LCD iMac Benchmarks

[arn]

Barefeats posted benchmarks comparing the G4/733, Dual G4/800 and LCD iMac 800.

The older G4/733 has the advantage of a 133Mhz bus vs the iMacs 100Mhz bus... and this appears to make a significant difference. The Dual 800 does quite well.

 

[Xapplimatic]

Fair comparison? Maybe...

It's not exactly fair to pit a new iMac against a Power Mac when the PowerMacs compared all have system buss speeds 33% higher.. Then again, the iMac to a comparably equipped G4 PowerMac is about 33% less in price and has a more ergonomicly adjustable screen.. trade offs.. trade offs...

Hopefully Apple will get smart and offer their small and medium sized LCD flat panels for Power Macs on stands which do the same trick as the iMac positioning wise. Can't they just take a new iMac case or an old cube, add a few pounds of heavy metal inside to keep it weighted, and attach their PowerMac LCD screens to the neck? That'd be pretty sweet!

 

[moby1]

Yes but what if you DO need the SuperDrive

Looks like the iMac is pretty comparable to the 733 exept for gamers.

The SuperDrive really makes the iMac a great value for those of us who want to start archiving data on DVD's as opposed to having to sort through a dozen CD's everytime to find something.

Plus, don't tell me the new iMac won't start a whole new wave in DVD ripping!

- time for me to go check shipping status on my iMac order...(again)

 

[abe]

I'd like to see how fast the 933 is ...

 

[Luk3]

iMac G4 w/o altiVec?????

theimac.com wrote:


The new iMac gains the PowerPC G4, which the PowerMac has had for 2-3 years now. Running at 700 and 800Mhz, the new iMac gains a lot of the speed of the present PowerMac, which has a maximum speed of 867Mhz. The PowerMac will still have a slight speed advantage in some applications, and in many Velocity Engine enhanced applications like Media Cleaner, and the like.


Does it means, that there is no AltiVec engine in iMac v2 G4

 

[Stike]

22 Frames p/s in UT ??? Is this a joke?
I must believe that game must have some crappy code!

 

[scar_ace]

Re: iMac G4 w/o altiVec?????

Originally posted by Luk3
theimac.com wrote:


The new iMac gains the PowerPC G4, which the PowerMac has had for 2-3 years now. Running at 700 and 800Mhz, the new iMac gains a lot of the speed of the present PowerMac, which has a maximum speed of 867Mhz. The PowerMac will still have a slight speed advantage in some applications, and in many Velocity Engine enhanced applications like Media Cleaner, and the like.


Does it means, that there is no AltiVec engine in iMac v2 G4

Please tell me this isn't true is it?? I'm getting a bit doubtfull of my soon to be new imac.

 

[irmongoose]

Why dont you look at the official Apple site for once???

It clearly states the velocity engine........ the barefeats people must have meant that the Powermac takes more advantage of it... i dont know... but the alti-vec engine IS in the iMac, that much is obvious



irmongoose

 

[abe]

I also doubt that the Quake3 framerates are correct.

Does Quake3 support 2 processors??? I always thought that games do not support more than 1 processor ...

 

[arn]

Originally posted by abe
I also doubt that the Quake3 framerates are correct.

Does Quake3 support 2 processors??? I always thought that games do not support more than 1 processor ...

Quake 3 does support 2 processors.

arn

 

[gandalf55]

its all bus speed... which includes all of those Ghz machines out there... you could come out with a 300Ghz chip, but with a 133Mhz or 100Mhz board, whats the difference gonna truly be?

 

[IndyGopher]

Originally posted by irmongoose
Why dont you look at the official Apple site for once???

It clearly states the velocity engine........ the barefeats people must have meant that the Powermac takes more advantage of it... i dont know... but the alti-vec engine IS in the iMac, that much is obvious

irmongoose

Or perhaps, upon reading that official Apple site you mentioned, you'd come to the conclusion that the absence of L3 cache in the iMac is what they counted on for making the difference. Just a thought.

 

[tywoods@mac.com]

imac

boooooomm!!!

 

[Sayer]

Uhm, actually

Its the Cache stupid. The new iMac lacks any Level 3 cache at all. The G4 towers tested do.

Believe it or not the CPU runs off the cache above and beyond main memory the vast majority of the time. Only as a last resort is main memory accessed because it is in fact so slow compared to the cache. The memory controller also pre-fetches data that the CPU may need next so its right there ready to go in the really fast cache (level 2 or 3).

