CPU Usage on OS X?

I have a Macbook pro dual booting Mac os X 10.4.10 and XP SP2 via boot camp.

I've been working on an ensemble in OS X on Reaktor 5.1.2, lately i've been concentrating on lowering the cpu usage, re-implementing things in core etc.

In OS X my ensemble uses about 40% cpu (or thereabouts), today i booted up XP, and loaded the ensemble in Reaktor 5.1.2 on windows, the cpu usage for the same ensemble was 18-20%

Why does performance under OS X suck compared to XP?
Are the enhancements/support for intel processors' instruction sets that are in the windows version not yet in the OS X version or is OS X to blame?
And will this be fixed in an upcoming update or even Reaktor 6?

 

...anyone got any ideas/thoughts/comments/anything at all?

 

Your processor might run under somewhat throttled conditions under OS X as long as you don't need the whole cpu power. So those figures aren't representative for Reaktor's or the different OSes effectivity. Try loading the same ensemble multiple times until your cpu maxes out.

 

Seems with lo latenties MacOS uses more CPU than with hi... This is not the case in M$ windows. Has nothing to do with Reaktor. All Audio software do that on a mac...

-M-

 

? This has nothing to do with the original question.

 

Thanks for your replies,
I did some testing with the latency thing brought up by MartijnDeluxe and changing the latency does affect the cpu usage slightly (5-10%~), but not nearly enough to effectively double the cpu usage in most ensembles under os x compared to windows...
Unfortunately i'm not sure how to run multiple instances of reaktor under os x so i can't test your suggestion, tymes2, however i have my power settings to better performance so os x shouldn't throttle my cpu?

Most of the programs i use with reaktor are in OS X so using XP is not an option, and although 40-45% isn't bad, 20% gives me alot more 'headroom' for building more.

And if windows can do it on the same machine at 18-22% i dont see why os x can't too. I realize os x and xp are completely different platforms and there might be some discrepancy between the two cpu usage wise, but having ensembles use double the amount of cpu they do on one platform compared to another seems ridiculous to me?

 

What ?

Low latencys use more CPU than w/ hi in MS-Win apps for sure !
And w/ all systems.

KB

 

Sorry - what I meant was "Load multiple instances of the same instrument into one ensemble."

 

Well, not realy on both my PC laptops and desktop. i have RME FF400, RME Digi9632, Edirol FA101.

I have a ensamble that uses 26% on 4ms, 12ms and 20ms no diffrence.

I teach DSP at Calarts (California Institute of the Arts) on Intel Macs and G5's...

On Apple with 20ms Latency the CPU load is simular to PC but a latency of less than 10 ms, uses almost 2 times more CPU load...

Soooo, When i saw:

In OS X my ensemble uses about 40% cpu (or thereabouts), today i booted up XP, and loaded the ensemble in Reaktor 5.1.2 on windows, the cpu usage for the same ensemble was 18-20%

My suggestion would be:

Try using a Latency of 20 on both MacOS and XP boots and see if theres still a diffrence!

Let me know if i'm full of **** ;-)

-M-

 

How much RAM in your Macbook Pro? The OSX kernel uses a lot of RAM by itself; much more than XP does.

ew

 

Martijn: While I'm no expert, I can certainly say this: the reported CPU usage in the Reaktor status bar can be (read: is) misleading at times and therefore doesn't represent a reliable means of comparing performance under different platforms. Lower latency does affect performance under XP as well as OS X, though I cannot say how much. It would baffle me if the actual figures were double cpu to zilch like you seem to have experienced.

 

It uses 125MB RAM on my 2GHz dual G5 (with 6 apps open including R5 and Safari online).
I wouldn't call that 'a lot' by today's standards.

 

No, I don´t say you´re full of **** , he, he ...
But you said in your former post "this is not w/ MS windows" as a comparison.
For me, 12 and 20 ms aren´t low latencys at all (I also use NUENDO/RME hardware, but PCI based).
I also know, my machine is somewhat outdated now, but works fine compared to it´s age.
So I prefer 6ms buffers.
But if I go to lower latency, 3ms p.ex., I see a big increase in CPU, - not only w/ Reaktor but w/ all VSTis.
So my comment was somewhat "general".
It also differs in behaviour w/ the ensembles of reaktor and the ones from the user library as well as count of instances and / or combination of loaded plugins and so on and I´m sure there are differences in behaviour between different machines and system configurations too.

KB

 

Exactly !

KB

 

Add up your app totals; I'm betting those are the 125 MB you're using, and that the OSX kernel's not showing up at all. An empty Reaktor ensemble is 37 MB on my machine...

ew

 

Well, if CPU load goes over 95% it'll start crackling right.

So take a ens that uses say 80% cpu, than start lowering the latency. You will find it stops working on mac where on pc it will play just fine...

Just do the test on youre dual boot macs and see.

-M-

 

Bsides i wasnt trying to initiate a pissing contest about mac and pc. i was just trying to answer the very first question...

-M-

 

It was indeed the kernel I was referring to...

 

2GB of RAM, i dont have access to my macbook until monday but i will try the multiple instances of the instrument idea when can.
Thanks

 

That's what's loaded into physical RAM. Notice that over a gig's loaded into virtual memory...

Any time you have that much of a process loaded into virtual memory, your performance's going to take a hit.

ew