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What differences between processors ?

post #1 of 13
Thread Starter 
Ok, there are the G3, G4, rumored G5, and processors from the "other world" like Duron, Athlon, ...

What are the main differences between them ?

Is a 500MHz G4 really faster than a 500MHz G3 ? (forget about the bus speed and memory).

Can you guys describe the speed difference between various chip RUNNING AT THE SAME FREQUENCY ?

Mac mini 2.53 GHz, 4 GB, NVidia's 9400M.
13" MacBook Pro 2.66 GHz, 8 GB, NVidia's 320M.
OS X Snow Leopard 10.6.8

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Mac mini 2.53 GHz, 4 GB, NVidia's 9400M.
13" MacBook Pro 2.66 GHz, 8 GB, NVidia's 320M.
OS X Snow Leopard 10.6.8

Reply
post #2 of 13
Thread Starter 
I don't know if it's really making sense, but it can be interesting to describe the processors by giving them the same theoretical clock frequency, says 500MHz.

What speed differences for the various existing PPC chips, 601, 604, G3, G4, all running in some hypothetical computer with the same bus, same MacOS, same HD and memory ?

And what about the bus frequency ? A 500MHz G4 on some (hypothetical) 200MHz bus will perform how much, compared to the same chip on a 100MHz bus ?

Mac mini 2.53 GHz, 4 GB, NVidia's 9400M.
13" MacBook Pro 2.66 GHz, 8 GB, NVidia's 320M.
OS X Snow Leopard 10.6.8

Reply

Mac mini 2.53 GHz, 4 GB, NVidia's 9400M.
13" MacBook Pro 2.66 GHz, 8 GB, NVidia's 320M.
OS X Snow Leopard 10.6.8

Reply
post #3 of 13
Thread Starter 
O, by the way, I apologise if I sound like a total idiot ! <img src="graemlins/embarrassed.gif" border="0" alt="[Embarrassed]" />

Mac mini 2.53 GHz, 4 GB, NVidia's 9400M.
13" MacBook Pro 2.66 GHz, 8 GB, NVidia's 320M.
OS X Snow Leopard 10.6.8

Reply

Mac mini 2.53 GHz, 4 GB, NVidia's 9400M.
13" MacBook Pro 2.66 GHz, 8 GB, NVidia's 320M.
OS X Snow Leopard 10.6.8

Reply
post #4 of 13
[quote]Originally posted by Kali:
<strong>Ok, there are the G3, G4, rumored G5, and processors from the "other world" like Duron, Athlon, ...

What are the main differences between them ?

Is a 500MHz G4 really faster than a 500MHz G3 ? (forget about the bus speed and memory).

Can you guys describe the speed difference between various chip RUNNING AT THE SAME FREQUENCY ?</strong><hr></blockquote>


it's not an easy answer. but I'll be a bit general

G3 @ 500Mhz
G4 @ 500Mhz

The G4 has an improved FPU (Floating point (operation) unit) and the addition of ALTIVEC. Altivec is where the G4 sees its performance increase over the G3 and other processors at the same clockspeed. Altivec can be used to accelerate many things such as voice reconigtion and compression. a G4 @500Mhz running an altivec enabled app like photoshop or Final Cut Pro will cream a G3@500Mhz. Why? It's taking larger chunks of data and processing it in the altivec unit of the processor which the G3 lacks.

The pentium 3 has something similar to altivec called SSE but its not nearly as powerful. The Pentium 4 has SSE2 and it resembles altivec closer but again isn't as efficient and powerful.

running at the same speed the G4 would be a considerable distance ahead of all of em.

There are also other reasons like pipelines, caches, etc but it's too much for one thread
post #5 of 13
That was a helpful description, nut, thanks. While you're on a roll, could you explain how the system bus speed plays into this discussion. For instance, comparing a 100MHz system bus on a cube or iMac (with equivalent chip speeds) to a 133MHz G4 tower, to, PERHAPS, a 233 MHz tower in the near future. For someone doing photo editing in photoshop and some DVD authoring, which factor matters more?
post #6 of 13
[quote]Originally posted by AugustWest:
<strong>That was a helpful description, nut, thanks. While you're on a roll, could you explain how the system bus speed plays into this discussion. For instance, comparing a 100MHz system bus on a cube or iMac (with equivalent chip speeds) to a 133MHz G4 tower, to, PERHAPS, a 233 MHz tower in the near future. For someone doing photo editing in photoshop and some DVD authoring, which factor matters more?</strong><hr></blockquote>

Bus speed advantages depend on how fast the processor is.

