Centrino Processors vs. athlon 64 and p4m

Nope. It depends on the application. Pentium M's are efficient in encoding, I believe the 1.8 coefficient holds for that use only. I've seen the P-M -> P4-M efficiency multiplier ranging from anywhere of 1.35 to 1.9 in CPU tests. Generally, 1.5 or so could be used as an average value.

Yes, 1.5 is the general value because the 1.6GHz Pentium M usually compares to the 2.4GHz P4 in performance. Thus you can expect to see the 1.8GHz Dothan run like a 2.8GHz Pentium M. Now to get to your question about processors.

First lets talk about battery life (while doing casual things such as wordprocessing:
Pentium 4 (desktop version): usually expect 60-90 minutes
Mobile Pentium 4: expect around 2 hours.
Athlon 64: 3 hours
Pentium M (used in Centrino package): up to 5 hrs.

Performance:
of the three processors, the Athlon 64 shows the best performance. Coupled with AMD's hypertransport technology, the athlon64 can have up to a 1600mhz bus speed if the mobo supports it. Otherwise is runs with an 800mhz bus speed. Thus the athlon64 gives you a three hour battery life while a comparable P4 (with 800mhz fsb) would give you 1 hr. Although Pentium M gives you wonderful performance, it can't compare to the Athlon64 in performance.
Athlon64 will give you best performance with average battery life. If you get the Pentium M it can still handle any game out there especially with a M11 video card. Stay away from the P4. They aren't meant to be used in lappys. laptops are meant to be portable. P4's weigh ten pounds and have virtually no battery life to speak of.

"Thus you can expect to see the 1.8GHz Dothan run like a 2.8GHz Pentium M"

I would just love that!

you shouldnt directly compare the processer speeds and buses, because they work differently. 800 bus on the amd isnt the same thing as 800 bus on the p4. i beleive the p4 bus can go both directions while the amd only goes one.

I 100% agree with this!

1.6 is the general value for Athlon64 because the Athlon64 3000+ (2.0GHz) usually compares to the P4 3.2GHz in performance.

Price/performance should also be important I think, and for comparion the Pentium-M "Dothan" costs roughly 3 times as much as Mobile Athlon 64... Also AMD64 processors are more future proof because of the built-in 64-bit & NX-bit support

Can any one comment on the relative heat output of the different processors esp. AMD 64 vs Dothan as this has potential implications for fan noise.

Thanks

dothan will run cooler but I'm not sure how much. Go check out the emachines section of the forum and look for reviews on the M6805 or M6807 and see if they have any heat problems. I believe that the heat is very limited and that the emachines runs very cooly.

From Rincewind's review of the Mitac 8355... he said "I cannot stress enough how quiet this notebook is", and that was a DTR A64. Noise should not be a big issue.

its dead quiet...

however every 15 minutes a fan does kick on that you do notice

what in the world are u smoking an amd 64 is noisy!! i have a sger 4750 and the fans will not turn off I would recomend an centrino there is very little difference and nothing so far takes advantage of the 64 bit proccer!!!!!!
I recomend the 2ghz pentium m becuase its faster than a pentium 4 3.4ghz in gaming go look for your self! AND ITS WAY QUITER THAN AN AMD 82 WATT DTR VERSION. I would wait to they get it down to like 62 watt but too bad no company offers a 62 watt 3400+ amd 64.

so P4 is heavier then usual laptops?

i dont think he was trying to make a point at all...he was clearly asking a question...

Sasuke: from what ive seen most p4 and AMD64 based laptops are heavier than centrino laptops (im not to sure what u mean by "usual laptops") cos they are marketed as DTRs instead of portables so they generally wouldnt be carried around as much.

pb.

ohh i fell stupid sorry sasuke

np!!

Wow! More dead and gone threads !

P4 (and AMD64) requires more cooling than PM systems. So it would naturally be heavier and bigger to accomodate the cooling.

Not true for Mobile Athlon 64, since the Pentium-M "Dothan" actually runs noticably hotter during normal load.

what exactly makes you state that?

spastic: I ran a couple of benchmarks on the p-m banias 1.5 ghz and it was about equivalent to a 2.2-2.4 ghz p4. I found a multiplier of 1.6 to be a good measure of its performance, just a tad lower than the amd 64 3000+ (which I benchmarked against). I would definitely recommend the p-m if u have the money, as it is much more expensive than amd 64 laptops.

Just check these threads for the numbers:
http://notebookforums.com/showthread.php?t=38764
http://notebookforums.com/showthread.php?t=40283

Above 70C for Pentium M "Dothan" compared to well below 60C for Mobile Athlon 64...

interesting. Seems like the dothan is hotter than even a desktop p4. Which makes me wonder, since the p4 desktop is using more than 3 times as much power as the dothan. I have the banias, so I can't speak about the dothan, but my cpu doesn't get very hot when I game. Mobilemeter doesn't work for me though, so I can't exactly say what temp its putting out.