multicore rendering and performance

Hi Ethany

I'm not immensely techie but getting better every day - but I've had the same problem using pianoteq 2 (grand c1 medium) Logic 8 and Dual core imac Problem is solved by disabling multicore rendering and I simply do not understand it. Hope you've managed to sort it out by now!

On Intel dualcore actually works way better than AMD. When I have disabled dualcore processing in Pianoteq, I get 15-50% higher CPU load, because only one core is taking all the work. When it's enabled, both cores do their job equally, and more effectively.

Of course, I'm on windows. So I'd say your Wine is acting up on that setting.

I have been experimenting with 4 speakers through an Audigy 2 ZS multi-channel sound card that I also have and results are really interesting.

Even with cheaper speakers assigned to microphones 3 and 4, if you put the speakers in the same room position as the microphones are with the standard 4 microphones positionning (optimized for standing waves, I presume), the sound field is much closer to headphone listening...great job!

The reason I post this under multicore rendering, is also to report that I get wrong  "Detected CPU frequency" in the Options panel, last one was 12668 MHz.

When I first started using version 3, this value was more accurate, showing around 2200 Mhz the value for one core, but now it shows varying unreasonable high values constantly.

Maybe a bug with the Pianoteq30.prefs file ?

The CPU identification is ok:  AMD Athlon 64 X2 Dual Core Processor 4200+

I also found out that the so-called idle speed that I reported before on one of my cpus is probably caused by the Tascam US-122 ASIO driver, because there is no such CPU usage at idle with the Creative ASIO driver! So PTQ is quite right in displaying 0% at idle...

A last remark, the GUI takes a lot of time to disappear when quitting, maybe an hourglass would prevent us from thinking it's frozen.

Little things, but I am still amazed at the quality of the new version!

Hi Gilles,

A wrong cpu frequency estimate should not alter the behaviour of pianoteq. It is possible that installing "AMD Dual-Core Optimizer Version 1.1.4" ( http://www.amd.com/us-en/Processors/Tec...18,00.html ) would fix that ( I'm not sure, though)

Pianoteq should not be slow to quit, since it is doing nothing special. It could be that your soundcard driver (or midi driver) is slow to close ?

Thanks for the answer But it was in high performance mode

This seems to be a bit erratic.

My power saving settings are

100% processor at high performance

50% processor at power saver

Just run 3 tests with each option closing and restarting Pianoteq 3 x64

HP: 2494, 539, 2494

PS:996, 340, 722

Now repeating the operation

HP:2380, 517, 843

PS:607, 436, 514

Hope this helps

But I do not mean that there is a problem in the performance of Pianoteq, just the number displayed.

In HP the CPU reported use is usually lower than 10%.

In PS below 30%

Anyway the CPU identification is right, so why is needed the second part (detected CPU frecuency)? To show the user that the CPU is not used at full speed?

Just to add more confusion

Just tried with my desktop PC, a core 2 duo 6600 at 2400 MHz

5 times and always perfect, 2400

Regards

That looks like a good explanation. In fact version 3 doesn't always start on the same core as 2.3 did! Sometimes (rarely) it uses only a single core.

Another AMD quirk I guess...I'll give a try to the Optimizer you mentioned.

Maybe this also explains the slow shutdown.

Thanks!

I am not surprised that wine has issues with multicore rendering, this is something that is very demanding on the scheduler, and as wine is just a layer above linux, it is hard to ask it to mimic the windows behaviour. Especially if you are using stuff like wine-asio.

However if you are satisfied with single core perf. I would suggest that you do not lose too much time with multicore !

I am happy to see the polyphony metering where I can hit a single note, then do a short passage and watch as the poly doesn't climb until many notes, and sos or sustain pedals come into play.
With most Piano libraries it is alarming to watch the polyphony sky rocket from the massive amounts of layers that my controller cannot even possibly access.
I have multicore rendering on an E8600 DAW and hardly see a CPU hit.
I have always used Scope DSP cards to avoid being a slave to a CPU.
So most of my CPU cycles go to romplers, Giga and Modartt.
I have played for 2 days, and today I will report back with results of disabling the reverbs, etc.
I route hardware effects into my projects because I hate the sound of IR's and see no need to waste CPU cycles on them.
There's a possibilty I might keep different IR's on the Grand, Upright preset, Rhodes and Wurly though, as they sound pretty good and I can apply a splash of the PCM91 to all of the above while altering their Early reflections and mic placements. They are all on the same channel so this might be necessary.
GigaPulse's Pedal Down IR's were all I ever used before, so I will definately be saving cycles by removing those libraries.
Many developers of gigantic romplers are probably watching Modartt with a cautious eye.
These same developers offer no sostenuto pedal, or a Harmonic pedal,...they need tons of HDD space, lot's of RAM, quad core CPU's, etc.etc.......and here comes the low power laptop masterpiece which has to make them nervous. But then again, many rompler lovers seem to enjoy all of the pictures and dozens of layers that can only be accessed by a sequencer editing pass.
I happen to love all of them, but I will be using P3.0 for my live work, and I finally have a 3rd hand thanks to the sostenuto feature, which the rompler developers don't think is necessary.
That little trade-off choice just might come back to bite them in the arse....

You were right, Julien! I installed the dual core optimizer and now I the get correct frequency each time. I notice also that there seems to be less parallelism when looking at the task manager graphs, but total cpu usage is the same as before.

Probably, as was already mentioned, multi-core rendering of pianoteq is better with Intel Core 2 duo. Doesn't matter, it sounds great!

I still have the slow shutdown most of the time, maybe other AMD users could confirm if they have the same behavior.

maybe you could try to uncheck all midi devices in the pianoteq options/device panel, and see if it still slow to quit. That would be a good hint. You can also select "none" as the audio output and see if it helps ? If not, then you can try to uncheck multicore rendering ?

I have an Intel Pentium M 1.86GHz, single core CPU, single soundcard Edirol UA25 and I get the quitting "bug" too.  I'll check when I'm at home which MIDI inputs PTQ is set to listen on.

Best//Neil