mojo1701 said:
Like "Pentium" or "Athelon"? Anyway, I think I might've meant "Celeron."
Well, Athelon is a misspelling
. It's Athlon.
"Pentium" is Intel's branding for their midrange/high-end desktop/notebook CPUs (they used to use Pentium for server CPUs, too, but they don't anymore; now it's Xeon). "Celeron" is Intel's branding for budget CPUs.
Athlon is AMD's branding for their midrange/high-end desktop/notebook CPUs (they used to use Athlon for server CPUs, too, but they don't anymore; now it's Opteron). "Duron" was AMD's old branding for budget CPUs. "Sempron" is AMD's new branding for budget CPUs.
"Centrino" is branding for a package including a CPU and some other things; it's not directly comprable to the others.
mojo1701 said:
Are clock speeds the same for different manufacturers or not?
Clock speeds are only relevant for comparing within the same family of CPUs. Because the Pentium 4, Pentium M, Athlon XP, and Athlon 64 have radically different architectures, comparing them at the same clock speed is all but impossible and provides no useful information. At the same clock speed, the fastest CPU is usually the Pentium M, followed by the Athlon 64, then the Athlon XP, then the Celeron M, then the Pentium 4, and then the normal Celeron. But Pentium 4s and Celerons are always clocked much faster than the others, and both Athlons and Athlon 64s are usually clocked faster than Pentium Ms and Celeron Ms.
AMD generally advertises 'model numbers' rather than clock speeds. An Athlon XP 2800+ actually is clocked at 2.1 GHz. But an Athlon 64 2800+ is clocked at 1.8 GHz -- and will be much faster than the Athlon XP in almost all cases. Despite what AMD likes to say about their model numbers, AMD's model numbers pretty much correspond to the clock speed of the Pentium 4 they wanted you to compare their CPU to at the time they launched it. Because Intel's made several architectual changes over the lifetime of the Pentium 4 (and because software makers started using more Pentium 4 optimizations), AMD's model numbers got pretty seriously out of sync with Pentium 4 clock speeds at the end of the Athlon XP line; there are many cases where a 2.6 GHz Pentium 4 is faster than an Athlon XP 3200+, all other things being equal.
Until very recently, Intel just used CPU name + clock speed; recently they've started adding model numbers which make even less sense than AMD's (ignore them, and use the actual clock speed to compare; see
http://www.techreport.com/cpu/ for a chart), though so far OEMs (Dell, IBM, and the like) are still showing the actual clock speed. But the Pentium 4, Pentium M, Celeron, and Celeron M perform very differently at the same clock speed. A 2 GHz Pentium M is roughtly comprable to a 3 GHz Pentium 4, while a 2.8 GHz Celeron* is roughly comprable to a 2 GHz Pentium 4.
* I haven't seen a good review of Celeron M notebooks, so I'm not providing a guestimate on their performance. Also, the new 'Celeron D' chips perform much better than the older Pentium 4-based Celerons; they're still considerably slower than a Pentium 4 at the same clock speed, but it's nowhere near the same degree.
mojo1701 said:
And what does it mean when RAM is "shared"?
It means that instead of having a dedicated video card with its own video memory, the computer has an "integrated" video card that uses part of its main memory as its video memory. This is not a good idea if you want to do anything where graphics performance matters (games, most image and video processing work), but if you're sticking to business apps and want to save money, it's a good idea.
