Benchmark Tests?

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Does anyone know of a site comparing the benchmark results of Macs and PCs? Almost everyone I know says that PCs are faster than Macs since they have "a higher GHz speed". I want to prove them wrong!
 
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meltbanana314

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You can't benchmark PCs and Macs - they are completely different architectures.

GHz speeds don't matter anyway.
 
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How then can you compare the speeds of Macs and PCs? Has someone compared the refresh rates of games, or compared the processing of tasks in Adobe or other programs?
 
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meltbanana314

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You really can't compare the speed of Macs and PCs accurately, because most programs and games are made for PC and then ported to the Mac. PC World (or was it PC Magazine?) did a benchmark between a G5 and an AMD64 machine - but the programs were heavily biased towards the AMD64 machine. Except for Photoshop, in which the G5 was 1-2 seconds behind the AMD64 in rendering times.

Anyone who claims that PCs are better because they are 'faster' doesn't know what they're talking about.
 
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With the very complex architectures today, it is very hard to do an apples to apples comparison because so much depends on software today. If you wrote a simple program to add numbers from 1 to a million, it's likely that the machine with the highest clock
rate would win. But a programer could use the Altivec unit to do the additions much,
much faster or a programmer could use the SSE2 units of Pentium 4 and Athlon64 units
to do the same thing. The Altivec unit has more registers but could a programmer keep
them all busy?

The Apple world appears to assume that application developers will do some Altivec
tuning of their applications and Apple is pretty supportive of using Vector instructions
in their Apple Develoer web pages. There is much less support on the Intel/AMD side
and far fewer programs are optimized using the vector instructions there. Programmer
support is so-so as Microsoft and the Gnu folks have different syntax for using
vector instructions so you don't have standardization similar to what Apple has (if
you only have one compiler, then there's a defacto standard).

One of those rating sites shows a PowerMac 1.8 (single) as being a bit slower than
the Athlon64 3200+. I have both machines and the Athlon64 is more than a little
faster than the PowerMac G5. But I have the Athlon64 pretty well tuned.

For the responsiveness of my usual desktop applications, though, the difference in speed doesn't really matter. It does on builds with PowerMac builds taking well over
an hour and Athlon64 builds taking about 40 minutes. But I consider those background
tasks so the time to completion doesn't really matter. Both machines do a very good
job of not letting long-running background tasks affect foreground task performance.

What I've heard from the science/engineering types that need to crunch a lot of single-precision floating point numbers is that you can't beat Altivec for that kind of application. The interesting thing is that the Pentium 4/Athlon 64 systems also support
double-precision floating point math in their vector processors while the PowerPC
only supports scalar double-precision math via f87. Pentium 4/Athlon 64 also supports
double-prevision in f87. But I think that most heavy-duty number crunching is done
in single-precision.

The Pentium 4 architecture seems to me to be better at handling applications that
work on bytes instead of words. Maybe that's a CISC vs RISC thing. I note that the
pixel scheme on the Mac tends to be four bytes while it tends to be three bytes on Windows. Four bytes lends iteself to better alignment and better use of vector instructions. To use vector instructions with three-byte pixels requires a lot of extra
shifting and masking. Vector instructions generally work with objects that are sized as
powers of two.

At any rate, I've done a lot of assembler programming in x86 and am now doing the same for PowerPC so I'm sure that my opinions on various things will change with
experience.
 
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Thud

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Talk about beating a dead horse....

All you need to know is this:

The powerPC architecture is magical, which makes a single 1.8GHz G5 chip faster than a 16-processor Xeon running at eleventy billion gigahertz.
 
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BurntSmore said:
Does anyone know of a site comparing the benchmark results of Macs and PCs? Almost everyone I know says that PCs are faster than Macs since they have "a higher GHz speed". I want to prove them wrong!

Just point them at the current top super-computer systems, at least 2 of the top ten are G5 systems one of which uses Apple hardware. NONE of the top ten use PC hardware.

(btw the G5 is better known as the PowerPC 970 which is the big brother to the Power4 architecture, by far the majority of super computers use the Power4 architecture as it has been around a while now. The AMD Opteron is just starting to appear on the charts and it is a blindingly good chip although not quite up to the 970 yet.)

