New Mac Pro - 6 or 12 cores for Logic?

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Level 1

2 points

New Mac Pro - 6 or 12 cores for Logic?

Hi

I'm about to place an order for a new Mac Pro, to replace our previous Mac Pro.

Does anyone know if the 12 or the 6 core model is likely to deliver the best performance with Logic? The 6 core is clocked higher than the 12 core - 3.33GHz v 2.93GHz - and it's hard to get a handle on whether the additional cores are likely to compensate for the lower speed.

Does anyone who knows more than me about this stuff have a view? Is Logic even able to fully utilize all 12 cores?

On our current 8-core system I tend to see activity across 4 or 5 cores only, and the times we hit performance issues are when 1 particular core is being maxed out, even though others are idle or running at low load. That said, we're still using OS 10.5 so maybe load balancing is improved with 10.6.

Any help or advice very much appreciated.

Jules
http://www.trailermen.com

Mac Pro 8 Core, Mac OS X (10.4.10)

Posted on Aug 12, 2010 6:40 AM

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Answer 1

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Mike Connelly

Level 4

1,791 points

Aug 12, 2010 7:32 AM in response to Trailerman

Nobody knows yet. I'd wait until they are shipping, which should only be a week or two, and see what the user reports online are from Logic users.

Also, as you have seen, Logic is not well optimized for all numbers of cores. When the new hardware is released, it's possible that Logic will be updated at some point to better utilize more cores, or it may take months or years to catch up with the hardware (the current situation). If you have an eight core already, personally I'd stick with that since it's not being used to its full potential yet. Is it a 2008 or 2009 MP?

You may be able to adjust your sessions to better balance the load, check this out:

http://support.apple.com/kb/HT3161

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Answer 2

Trailerman Author

Level 1

2 points

Aug 12, 2010 9:11 AM in response to Mike Connelly

Thanks Mike.

I'd love to wait and see. Unfortunately my current Mac is literally dieing on me - not because it can't handle the load, it's had some memory problems, now replaced, but is still refusing to start (blinking blue light with no activity) about 2 out of 3 starts. I can probably nurse it along for another week or so, but fear it may not survive for long and I have no Applecare. It's a 2008 MP.

I wonder why they didn't offer a 12 core model at 3.33 GHz. Seems a strange choice. I'm tending towards the additional cores, as alot of plugins are now using their own standalone server-type applications (Kontakt 4, Vienna Ensemble Pro), so assuming there's a reasonable amount of control over processor affinity in 10.6, it may make it easier to spread the load. I just never see more than one core overloading at the moment, which makes me wonder ...

Thanks again for your help.

Jules

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Answer 3

zukodany

Level 1

0 points

Aug 12, 2010 11:17 AM in response to Mike Connelly

wow! Is this true? (scroll down below for the last paragraph of the article you have presented- http://support.apple.com/kb/HT3161):
"It's a good idea to keep a track that uses an Audio channel strip selected in the Arrange window, unless you're actively playing or recording to a Software Instrument."
So in general it means that whenever running a session, any session, I would get better performance by selecting an audio track than an instrument track? if so I wonder how better it would perform? can't wait to try...

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Answer 4

Aug 12, 2010 11:42 AM in response to Trailerman

That's definitely true. When you play back with an instrument selected, the app has to be ready for you to play back in real time, and it uses a lot more CPU. I have an empty dummy track in all my sessions and when the machine starts to chug, I have it selected for playback. It would be great if apple could figure out a way around this, especially since it's impossible to select instruments without record enabling them.

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Answer 5

Pancenter

Level 6

14,644 points

Aug 12, 2010 2:50 PM in response to zukodany

zukodany wrote:
wow! Is this true? (scroll down below for the last paragraph of the article you have presented- http://support.apple.com/kb/HT3161):
"It's a good idea to keep a track that uses an Audio channel strip selected in the Arrange window, unless you're actively playing or recording to a Software Instrument."

