T40

[marco1]

Hi there,
I'm considering purchasing a T40 but I have concerns as to why the processor speeds have gone down in this model from the T30. Someone told me that the Intel Centrino chip is superior to the chips used in the T30's and thats why it is a faster computer despite the lower processing speeds?

Thanking you in advance

[FTC]

Well,

You were correctly informed. A centrino (Banias based) T40 running at 1.5GHz has approximately the same processing power of a P4 running at about 2.4Ghz. It runs at lower frequency, but it can take profit of the clock cycles better, i.e the IPC (instructions per clock) ratio is better.

[christopher_wolf]

FTC is right; in addition, here is a pretty good processor equivalency guide to go off of. The T30s used Pentium 4-M processors while the T40s used actual Pentium Ms (in the Banias chipset) to start with.

As you can see, faster processor speed is not a great concern when it comes to a direct increase in performance as there are many other factors that also affect the overall performance of the system.

[pianowizard]

FTC is right; in addition, here is a pretty good processor equivalency guide to go off of.

Christopher, thanks for that great site! I have been looking for one comparing the different CPU speeds for a long time. The only thing missing is comparison with Pentium III.

[marco1]

Forgive me if I'm wrong but according to the chart a 1.5Ghz PM runs the equivalent of a P4 @ 1.7Ghz. It's also equal to a celeron running at 2.4ghz

[pianowizard]

Forgive me if I'm wrong but according to the chart a 1.5Ghz PM runs the equivalent of a P4 @ 1.7Ghz. It's also equal to a celeron running at 2.4ghz

The T40 may have slower processors than the T30, but it's still a better model than the T30, e.g. Pentium M draws less power than Pentium 4-M, better graphics cards, USB2 instead of 1.1, lighter, etc.

[FTC]

Hi,

Well, I think that the posted link is useful, but the data is not correct. As I said, a Centrino Pentium M (Banias core) of 1.5Ghz is more or less equivalent to a 2.2-2.4 Pentium 4. As this comparison is not direct, but based on several tests, There could be some error so that for some tests you may see it being only equivalent to a 2.0 or as much as a 2.6Ghz P4, but no way 'only' equivalent to a P4 running at 1.7Ghz. In fact, the 1.5Ghz core that would be equivalent to a 1.7 P4 would be the P-M based on the Tualatin core, which is previous to the Banias one... unforunately those were only built for up to 1.4Ghz... and you had to overclock them to get to 1.5.

[anthean]

While Dothan was a reasonable improvement over Banias, I personally believe the "system shootout" charts underrate Banias. For a comparison of Banias, Dothan, and the P4, see Anandtech: http://www.anandtech.com/cpuchipsets/sh ... i=2129&p=7

Agree with most FTC has said, except:

the P-M based on the Tualatin core, which is previous to the Banias one

Strictly speaking, Tualatin is considered a P-III.

[marco1]

Seems to be a little distention within the ranks as to who does what faster....I think it's fair to say and from what I've read that centrino has some distinct improvements over P4M's such as size allowing for a thinner lighter notebook and power consumption. Whether processing speeds are that different remains a mystery. USB 2 and perhaps better graphics in the T40 are definate improvements to but to someone like me who is a layman out there this is all a bit to confusing. I'm going o get a T40 install identical ram as my T30 2.2ghz put them side by side and see for myself. If the T40 comes out on top well somebody will be getting a used T30 under the tree!

Merry Christmas to all