morganism said:
How does a Pentium M Centrino compare with a P4 and Athlon 64
I've been looking at Pentium M 1.7 Ghz with 1/2Ghz of RAM
what would be a comparable spec P4 and Athlon 64 (ie. what speed P4 or Athlon 64 would a need to get to achieve the same performance)
Right - to get some perspective:
It may be obvious to those who've seen me post regularly, but I'm a bit of an AMD fanboy. In the desktop market, in terms of bang for buck, they've got Intel pretty much cornered and Intel are desperately throwing money at trying to find a solution after the P4 Prescott turned out to be a bit of a damp squib. Last I checked they're trying to re-work the Pentium-M (Centrino CPU) design for desktop use - no idea how successful they've been yet.
Having said that, AMD haven't got things quite right in the mobile zone yet, so I'd hold off for a while.
So - Pentium-M vs. Pentium 4-M. To get the terminology right, Centrino is actually a group of chips, whereas the P4 is a processor only. The Centrino chipset basically consists of the Pentium-M processor and the chipset to drive it (Intel 855 IIRC), which includes built-in wireless and other nice mobile shenanigans. If you want those features in a P4-M laptop, they either need to have a chipset which does the job (rare), or you'll have to buy a PCMCIA card to do it.
When it comes to actual performance, the Centrino Pentium-M proc was designed for mobile use from the ground up - which means lower power consumption, larger caches, and more accurate branch prediction than the P4. In English, that means that a lower clocked Pentium-M will best a higher-clocked P4, as well as sucking less juice to do so. Ironically, Intel's marketing has shot them in the foot there, because they spent so long hammering on about GHz that many don't realise that a 1.7GHz Pentium-M will handily spank a 2.2GHz P4, and will hold it's own against a 2.6GHz P4 as well.
To combat this, Intel came up with an equally incomprehensible numbering system - the top of the range Pentium M is the 755 (2GHz), followed by the 745 (1.8GHz), the 735 (1.7Ghz) and so on.
Get the highest spec you can afford, even if that means sacrificing wireless performance for a better processor. Also remember that as rule of thumb, Pentium-M's perform as well as a P4 clocked 1.5 times faster.
Hope that helps.
J.