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Originally posted by gloco
If you ever come to NYC, check out JandR, their stores take up an entire block directly across the street from City Hall. |
I've been there many times, actually. I tend to go to NYC once a year (at least for the past four years). They're not the most knowledgeable Mac retailer, but at least they have them and try to sell them! Have they rebuilt/remodeled after 9/11? I know they were closed down for quite a while, right?
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| One question: why is the clockspeed so "behind" what we have with PC's? Is their a specific reason due to heating or something (being that the G4 processor has more cycles or something along those lines?). Or is it that the clockspeed on P4's and Athlon's are bloated? I wonder when it's going to get to the point where clockspeed's won't matter and other things will carry more weight, like Floating point calculations, etc etc. |
The Intel/Athlon chips don't have "bloated" clockspeeds. Clockspeed is simply a measure of how many cycles the CPU makes per second. So a clockspeed is entirely accurate -- for that processor.
As for why IBM/Motorola are having trouble increasing clock speeds, that's a good question
I don't even think they know LOL
Does clock speed really matter today? Yes and no. One big difference between the Motorola/IBM chips and the Intel/Athlon chips is that the Moto/IBM chips execute more instructions
per clock cycle. Part of it is that the Moto/IBM chips use Reduced Instruction Set Computing (RISC) which means they can "fit" more operations in the same "space" as Intel/Athlon chips (which are Complex ISC or CISC), and they can cache more operations. Part of it is just the architecture of the Gx chips vs. the Px chips (chip design, pipelines, caches, etc.). So when comparing the two, you really can't compare "clock" speeds (MHz vs. MHz).
In addition, each chip has it's own "specialty" instruction sets. For example, the G4 chips have what they call AltiVec -- a part of the chip that does certain things *very* fast, but applications must provide AltiVec code to take advantage of it. So an AltiVec-enhanced app (like Adobe Photoshop) will run MUCH faster on a G4 than it will on a much "faster" Intel/Athlon CPU. But Intel/Athlon chips have things that they do better if developers take advantage of the chips.
Finally, each chip has strengths and weaknesses. For example, the G3/G4 processors are much faster than Pentiums at integer calculations, while the Athlon chips are the kings of FPU processing (much faster than Intel chips, even).
I'm sure you've heard the whole "G4 is twice as fast as P4" argument. It's partially right, partially wrong. G4s running AltiVec code simply blow away any Intel/Athlon chips running similar apps for Windows -- an 833MHz G4 will wipe the floor with a 2GHz Pentium
for these apps. G4s running non-AltiVec code are still much faster than comparable
clockspeed Intel/Athlon chips; however, it's not really the "700Mhz G4 vs. 1.4GHz Pentium" that you often see in ads, and the fact that the Wintel chips have such higher clock speeds effectively negates much of this difference. On the flipside, for some types of code that are very "MHz-dependent" (i.e. they are dependent on the CPU making lots of repeated cycles), the Pentiums and Athlons are significantly faster than the G4s, simply because of the difference in clock speeds.
Basically, the G4 is a much more efficient chip that can do lots more each cycle than the Pentiums or Athlons, but sometimes the number of cycles is more important. If IBM/Motorola could increase the G4/G5/Gx clock speeds to be equivalent with the Wintel chips, the Pentiums and Athlons wouldn't stand a chance. But I wouldn't hold my breath waiting for that to happen
The above is all my "layman" version of things
If anyone wants to learn a lot more about chip archetecture and the like, the two sites I would highly recommend are arstechnica and MacKiDo:
http://www.arstechnica.com/
http://www.mackido.com/Hardware/
Arstechnica is Wintel-centric, while MacKiDo is more Mac-centric, but both are great sites dedicated to providing technical information on stuff like this. An informative comparison of the G4 and P4 chip architectures:
http://arstechnica.com/cpu/01q2/p4an...4andg4e-1.html
