Multiple cores?

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synthphase
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Multiple cores?

Post by synthphase »

I'm a bit confused after a night of painfully taking apart my laptop to try and reapply thermal paste (apparently you have to take the monitor off these things just to get to the CPU now).. Before that I was playing around with the CPU engine options in Buzz and noticing severe stuttering and CPU overload. So if I just break down and buy a new laptop should I be focusing more on CPU speed vs. # of cores? I remember reading benchmarks awhile back that seemed to say more cores are not too helpful for DSP. But how straight-forward is it?

Just lets pretend that I use two CPU intensive synths on a dual core system. If each synth takes up 50-85% of each core, would the few background processes and overhead from graphics and such just be too much for the system and/or Buzz? If this is true, is it better to replace the two CPUs with 2X more powerful ones or keep the same clock speed and add two more cores?
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mantratronic
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Re: Multiple cores?

Post by mantratronic »

With buzz I think the number of cores is more useful than the individual power. There are only a couple of huge vst's that will take up an entire modern core, and buzz will helpfully sort that out for you with the multithreading option enabled. So 4 cores would give you say 3 big vsts and everything else (buzz and windows) running ok.

Having said that, I dont use many vsts anymore and none of my bmx's have needed multithreading on my current machine. (i7 4 core)

Good luck with the laptop, i assume you found the service manual or something online? Those are generally pretty good now (i take laptops apart to fix annoyingly regularly), just remember to go outside to scream rather than throwing the laptop at the wall when that last tiny screw wont come out! Check that the airflow is ok as well the paste (taking out dust, making sure wires dont cross vents etc)
synthphase
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Re: Multiple cores?

Post by synthphase »

Hmmm. Thanks for the prompt reply. I mostly do everything inside Reaktor now which does have it's own multicore support. Do you think this matters, or would Mr. Polac only know the answer to that?

Yeah I think I got the thing apart without breaking anything.. At this point I think I'll be leaving out some screws from shear spite, not to mention probably mismatching 20 of them putting the thing back together anyway. I realized there are just some thermal pads on the GPU and south bridge. These I want to replace with some copper shims and arctic silver. Don't have the shims though.

Lets start a trend. Everybody bring their nice, cool, desktops to their next show. If it catches on maybe musicians can shead these laptop heat monsters and also the need to be DJ's instead of electronic musicians on stage.
Tiadiad
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Re: Multiple cores?

Post by Tiadiad »

My six-core runs out of breath no problem. Until quantum computers come out 20 years from now I don't think I'll stop chasing DSP.
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UNZ
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Re: Multiple cores?

Post by UNZ »

synthphase wrote:Lets start a trend. Everybody bring their nice, cool, desktops to their next show.
some years ago we brought a midtower desktop + 21" CRT (yes, remember those?) + buzz to a gig where everyone else was playing with laptops + ableton. When time came to pack things up after the gig and get everything back into the car, people looked at us as if we tried to mug the place. Hurling around that big heavy monitor must have looked really suspicious lol.
Tiadiad
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Re: Multiple cores?

Post by Tiadiad »

Pull up resource manager and see your CPU utilization, Buzz doesn't utilize all cores very effectively.
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UNZ
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Re: Multiple cores?

Post by UNZ »

Tiadiad wrote:Pull up resource manager and see your CPU utilization, Buzz doesn't utilize all cores very effectively.
it depends a lot on how your machine graph looks and what plugins you use. i can get it to use all 8 cores (threads) here with multithreading enabled.
Tiadiad
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Re: Multiple cores?

Post by Tiadiad »

I use Buzz x64. I use stricktly VSTs. I buy them, no cracks. I run on turbo 100% of the time (try running several Divas in divine mode with a lot of modulation, voices, tape...), my overhead can easily read over 60%...every time I would simultaneously with Buzz pull up Resourse Manager or Intel Extreme Tuning utility they would both show CPU utilization at around 18% but the clock would read over my base value. Please tell me how you did it man.
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UNZ
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Re: Multiple cores?

Post by UNZ »

Tiadiad wrote:CPU utilization at around 18%.
sounds to me as if mutlithreading is disabled: VIEW / SETTINGS / Multithreading: True

what overhead are you speaking of: the one in buzz's cpu meter ? (i get negative overhead when multithreading is enabled).

btw the buzz x64 is experimental, i would go for x86 version.
also make sure that if you run x64 buzz, use x64 vst, and if you use x86, use x86 vst because otherwise there will be a lot of overhead from the bridging.
Tiadiad
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Re: Multiple cores?

Post by Tiadiad »

The multithreading is switched on. You're right though, I should have said -60%. So that seems to be working. Buzz and system are both x64, so are all of my VST's. I've read in other forums, not Buzz, people talking about their CPU 1 being utilized the most, but then there are others (like yourself) whose systems work the way they are supposed to. I noticed the same thing with Ableton, so it's probably my computer. But then again, when I test the CPU with Intel's ETU it puts all 6 cores on blast without a hitch, and kept it up for the hour long test, no problems. I'll quit bitching though, was too rash to judge, I love Buzz. :mrgreen:
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UNZ
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Re: Multiple cores?