So using the example above with all processors @500Mhz, a 100Mhz Bus would be all you needed to feed the processor. The bus is split into the system bus and the memory bus. Both are measurements of how quickly each bus talks to either the memory or the rest of the system and the processor.

When processor clockspeed increases like in a G4/667, then a 133Mhz bus is needed in order to feed it the data faster. This is likely a reason why Apple keeps the lowend Powerbook G4/550 on a 100Mhz bus. There probably wouldn't be much of a distance because there isn't much of a bottleneck.

Right now, Apple's G4 systems DO have bottlenecks. But primarily in altivec enhanced operations which the G4 does so fast that it outpaces the speed at which the bus can feed it data and read the data.

It's been said that as low as a dual/533 G4 has bottleneck problems with the 133Mhz bus.

If Apple upgraded the bus speed to 266Mhz a difference would be seen only in apps that are memory intensive. Photoshop would be one, but it wouldn't be close to an overall gain. It would just be noticeable in the few operations that were bottlenecked (the heavily altivec optimized ones probably).
post #7 of 13
[quote]Originally posted by applenut:
<strong>


When processor clockspeed increases like in a G4/667, then a 133Mhz bus is needed in order to feed it the data faster. This is likely a reason why Apple keeps the lowend Powerbook G4/550 on a 100Mhz bus. There probably wouldn't be much of a distance because there isn't much of a bottleneck.

</strong><hr></blockquote>

Another important thing to know is that the bus speed often dictates what speeds are available for the chip. A 100Mhz buss will usually feed processors in incriments of 50 while a bus like 133Mhz would feed a processor in incriments of 33Mhz. Now, this does not mean that busses can't be adjusted to otehr frequencies, but that gets a little tricky.

My point is that the lower TiPB runs on a lower bus not only because it's cheaper w/o cutting out performance, but also that the processor is a 450 and therefore better supported with a 100Mhz bus than a 133&lt;hz.
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post #8 of 13
My stupid guess of all Processors running at 500Mhz

FP_Operations (non SIMD)
1) Athlon
2) G4
3) 604e
4) G3
5) P3
6) P2
7) P4
8) 601e
9) P1
10) 603e

Remember, before you flame me that a P4, is obviously faster than a 604e, remember, I guessed these IF ALL processors were running at 500Mhz.

I couldn't honestly say about Integer processes. But Id imagine a similar lineup.

As for SIMD, A G4, wastes everything at 500MHZ.

Thoughts?
post #9 of 13
you must add that excepting the altivec stuff , the G4 7400 and 7410 are better at 500 mhz than the 7450.
Office run at the same speed under a G4 533 or a G4 733 (anyway it doesn't matter...) but photoshop is much better under the 733.
post #10 of 13
[quote]Originally posted by Kali:
<strong>Ok, there are the G3, G4, rumored G5, and processors from the "other world" like Duron, Athlon, ...

What are the main differences between them ?

Is a 500MHz G4 really faster than a 500MHz G3 ? (forget about the bus speed and memory).

Can you guys describe the speed difference between various chip RUNNING AT THE SAME FREQUENCY ?</strong><hr></blockquote>

The only time you can say a 500MHz G4 is faster than a 500MHz G3 is if you are using an Altivec program, which there are not many out there that take advantage.
post #11 of 13
[quote]Originally posted by kHack:
<strong>Altivec program, which there are not many out there that take advantage.</strong><hr></blockquote>

<img src="graemlins/lol.gif" border="0" alt="[Laughing]" />
post #12 of 13
[quote]Originally posted by kHack:
<strong>The only time you can say a 500MHz G4 is faster than a 500MHz G3 is if you are using an Altivec program</strong><hr></blockquote>

Actually, the 7400/7410 has better floating point unit and a generally improved design, so MHz for MHz it will perform 5%-10% better than a G3, AltiVec aside.

The 7450 and its siblings can be faster clock for clock than the 7410 if the apps they're running were compiled for them. If they're running an app optimized for the 7400 it'll be slower.
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post #13 of 13
[quote]Originally posted by kHack:
<strong>

The only time you can say a 500MHz G4 is faster than a 500MHz G3 is if you are using an Altivec program, which there are not many out there that take advantage.</strong><hr></blockquote>

this is the second time you have posted this (AFAIK) and its annoying because it is flat out wrong.

altivec is used in many many apps today. Hell its integrated in OS X. OS X runs noticeably better on a G4 of the same clock than a G3.

altivec is used in apps that CAN use it. No, Word is not going to be altivec optimized because it can't be (for the most part).

But nearly all digital media apps now have at least some altivec code.
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