mysterious crackles

[songman]

In sessions with a serious load of Vienna VI's, say 10-12 VIPro's in VEPro + other tracks in Protools 10 (Mac 6 core westmere with 16 GB RAM and OSX10.6.8) I experience the following strange phenomenon. In 95% of the cases the first run of the session after having started up PT will contain a few crackles. I then close the session and reopen it and in 95% of the cases the crackles will then be gone. Can anyone shed light on this strange occurence?

Cheers, Bob.

[DG]

@songman said:

In sessions with a serious load of Vienna VI's, say 10-12 VIPro's in VEPro + other tracks in Protools 10 (Mac 6 core westmere with 16 GB RAM and OSX10.6.8) I experience the following strange phenomenon. In 95% of the cases the first run of the session after having started up PT will contain a few crackles. I then close the session and reopen it and in 95% of the cases the crackles will then be gone. Can anyone shed light on this strange occurence?

Cheers, Bob.

 

 Maybe you don't wait long enough for the samples to be fully loaded.

DG

[songman]

Maybe you don't wait long enough for the samples to be fully loaded.

DG

Quote

No that cannot be it because I am very careful to wait till everything is fully loaded. Would also be a bit strange if I never wait long enough the first time but do wait long enough the second time. That definitely is not the reason.

Cheers, Bob.

[DG]

1. Are you able to say whether the glitches happen in VEP or Pro Tools?
2. Have you assigned enough/too many cores for either PT or for each instance in VEP?

DG

[Cyril Blanc]

DG is right. VEP will display the mixer without samples complettly loaded 

If you want to be sure they are all loaded, you should open "activity monitor/system memory" and wait that free memory and swap used are stable 

If you have "swap used" different than 0 you may not have enough memory, if it over a GB it's realy a problem you need to get more memory !!!

To understand how it is working :

Your DAW will load the sample that are neaded while playing the song, if your disk acces are to slow the samples will not be loaded in time and you will have littles crackels.

If you close the song, the sample may stay in memory (depending if your DAW). If you reload a song and the samples are already in memory it's fine

If you have big cracks, missing note, hanging note, notes not playing in time... this is another story that I have ask VSL to explain and to issue an error massage saying what is happening

[songman]

@DG said:

1. Are you able to say whether the glitches happen in VEP or Pro Tools?
2. Have you assigned enough/too many cores for either PT or for each instance in VEP?

DG

Hi DG,

Thanks for getting back to me on this.

1. It is difficult for me to determine this. What I can say however is that, barring the odd occurence, it will only happen when I am using VIPro2 and/or VEPro5, and then mainly when the load is considerable. In sessions without these I basically have no problems. Protools is running very stable on my present setup (MacPro 6-core 3.33 GHz Westmere, 16 GB RAM, OSX 10.6.8).

2. My playback engine in Protools is:

HW buffer size 512 samples

Host processors 11 (out of 12)

CPU usage limit 90%

Number of voices: usually 64 on 2 DSP's

Delay compensation: long

Cache size: 3 GB

Plugin streaming buffer: level 2 optimized for streaming content on audio drives

My settings for VEPro5 are:

Latency: 2 buffers

Multiprocessing: 7 threads

I started out with 2 threads and gradually went up in an effort to improve the problem.

Best regards, Bob.

[songman]

Hi Cyril,

Thanks for getting back to me on this.

I do not just look at the mixer. I click every single instrument in the mixer and see if the gauge indicating the loading is still there and where it is. I wait till VEPro has indicated that all samples are loaded.

I will do what you said and look at the activity monitor but quite frankly it would be a bit odd if VEPro itself would not give me the correct information as to whether the samples are loaded or not.

Swap used is always at 0. I can also say that on average only 50% of my hard memory (16GB) gets used, Protools will usually be at 1-1.5 GB usage both real and virtual, VEPro 64 will usually be at 1,5-2 GB both real and virtual.

As far as disk acces is concerned, I do not know, the samples for Vienna have their own separate internal SATA disk. I don't know if I can do better than that.

Best regards, Bob.

[DG]

It may even be something as simple as having too many cores assigned to Pro Tools. Have you tried reducing the number, particularly as you haven't even left a full core for the operating system, and none for VEP.

DG

[Thinwood]

@DG said:

It may even be something as simple as having too many cores assigned to Pro Tools. Have you tried reducing the number, particularly as you haven't even left a full core for the operating system, and none for VEP.

 

As I am confronting the same "mysterious crackles" as described at the beginning of this thread: How exactly can we assign a certain number of cores to different softwares in use? I am using Cubase 5.3.3. and (really quite a number) of VI Pros in "legacy" MIR 1860. All that on one big DAW (see specs below). The only menue I stumbled upon regarding the assignment of threads is in MIR, giving me the option to assign a number of threads between 0 and 24.

Any help would be very much appreciated!

Kind regrads

[songman]

@DG said:

It may even be something as simple as having too many cores assigned to Pro Tools. Have you tried reducing the number, particularly as you haven't even left a full core for the operating system, and none for VEP.

DG

I'll give that a try DG. Thanks. Cheers, Bob.