Post by UNZ »

yeah -60% sounds more reasonable and means it works pretty much like it should, pretty good in fact.
yes its possible one core will get more usage of course, it entirely depends on what's going on (graph, machines used, gui's open/closed etc). sometimes it just doesn't make sense for the engine to offload stuff to multiple threads and it will most likely try to avoid thread-hopping (scheduling the same task on different threads all the time might not make much sense and just voids caches / predictions etc). some things in the audio engine /gui are obviously inherently single threaded and will need to run on one thread, so that thread will always be in use. distributing the load evenly across all cores is almost guaranteed to NOT be the most efficient usage of all cores... at least not with something like buzz that has to deal with plugins that don't even know multiple threads exist.

as for "how i did it": i don't do anything special, i don't even care about how the engine will thread my stuff tbh, but if you want to see multithreading in action, something that should parallelize very well is connecting a LOT of generators DIRECTLY to master and no efx or anything.
Tiadiad
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Re: Multiple cores?

Post by Tiadiad »

Thanks man. Most of this stuff is way over my head. I'll try the trick with directly connecting everything to the master output. I always run everything into a transparent brickwall set to -0.1 dB just to make sure nothing clips when I'm writing/mixing. Now that I think about it, it actually makes A LOT of sense. Everything ends up in the limiter before it goes out of the master buss. Maybe that's it. Once again, thanks man.
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UNZ
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Re: Multiple cores?

Post by UNZ »

Tiadiad wrote:Maybe that's it. Once again, thanks man.
no thats not really it, buzz is smart enough to thread whole chains of gear. but the more effects and interconnects between the chains you make the harder the threading problem gets. i just wanted to show you an example case where buzz will be able to make very good use of multithreading, guaranteed. But that doesn't mean its not doing it if you do something else. Running everything into 1 machine before master is not much of a problem.
Tiadiad
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Re: Multiple cores?

Post by Tiadiad »

Hmm...maybe it's a x64 issue? Oh well...
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Joachip
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Re: Multiple cores?

Post by Joachip »

mantratronic wrote:With buzz I think the number of cores is more useful than the individual power.
I'm afraid my experience is the exact opposite. It's very rare to see Buzz use more than 1 or 2 cores. Go for the best per-core floating point performance you can get.

Sad fact: Most CPU tests we see today don't test floating point very well. They use software which is highly optimized (by not using floating point), which makes sites like tomshardware and anandtech useless for figuring out audio performance.
synthphase
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Re: Multiple cores?

Post by synthphase »

Joachip wrote: I'm afraid my experience is the exact opposite. It's very rare to see Buzz use more than 1 or 2 cores. Go for the best per-core floating point performance you can get.

Sad fact: Most CPU tests we see today don't test floating point very well. They use software which is highly optimized (by not using floating point), which makes sites like tomshardware and anandtech useless for figuring out audio performance.
I'm happy to hear you say that as it mirrors exactly my line of thought when I finally made my purchase. I can corroborate it with the performance of the laptop I got as well. I basically went for the newest high core speed mobile chip I could find, noting also something I read stating that I5's have a better performance/power ratio then I7's and that this means they run cooler.

I wish there was more hard evidence in the form of benchmarks for this line of reasoning, but baring that, hopefully google will crawl this forum and save other poor sods from the headache I had to go through when choosing a CPU for DSP.

Another thing of note, and kind of a side comment: It seems like most modern (pop/dance) music is produced using samples and not a lot of actual processing. Playing a ton of sample clips at the same time seems like something that would benefit more from multiple cores. This is borne out by the benchmarks I have seen that state how many audio streams are playing at once in this or that DAW. So we may be twice screwed when looking for viable benchmarks for Buzz.
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onecircles
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Re: Multiple cores?

Post by onecircles »

"Lets start a trend. Everybody bring their nice, cool, desktops to their next show."

That's what I'm going to do, no joke.

This last year I built an ITX computer from a non traditional looking case and a lot of fairly high end parts. If you do go down this route one thing I learned is that you want to get a motherboard with low DPC latency. This is a new issue with the haswell architecture and if it's bad enough can lead to pops or crackles in your audio.
http://en.wikipedia.org/wiki/Deferred_Procedure_Call

This computer is cool though. I'm using it to run my electronic music (buzz/geist) and process my guitar signal (guitar rig). If I can get away with it I'll use it to run a projector as well.

It has a 4770k i7 in it. I elected to go with the i7 largely because I'm already multitasking music sofwares, and if I add in a projector to the mix I'm going to be running 3 programs when I perform live which is probably as far as I'd like to go with the i7's 8 virtual cores. 2 for every program and 2 for the OS.

I haven't played with it live yet though, we'll see how reliable it is. My nightmare is getting a BSOD on stage lol. A lot of people get macs for live music, but that's just not how I operate, I built my own.

It's also given me a reason to start looking at computer bling. It's got a purple power cable and a red and a green usb cable. It looks pretty cool :]
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