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Mac Pro 8-core performance on Leopard

F

firstyearprof

macrumors member
Original poster
Apr 16, 2007
52
0
Hi folks,

Since the new 8-core Mac Pro was shipped several months back, there has been belly aching about the "Frankemac's" inability to fully utilize those 8 cores. According to some, it's like you're paying for 8 but really getting 5 1/2 or something. My understanding is that this is both a hardware and a software (OS) issue. On the hardware side, the intel chips weren't built for distributing between 8 cores - Stoakley-Seaburg multicore management chipsets should be better at this, but haven't been incorporated into the Mac Pro's yet. On the OS side of things, Tiger is "not really aware of topology and the threading in the kernel and the drivers and the program calls themselves are not yet well suited for over 4 cores." (from Rocketman).

SO, now that the beta Leopard is on the loose, does anyone know how the 8-core Mac Pros perform running Leopard vs. Tiger? Has anyone seen any write-ups about this? Or any educated guesses?

Also, what's the best guess for the next update (hopefully to SS chipsets)?

Thanks,

Matt
 
Leopard should be better in taking advantage of 4+ cores, but we ahve no real confirmation on this.

Oh, and the SS should come in the next MP update, the only problem is that we do not know when it will be..:eek:
 
This is the big question. Some have said Stoakley-seaburg wasnt that much faster, some say it will enable all cores. Nobody really knows. As far as leapord some have said there is no speed up from 64 bit.

We shall see in the next few months what is up.
 
Well the core management is going to be better from what apple has said. Now how much performance boost you will get..that remains to be seen.
 
No one here is going to notice a difference with 8 Cores unless you're using Multi-threaded applications such as Adobe After Effects CS3 which supports all 8 Cores.

I don't see why you would need 8 Cores unless you're doing high end stuff.

The operating system (OSX) already supports all 8 Cores..and even does 64bit side by side with 32bit in Leopard. It's upto the application to enable this power.
 
SDAVE said:
No one here is going to notice a difference with 8 Cores unless you're using Multi-threaded applications such as Adobe After Effects CS3 which supports all 8 Cores.

I don't see why you would need 8 Cores unless you're doing high end stuff.

The operating system (OSX) already supports all 8 Cores..and even does 64bit side by side with 32bit in Leopard. It's upto the application to enable this power.
Click to expand...

Agreed. Its up to the application. I ran tests under adobe photoshop with numerous macs. One test I got these results

Powermac G5: 49 sec
Mac Pro 2.66ghz: 17sec
Mac Pro 3ghz 8 Core: 6 seconds

So even with photoshop 7.01 under rosetta there is a huge speed gain. Now lets hope all apps go this way in the future.
 
Just finished another benchmark

Encoded an Eyetv recording to ipod format 640x480 H.264.

Show duration was 1hr 1min (1:01)

Here are the results

- Mac Pro 2.66ghz Quad 5gb ram: 1:07:37
- Turbo.264 on Mac mini 2gb ram: 1:20:17
- Mac Pro 8 Core 3ghz 8gb ram: 0:46:52


So, nice speed up. Lets see what the results are in October when quicktime is 64bit and multiprocessor efficient.
 
I think us 8Core owners are covered for the future.

The developers have no choice but to support multi-core CPUs because CPU manufacturers have hit the wall...if anyone remembers, the race was with how many GHz the next CPU can go to...but now it's all about multi-cores.

I bet by mid 2008, multi-core apps will be the norm. Even simple applications will support multi-cores.
 
Let me get this straight - Apple have released an 8 processors machine that, by their own design, choice of components and software; cannot address them? And this is their highest priced, most professional computer!

When it came out, I wrote to MOTU and asked if Digital Performer could access all 8 or did DP need a re-write and they said it could already see them. See 'em but not use 'em I suppose! This is terrible news.
 
Henri Gaudier said:
Let me get this straight - Apple have released an 8 processors machine that, by their own design, choice of components and software; cannot address them? And this is their highest priced, most professional computer!

When it came out, I wrote to MOTU and asked if Digital Performer could access all 8 or did DP need a re-write and they said it could already see them. See 'em but not use 'em I suppose! This is terrible news.
Click to expand...