Amen-Moses
 
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Thud said:
Talk about beating a dead horse....

All you need to know is this:

The powerPC architecture is magical, which makes a single 1.8GHz G5 chip faster than a 16-processor Xeon running at eleventy billion gigahertz.

That's a bit of an exaggeration but a 12-processor 970 system running at eleventy billion gigahertz would completely show up a similarly spec'd 16 processor Xeon one. :spook:

Amen-Moses
 
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mmoy said:
The Pentium 4 architecture seems to me to be better at handling applications that work on bytes instead of words. Maybe that's a CISC vs RISC thing.

A particular bug bear of mine, the current Pentium 4 architecture is RISC! When running legacy (read Windows) applications the RISC processor is actually emulating the older CISC instructions.

The Pentium has used a RISC core since about 1998 (i.e since the PIII).

Amen-Moses
 
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Amen-Moses said:
A particular bug bear of mine, the current Pentium 4 architecture is RISC! When running legacy (read Windows) applications the RISC processor is actually emulating the older CISC instructions.

The Pentium has used a RISC core since about 1998 (i.e since the PIII).

Amen-Moses

Yeah, I know. It has a bunch of registers in the background
that do a lot of work behind your back for you. But Intel and
AMD have done a pretty nice job at doing a lot of the little
byte and bit twiddling operations pretty fast.

In general, though, it's easier to talk about P4/K8 as CISC
vs RISC as most people won't know what you're talking
about if you say that P4/K8 is RISC.

A lot of good stuff came out of the demise of Alpha.
 
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mmoy said:
Yeah, I know. It has a bunch of registers in the background
that do a lot of work behind your back for you. But Intel and
AMD have done a pretty nice job at doing a lot of the little
byte and bit twiddling operations pretty fast.

In general, though, it's easier to talk about P4/K8 as CISC
vs RISC as most people won't know what you're talking
about if you say that P4/K8 is RISC.

A lot of good stuff came out of the demise of Alpha.

The StrongARM chip also contributed somewhat as Intel bought the chip fabrication plant from DEC and five minutes later announced that the new Pentium design (what Linux calls the 586 architecture) was to use an ultra small high density Risc core. Strangely enough that is exactly what the SA was!

The SA had some lovely superfast bit twiddling and condition flag testing in it's tiny instruction set. For example you can do:

BR1
A=A-1 (setting condition flags)
If A is 0 set A = 8 (don't set condition flags)
If A is 0 bit shift B right by 4 (set condition flags)
If B is not zero branch to BR1

in only 4 machine code instructions that execute at 1 instruction per cycle, leads to some **** fast (if highly unreadable!) code.

Way back in the early nineties I had a BASIC program which simulated a globular cluster, it would run in around 8 minutes on a 486 DX, the ARM3 based Archimedes I had at the time managed to run it in just under 3 minutes. A compiled version ran on the PC in around 4.5 minutes and a hand assembled version on the ARM3 in 1 minute.

When I bought my SA powered RiscPC I tried out the hand assembled version, it ran in 7 seconds, I then re-coded it taking advantage of the SA only features and got the final program down to 1.7 seconds.

In those days DEC were unsurpassed when it came to processor fabrication and I reckon a lot of the SA & Alpha design ended up in Intel offerings, especially the new 'M' range and the Xscale processors.

Amen-Moses
 
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Amen-Moses said:
In those days DEC were unsurpassed when it came to processor fabrication and I reckon a lot of the SA & Alpha design ended up in Intel offerings, especially the new 'M' range and the Xscale processors.
Amen-Moses

I was working there at the time and I think that the feeling from the inside
was the yields weren't that good. DEC had great technology and products
but no marketing. And then there was Chainsaw Bob. AMD and Intel have
picked up some nice pieces from Alpha. Other companies have picked up
good pieces from the remains of Digital.

The Alpha has been going through a slow death. I had an AlphaStation 400
in the mid-1990s (I used Jensons and whatever the 266 Mhz systems were
named). I think that we had a few prototypes around for porting too.

I haven't logged into an Alpha machine for a few months but they are still
good for timesharing and servers. History may be repeating itself with
HP heaving talented people over the side.
 

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