Which of these two is faster?

[ryanflucas]

Out of curiosity, which is faster processor-wise: a PowerMac G4 Dual 500Mhz, or a PowerMac G4 867Mhz? I would assume the Dual processor machine, but maybe I'm wrong. How do Mac's handle dual processors, does it just split the load or is it comparable in speed to a 1.0GHZ machine?

Is there a handy reference chart out on the net that lists all the various Mac processors in order of speed that's kept pretty updated?

~Ryan~

 

[Chundles]

"Faster" is such a bad term, for applications that are multi-processor aware, the Dual 500MHz would probably be faster, for apps that can only address one processor, the 867MHz one would be better.

It's all about the application's ability to handle processors.

 

[FragTek]

As Chundles said, for the G5 to be most effective it needs programs that have been programmed with multithreading enabled which allows the program to utilize 100% of both cores.

As far as the G4 goes, with it being a previous gen chip with a different architecture it's not as efficient as the G5 even at a higher speed. Therefor the dual G5 @ 500 may actually be faster in single threaded applications as well. I'm not 100% though. Doesn't the G5 execute more operations per clock cycle than the G4? It's like the difference between a P4 and a Core Duo. A Core Duo @ 2.16ghz is faster than a 3.5+ghz P4 due to how many operations it executes in a single clock cycle.

 

[Chundles]

As Chundles said, for the G5 to be most effective it needs programs that have been programmed with multithreading enabled which allows the program to utilize 100% of both cores.

As far as the G4 goes, with it being a previous gen chip with a different architecture it's not as efficient as the G5 even at a higher speed. Therefor the dual G5 @ 500 may actually be faster in single threaded applications as well. I'm not 100% though. Doesn't the G5 execute more operations per clock cycle than the G4? It's like the difference between a P4 and a Core Duo. A Core Duo @ 2.16ghz is faster than a 3.5+ghz P4 due to how many operations it executes in a single clock cycle.

Um, where does the OP talk about a G5?

He's comparing two old G4 PowerMacs.

 

[Mord]

the dual 500 is faster in 90% of cases, the 7400 G4 is a fair bit faster clock for clock than the 745x G4 (the G4e) that added with the fact it's a dual.

 

[FragTek]

Um, where does the OP talk about a G5?

He's comparing two old G4 PowerMacs.

Sorry I read it wrong... The G4 with a 5 directly after it tricked my brain

Seeing this now... The 867 is more than likely going to be your best bet all around as a dual 500 would only slightly perform better with a multi threaded application than the single @ 867. Other than that, the 867 is going to straight rape the 500 in the speed department.

 

[Makosuke]

Depends entirely on what you're doing.

If you are running one processor-intensive thing at a time, and it does not take advantage of multiple processors (say, many Photoshop operations, or most of what iMovie does), then the 867 will be much faster.

If you are doing something intensive that makes heavy use of both processors (say, 3D rendering) then the 2X500 will probably be a little faster. Remember, though, that even under IDEAL circumstances, you lose a portion of the available power when running processes that use multiple processors, so it's going to be close.

If you are doing several tasks at once--say, compressing a video while surfing the web or working in another app--then the 2X500 machine will feel much faster, since it'll be able to more efficiently spread the work between the processors. A modern OS can do this sort of switching on a single processor, of course, but it works better with two.

It's also worth remembering that, assuming you're talking about the machines I think you are, the 867MHz one has a faster system bus, significantly better default graphics card, and a different cacheing system (the DP500 uses L2 cache only, while the 867 has faster, smaller L2 and larger, slower L3), all of which can be relevant (particularly the graphics) depending on what you're doing.

How about some real-world benchmarks, albeit on older applications:

http://www.barefeats.com/pm01.html

...and indeed, in FileMaker Pro (only uses one processor) the 867 is much faster, while in CineBench (heavy multiprocessor) the dual 500 edges it out by about 10%.

The closest thing to a good reference you're going to find are benchmarks at BareFeats, and maybe MacWorld (not sure how much of their results are aviailable online). You're only going to get comparisons of machines of similar vintage, though.