Yes. But they totally have to re-write every application and the OS to do so, which they are doing. Yes, they should have done it sooner but the CPUs from intel came out pretty fast. I don't know if writing an application for 2 cpus is the same as writing for 8 though. If it is then they are at fault since dual processor macs have been around for ages.
 
macenforcer said:
Yes. But they totally have to re-write every application and the OS to do so, which they are doing. Yes, they should have done it sooner but the CPUs from intel came out pretty fast. I don't know if writing an application for 2 cpus is the same as writing for 8 though. If it is then they are at fault since dual processor macs have been around for ages.
Click to expand...

If it takes a year to release an iMac; how long is all this re-writng going to take? It will be out dated soon and with Intel price reduction - over-priced too. If it needs new hardware as the OP suggests as well to achieve it's potential, only Rev B people will be buying a true Octo Others will feel duped surely after buying such an expensive ham-strung comp?
 
Henri Gaudier said:
Let me get this straight - Apple have released an 8 processors machine that, by their own design, choice of components and software; cannot address them? And this is their highest priced, most professional computer!

When it came out, I wrote to MOTU and asked if Digital Performer could access all 8 or did DP need a re-write and they said it could already see them. See 'em but not use 'em I suppose! This is terrible news.
Click to expand...

No, this is certainly NOT the case.

Mac OS X has supported multiple cores since the beginning. If you're using only one processor-intensive application at a time the actual benefit you will get from eight cores has always depended and will continue to depend on how well threaded that application is. Most high-end applications these days are quite well threaded, and matters will only improve for other applications as multiple cores become more mainstream. Judging by what MOTU told you, Digital Performer is threaded enough to make use of all eight cores, but there's no need to take their word for it! Fire up Activity Monitor and see for yourself!

The only question here is whether the improved low level handling of cores in Leopard will have a noticable effect on the performance of threaded applications running on multiple cores.
 
Henri Gaudier said:
If it takes a year to release an iMac; how long is all this re-writng going to take? It will be out dated soon and with Intel price reduction - over-priced too. If it needs new hardware as the OP suggests as well to achieve it's potential, only Rev B people will be buying a true Octo Others will feel duped surely after buying such an expensive ham-strung comp?
Click to expand...

I don't know about ham-strung. Did you see my benchmarks posted above? Its clearly faster already. Leapord will make it even faster.
 
macenforcer said:
I don't know about ham-strung. Did you see my benchmarks posted above? Its clearly faster already. Leopard will make it even faster.
Click to expand...

I meant ham-strung in the sense that it is not running at optimal performance, if, as the OP alludes correctly, it is both a hard and soft issues. Now, Leopard in it's first revision will go someway to sort this out and no doubt it will be refined with time but as for any hardware issues then present owners will be in for a disappointment.

Nutter, I've checked my Activity Monitor and my G5 iMac is only working on one processor! This Octo problem is worse than I thought!:D

It was "terrible news" because I'm scheming like a Goblin in order to get one next Rev and I want it to be great now and superb by Rev B.
 
Henri Gaudier said:
Let me get this straight - Apple have released an 8 processors machine that, by their own design, choice of components and software; cannot address them? And this is their highest priced, most professional computer!

When it came out, I wrote to MOTU and asked if Digital Performer could access all 8 or did DP need a re-write and they said it could already see them. See 'em but not use 'em I suppose! This is terrible news.
Click to expand...

Woah, back the truck up... before this gets out of hand. Tiger (MacOS 10.4.x) can use 8 cores. Various tests by Apple and 3rd parties has already proven this. As long as the application is multi-threaded enough, it will use as many cores as possible. But, some tests seem to indicate that there could be further optimization of how MacOS X manages the threads among the cores. There seem to be a few inefficiencies that could be improved upon. As well there was mention of a memory bottleneck which seems to mean that the 8-core Mac Pro is better at CPU intensive tasks and not memory intensive tasks. Of course there are very few applications that are this multi-threaded. Most common daily-used applications won't use all 8 cores.
 
Nutter said:
The only question here is whether the improved low level handling of cores in Leopard will have a noticable effect on the performance of threaded applications running on multiple cores.
Click to expand...

For example often if your running 1 CPU intensive thread it will jump between your 4 or in some peoples case 8 cores. This is incredible in inefficient. As it has to move the cache on the CPU between the CPUs. Leopard is suppose to fix this. Also if you have a couple CPU intensive threads it still swaps them between cores. You just can't always see it in activity monitor.;)
 
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