nMP CPU choice for Mainstage/Logic

seisend said:

However, what did you guys experience in real world performances?
Would you go with 12 core to be 100% save or do you think the 6 core will do it or might be even saver choice given the headroom with the extra clockspeed in live situations.

Click to expand...

Your question is almost impossible to answer. I don't fully understand your proposed workflow, so can't really judge how much load you're going to be placing on the system. If you're using it mainly for live work (which I think is what you're saying) then I very much doubt you'll need lots of cores.

The thing that eats CPU load in Logic Pro is plugins and Aux Tracks. These days, you can run hundreds of plugins and the system won't blink, so you'd really need to be hammering it to definitely need 12 cores. I run a 1000+ track template in Logic Pro X on a 2010 12 core and it runs great.

However, Logic still has one enormous handicap, and that is that (as I understand it) all Aux Channels run on a single core. The result of this is that one core tends to spike in very heavy projects. This is borne out by my own experiences - a typical project will show average loads of around 30-40% on 11 cores, with the 12th core up around 80-90% (I use a lot of aux channels).

Bottom line, in some respects the lower spec systems may perform better for Logic users who typically see single core spikes, because they offer higher clock speeds, meaning each single core can deal with higher loads. Overall, I'd still think a 12 core will perform best, as long as you find ways to optimize your Logic Pro songs to keep the load as well balanced as possible.

Hope this helps a little.

Jules
http://www.trailermen.com

seisend said:

Hello there

I will buy the new Mac Pro and will use it in a live setting with Mainstage 3 alongside Apogee Symphony I/O connected via Thunderbolt...
....

I am willing to invest around 7K or more and have this setup in mind:

- 32GB Memory Ram
- 1TB Flash Storage
- D300 configuration
- 6 or 12 core.

Thanks

Click to expand...

Pretty good chance that $7K won't buy 12 cores plus the other stuff you want ( $7K is suppose to include the TB to Symphony interface or not)

Intel's E5 2697 v2 price is $2614. Apple's price is likely around 30% higher so around $3,400. If swap out E5 1620 v2 might drop by around $300 so about $3,100. So, $2,999 + 3,100 ==> 6,099 already.

1TB flash ... Apple is change $1,000 on the iMac for that upgrade ( and $800 over MBP 15" entry's 256GB ). This is a faster SSD so I doubt it is less. So over $6,899 and still haven't got to the RAM yet.

3rd party RAM will be cheaper than Apple's options, but the vast majority of the $7K is gone at this point. ( it is probably only a bit over for 4 8GB DIMMs though. )

With a $7K upper bound and those kind of storage requirements 8 cores is probably closer to the upper cap if also need to cover TB perheripals. Also, you'll likely want to put another flash storage device into the completed deployed system also. If all this stuff is live probably want to spread the storage latencies around to more than just one ( admittedly fast) storage device.

I was wondering if you forgot there is an 8-core. I think it will be the performance sweet spot, like The Hex was before. It has the highest single thread speed of the batch, and can HT up to 16 threads.

If I can afford it I'll get the 8-core and D700, depends what the D700 costs, I may need to retreat back to the 6-core if the D700 is a $2k or more BTO by itself.

I figure the 8-core will start around $5200-$5500 depending on markup.

seisend said:

I believe the 12 core upgrade will cost around 2k and the storage upgrade around 1k. Anyway, let's not argue further about this part as we all don't know in the end..

Click to expand...

It isn't much of an augment. Intel's price is $2614.

http://ark.intel.com/products/75283/Intel-Xeon-Processor-E5-2697-v2-30M-Cache-2_70-GHz

That isn't a unknown or a 'wait and see' about that price. So, Apple selling $2,614 processors at $2,000 isn't going to happen. The E5 1620 v2 is only $294.

http://ark.intel.com/products/75779/Intel-Xeon-Processor-E5-1620-v2-10M-Cache-3_70-GHz

Even putting aside Apple's profit mark up, trading in a 1620 v2 for a 2697 v2 is still a $2,320 net increase in costs. Even if that was a 1650 v2 ( six core, $583 http://ark.intel.com/products/75780/Intel-Xeon-Processor-E5-1650-v2-12M-Cache-3_50-GHz ) it is till over $2K ( $2614 - $583 = $2,031 ).

The 1620 is relatively not too expensive an Intel CPU and the 2697 definitely is extremely expensive (it cost about as much as a whole Mac Pro). There is no real debate about that.

It is also not much of an argument that Apple is going to put a profit margin on top of the processor upgrade. They do it with every other Mac product and currently with the Mac Pro. Can debate weather it is 25%, 30%, or 35% , but it is going to be there.