As Mike said, very true... and especially noticeable on the lower power G5's.
When an Instrument track is selected it's a "live input" which uses resources. Oddly, I don't think other DAW's have this problem but I would have to check on that.

pancenter-

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Answer 6

mauoq

Level 1

9 points

Aug 12, 2010 3:53 PM in response to Mike Connelly

Would deactivating the Record Ready button be of any help?

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Answer 7

Trailerman Author

Level 1

2 points

Aug 13, 2010 12:17 AM in response to mauoq

Although there are things you can do to try and balance the load, in my personal experience, once you have a CPU overload issue affecting one core, it's very hard if not impossible to resolve it. This is because Logic uses a fairly stright forward processor affinity algorithm, whereby one track runs on one core, the next track on the next core etc.

Really Apple need a slightly more sophisticated approach to load balancing so that specific plugins that place massive load on the CPU are moved onto their own core.

In the meantime, I guess we have to just hope that the new Intel architecture used in the newest Mac Pros offers enough performance gains to leave sufficient CPU overhead for handling really big projects.

I'm inclining towards the 12core Mac Pro in the hope that load balancing becomes more developed, and because Apple confirmed to me yesterday that Logic WILL use all cores of a 12 core machine, and also told me they at it will run more efficiently on a 12 core than a 6 core machine.

Jules
http://www.trailermen.com

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Answer 8

Eriksimon

Level 6

15,416 points

Aug 13, 2010 4:41 AM in response to Trailerman

Trailerman wrote:

Apple confirmed to me yesterday that Logic WILL use all cores of a 12 core machine, and also told me they at it will run more efficiently on a 12 core than a 6 core machine.

Someone on the phone told you, or is this info published online somewhere by Apple? Where? Are you sure this isn't another salesperson not really knowing what they're talking about? Logic has never been able to use more than 8 real and/or virtual cores even if Activity Monitor shows more than 8.

I just called the +Future Store,+ which is the specialist for Mac pro video and audio here in NL, and they say they have to wait and see until they get their first 12 core MP (in ± 3 weeks). They also say they never trust what any manufacturer says about what their products can do, they always have to test and see for themselves. As soon as they have it, I will go over there and test it myself.
Unless someone can post a screenshot of Logics' CPU meter showing 12 cores (24?) before that...

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Answer 9

Trailerman Author

Level 1

2 points

Aug 13, 2010 6:28 AM in response to Eriksimon

The information was given via online chat, and I have a log of the chat session and the name of the rep. I specifically insisted that the rep check with a pro-audio expert before responding.

I've also confirmed it with the main pro-audio/Apple dealer in the UK. In both cases I was told categorically that Logic will utilize all 12 cores of a 12 core machine.

Jules
http://www.trailermen.com

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Answer 10

spheric

Level 3

699 points

Aug 13, 2010 6:57 AM in response to Trailerman

Trailerman wrote:
The information was given via online chat, and I have a log of the chat session and the name of the rep. I specifically insisted that the rep check with a pro-audio expert before responding.

I've also confirmed it with the main pro-audio/Apple dealer in the UK. In both cases I was told categorically that Logic will utilize all 12 cores of a 12 core machine.

Unless that dealer actually HAS a machine in stock that he can use for demo, or has been explicitly demoed/verified this by Apple engineers working on Logic on a 12-core machine, I would take the dealer's words with a HUGE chunk of salt, as no previous computer has ever allowed Logic to access more than eight cores - even though the previous Mac Pros supply 16 to the system.

We shall see - I certainly wouldn't base my decision on that info at this point.

Though, of course, one hopes that the limitation will be overcome at some point before the new 12-cores outlive their usefulness…

Message was edited by: spheric

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Answer 11

Aug 13, 2010 8:12 AM in response to Trailerman

Trailerman wrote:
Although there are things you can do to try and balance the load, in my personal experience, once you have a CPU overload issue affecting one core, it's very hard if not impossible to resolve it.