The new iMac only has 256k on-chip cache. The old G4 towers had Level 3 cache up to 2 meg. There's your performance boost source.

All this whining about bus speed is silly, there is not a direct 33% performance increase in a 133 MHz bus vs 100 MHz. Either get a clue or get off this ranting about crap you are not familliar with.

 

[blakespot]

Re: Uhm, actually

Originally posted by Sayer
Its the Cache stupid. The new iMac lacks any Level 3 cache at all. The G4 towers tested do.

...

The new iMac only has 256k on-chip cache. The old G4 towers had Level 3 cache up to 2 meg. There's your performance boost source.

All this whining about bus speed is silly, there is not a direct 33% performance increase in a 133 MHz bus vs 100 MHz. Either get a clue or get off this ranting about crap you are not familliar with.

I'm afriad not--the G4 733 in this test also lacks an L3 cache. The pre-Quicksilver G4 733 tower (old, graphite case) was the only 733 to sport an L3 cache (as it was the top-end model before the Quicksilvers came out).

The low-end Quicksilver (both in those released this past summer and the ones released a few days ago) has always lacked L3 cache.

(But you do provide generally sound advice at the very end...)


blakespot

 

[Unregistered]

Re: Re: iMac G4 w/o altiVec?????

Originally posted by scar_ace


Please tell me this isn't true is it?? I'm getting a bit doubtfull of my soon to be new imac.

This isnt true. Get your son that iMac of prepare to be handed a guilt trip from hell.

AltiVec is the signature feature of the PowerPC G4. They do have a version without it however, and its called the PowerPC G3.

 

[blakespot]

Originally posted by abe
I also doubt that the Quake3 framerates are correct.

Does Quake3 support 2 processors??? I always thought that games do not support more than 1 processor ...

Indeed, Quake 3 supports dual processors directly. Another game that does is Giants: Citizen Kabuto done by OmniGroup (though the PC original does not). Both of these games run like lightning on my dual G4 800 + GeForce 3 @ 1024x768x32.

As stated by an OmniGroup developer a while back, if a game is running under OS X, even if it is not multithreaded (and as such written to take advantage of dual processors) then it will benefit from dual. The sound libraries accessed by the game will be put on a different processor by the OS X kernel, and general OS housekeeping duties will take place on the "free" processor, leaving just the demanding game engine to run on the other CPU.

This is a huge incentive for even lazy developers to code their games for OS X. (Aside from the fact that OS 9 is clearly on the way out.)


blakespot

 

[blakespot]

Re: Re: Re: iMac G4 w/o altiVec?????

Originally posted by Unregistered

AltiVec is the signature feature of the PowerPC G4. They do have a version without it however, and its called the PowerPC G3.

There are other architectural subtlties that differentiate the G3 from the G4. A G4 is not simply a G3 with AltiVec slapped onto it. The G3 is evolved from the PowerPC 603e, while the G4's father was the PowerPC 604. Etc, etc, etc...


blakespot

 

[Unregistered]

Re: Uhm, actually

Originally posted by Sayer
All this whining about bus speed is silly, there is not a direct 33% performance increase in a 133 MHz bus vs 100 MHz. Either get a clue or get off this ranting about crap you are not familliar with.

Actually there is a direct performance increase from having a 33% increase in bus speed. In a system where the clock multiplier is around 8 or 9 you will get a bottleneck in the bus, the processor will process data alot faster than the bus can transfer. Hence the increase in speed of the two systems imac Vs Powermac. I am not sure about the details of why this is, but i know that it works this way.

You are the one who needs to get a clue.

 

[spikey]

oops, forgot to log in.

 

[Xapplimatic]

Thanks Spikey..

Actually, I believe the reason why a 33% faster buss makes a faster machine is that it is the transport highway between RAM and the PPC chip (no, not talking about cache, talking about main memory ) as well as the graphics port controller. If data can't be sped as fast across the buss as any one of those devices wants it, hence a slowdown has occurred and a device made to wait. Surely an 800 MHz processor at times will outprocess how much data can be fed it by a buss that's only 1/8 its speed. Especially given a 128 bit Altivec engine. Any increase in the buss speed is going to greatly relieve potential data bottlenecking at the buss. Why do you think everyone in the gaming department is screaming for DDR-RAM for main memory? They want more data to get across that buss faster. DDR effectively doubles how much can get across Megahert for Megahert.

 

[blakespot]

Well, at least we've got massive L3 caches on the upper end units that does make up for the 133MHz (vs 266MHz DDR) system bus...


blakespot