@deconstruct60

So you would spread the Sound libraries on a few external TB SSD Drives? Don't you think the internal 1TB PCI-E will be more than enough for a 300 GB Library?

Click to expand...

Not particularly the sound libraries, but the OS (and any other background programs ) is running off this drive also. Similarly if want to record a different target makes those two I/O flows ( library and recording) independent.

It is more so piling a couple diverse workloads on top of the same drive. The other factor is that when give a SSD controller room to work the bandwidth and latencies are generally better.

http://www.anandtech.com/show/6489/playing-with-op

It is likely not just going to be a 300GB sound library. It is going to be that and many GBs over time of other stuff if only have a single drive. With two drives, "other stuff" can be sent to another drive over time.

seisend said:

Thanks for your input. Well, I feel you are a bit pessimistic. Maybe you are right given the current circumstances. I don't think they will add 3000$ a Processor upgrade for 12 Core. We will see.

Click to expand...

The formula

( Intel's price for alternative CPU * 1.3 ) - ( Intel's price for CPU being removed )

works fairly accurately for most currently Macs in the online BTO store. Apple rounds numbers so they match their pricing scheme, but for approximate estimates it works. It is a quantitative measurement of what Apple does. The question mark for new machines is far more what new prices Intel will charge far more than what formula Apple is using to calculate BTO CPU pricing.

I am not sure if even a 6/8 Core will do a faster Job due the higher clock rate than a 12 Core eventhough Mainstage takes full advantage of all cores.

Click to expand...

"faster" isn't so much an issue as fast enough. Can always buy more horsepower than you need.... it won't necessarily make things go any faster. Audio is sampled/created at fixed rates if weaving into a live stream. If synchronizing with real time the computations can't particularly ran ahead of that.

You have about 8 sources here. ( 5 + approximately 3 ). If the data is coming at 100's if kHz and the CPU cores are clocking at GHz rates you have a 4 orders of magnitude difference. One core per source is rather generous. Even if "loose" one of those to 'overhead', it is still 3 orders of magnitude difference.

If have an app that constantly needs to flip-flop between highly parallel and single threaded sections then the 8 core model has the broadest dynamic clock range ( 900 Mhz : still in that 3 orders higher range) . It isn't exactly inexpensive either $1723 :

http://ark.intel.com/products/77912/Intel-Xeon-Processor-E5-1680-v2-25M-Cache-3_00-GHz

[ likely up in the $1.9-2K range in price for an upgrade from the base Mac Pro. Although a E5 1600 series option it is priced like at 10 core E5 2600 one. ]


Without the flip-flopping a 10 (which Apple doesn't offer) or perhaps 12 core model would make more sense if primarily on just multiple core workloads.

Of course in Logic Benchmark it makes sense to have 12 core given that the tests rely on the number of tracks which is not really the case in a live situation. I will never use 100 Tracks in one Patch !

Click to expand...

Because audio has relatively limited data bandwidth the only way to justify these top-of--the-line CPUs is by cranking up the track count.
With 2+ GHz multicore CPUs , double digit GB RAM capacities, and SSD very high IO ops rates, there are very few latency issues for two handfuls of audio tracks to run into.


P.S. the 12 core model in E5 2600 v2 series is bit early. Initial rumors had v2 capping out at 10 cores. Looks like Intel got the 12 core design varient working slightly ahead of schedule. The pricing reflects that. Very bleeding edge so get charged extremely bleeding edge pricing. The affordable 12 core E5 2600 isn't coming until v3 arrive probably late 2014 or possible pragmatically early 2015.
I can see Apple pushing for this early though because this way the Mac Pro doesn't 'backslide' on max core count, even though dropping the dual CPU package configurations. the "more affordable" range of dual CPU options is going to disappear for a generation or so until a combo of Intel updates and shrinks packs all that into one package at more affordable price levels.

seisend said:

Does Logic / MainStage use 24 Threads?

Click to expand...

Can't speak for Main Stage (don't use it) but Logic uses up to a maximum of 16 threads on our 12 core system. I think this is a limit hardwired into Logic: if 'processing threads' is set to automatic, it uses 12. This is on Mavericks which does show 24 'virtual' cores on our rig.

Whether this means that an 8 core will outperform a 12 core I don't know, but it's possible. In theory the 8 core will give you 16 threads running at a higher clock speed than the 12 core. Personally I'd probably still choose the 12 core, as I'd rather have the redundant overhead for other applications, but this makes the 8 core look like a solid choice.

Jules

seisend said:

Thanks for your reply. Are we talking about Logic Pro X?

Click to expand...

Yes

Marco Arment posted a fine synopsis of the CPU options for the nMP the other day:

http://www.marco.org/2013/11/26/new-mac-pro-cpus