3GHz Pentium M performs similarly to a 1.7GHz Pentium 4 M.

http://www.upenn.edu/computing/provider ... vider.html

With each .1GHz increase, there is about a significant increase in performance, with a 1.6GHz Pentium M roughly equivalent in performance to a 2.3GHz Pentium 4 M.

However (!), this isn't the whole story! The Pentium M's do some tasks a lot faster due to the larger (1MB vs. 512KB) cache AND they run MUCH cooler and use MUCH LESS power, meaning battery life is MUCH longer.

The Pentium M based R40's are generally preferred over the Pentium 4 M based units - although for raw speed, a 2.4GHz R40 would be nice even though it might get rather toasty.

The two varieties have different systemboards - they are effectily different models that can share peripherals, like batteries, optical drives, etc. The Pentium M models are more like T4x or R5x cousins, the Pentium 4 M models are more like R32's.

[imzjustplayin]

According to the chart below, which I believe was copied from Intel's site when Pentium M's were current cpu's, shows that a 1.3GHz Pentium M performs similarly to a 1.7GHz Pentium 4 M.

http://www.upenn.edu/computing/provider ... vider.html

With each .1GHz increase, there is about a significant increase in performance, with a 1.6GHz Pentium M roughly equivalent in performance to a 2.3GHz Pentium 4 M.

However (!), this isn't the whole story! The Pentium M's do some tasks a lot faster due to the larger (1MB vs. 512KB) cache AND they run MUCH cooler and use MUCH LESS power, meaning battery life is MUCH longer.

The Pentium M based R40's are generally preferred over the Pentium 4 M based units - although for raw speed, a 2.4GHz R40 would be nice even though it might get rather toasty.

The two varieties have different systemboards - they are effectily different models that can share peripherals, like batteries, optical drives, etc. The Pentium M models are more like T4x or R5x cousins, the Pentium 4 M models are more like R32's.

Actually the formula for equivalent P4 performance (northwood that is) is 1.5* the clockspeed. So a 1.3ghz Pentium M would equal a 1.95 P4 northwood in performance.

[dr_st]

The 1.5* formula is somewhat accurate, but not always. My 1.8P-M is a tad slower than my 3.0GHz P4, and about twice as fast as my 1.8P4-M.