What plugin can max out a core by itself? Of course it's possible but I have yet to see anything even come close.

I'm inclining towards the 12core Mac Pro in the hope that load balancing becomes more developed, and because Apple confirmed to me yesterday that Logic WILL use all cores of a 12 core machine, and also told me they at it will run more efficiently on a 12 core than a 6 core machine.

I would never believe anything coming from apple tech support or other customer reps, there are tons of documented examples of people getting info that was wrong.

And even if it's true, if they didn't give you a time frame it could mean that Logic will use all 12 cores with a software update...and that update could be two years from now. Did they give a timeframe? Or did they mean that the current version of Logic will use all 12 cores?

Also, the 12 core machines actually have 24 cores including the hyperthreading cores, did they address whether those are/will be supported? They work fine on the current quad i7 and quad xeon machines, but not on the octos since there seems to be a limit of eight cores.

And I would hope it will run more efficiently on a 12 core than a 6 although I'm not ruling out the possibility of poor performance on either with the current version of Logic. We'll see when they ship and people get to run Logic on them.

I'd be curious to read that part of the chat log if you're willing to post it.

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Answer 12

Trailerman Author

Level 1

2 points

Aug 13, 2010 9:52 AM in response to Mike Connelly

Hi Mike

What can I say - I've asked the two parties that I am directly or indirectly entering into a contract with for confirmation on a specific technical point, and been told the same by both. If they're wrong the system will be returned.

My log of the chat is pasted below. I've removed the reps name, but the text is reproduced verbatim.

My system will be here in two weeks. I'll let you know how it shapes up.

All the best

Jules

You: OK. I am considering either the 2.93GHz 12 core or 3.33GHz 6 core machines. I need to know which will deliver optimum performance with Logic Pro, and whether Logic Pro is able to fully utilize all 12 cores of the 12 core machine.

Apple Rep: Just another minute...

Apple Rep: I will be happy to get that for you.

You: No worries. I'd like to make sure that I get clear advice, so if you need to consult a Logic developer I can contact you later.

Apple Rep: I am checking for you currently.

You: Sure

Apple Rep: Thank you.

Apple Rep: Logic is able to be distributed over all 12 cores. With the 12 core machine it will give you a better overall performance.

You: Thank you. Can you just confirm that that information has come from a Logic or pro audio expert? Many thanks

Apple Rep: Yes I did confirm that with our experts.

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Answer 13

Aug 13, 2010 10:00 AM in response to Trailerman

Interesting, thanks for the info. It sounds like they think the current version will use 12 cores (I assume if that's the case it will use the 12 main cores but not touch the HT cores, like the 8 does). There's no way it's going to "fully" use all cores since it doesn't do that on any mac, but hopefully it will at least use some of all 12. If you do get the 12, please let us know how it works with Logic.

If their info does turn out to be wrong, I hope you are able to return the system without having to pay a restocking fee. I don't know if they make exceptions based on reps giving out incorrect info or if you'd need to make a stink or take it up with your credit card company or elsewhere.

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Answer 14

Aug 13, 2010 10:04 AM in response to Trailerman

I wonder if that rep was asked if the current eight core machines used all cores (including HT) what the answer would be? I'd bet there would be reps (and audio "experts") who would say yes.

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Answer 15

Eriksimon

Level 6

15,416 points

Aug 13, 2010 10:26 AM in response to Mike Connelly

Rethorical Q: Did the sales rep really speak, to whom exactly?

So what if it is true? Imo there are two options if Logic uses all real and HT cores on the new MP's:
1. Logic gets updated at or around the same time. This will benefit all dual processor Mac Pro owners, as they would probably get 8 extra virtual cores. Or 2. 'Something is different' in the new Xeon processors that enables Logic 7.2.3 and higher to use more than 8 cores. Doesn't seem likely though.

Message was sceptified by: Eriksimon

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