RAM usage in the Interpolated Delay

Sound synthesis techniques, DSP and related mathematics

Moderators: electrogear, exonerate

RAM usage in the Interpolated Delay

Postby Acrobat on Thu May 15, 2008 2:24 am

The interpolated delay requires to declare the amount of samples you need for the delay. Ok.
But How much PC memory will it take?

I would like to set it to execute at least 132300 samples (1/1D of a bar).. to be playable with a 2Gigabytes RAM PC...

That will probably require a simple calculation based of byte size, but I don't know where to start... please help..!
User avatar
Acrobat
smaniac
 
Posts: 1660
Joined: Mon Jun 04, 2007 10:50 pm
Location: Roma, Italia

Postby Andrew J on Thu May 15, 2008 2:35 am

Each sample is represented by a 32bit float, which is 4 bytes. So 132300 samples is 132300 * 4 / 1024 = 516.8 KB.

BTW, are you assuming a fixed sample rate?

-Andrew
Andrew J
smanatic
 
Posts: 616
Joined: Tue May 29, 2007 4:53 am
Location: Australia

Postby Acrobat on Thu May 15, 2008 2:50 am

Andrew J wrote:Each sample is represented by a 32bit float, which is 4 bytes. So 132300 samples is 132300 * 4 / 1024 = 516.8 KB.

BTW, are you assuming a fixed sample rate?

-Andrew


ops, no, how will your calculation change at 192Khz, for example?
thanks a lot andrew, you're always ready to those sort of things...! :D

Hey, only 512K? :o
Mmmh now I'm think that I could simply create some silence in an audio editor and watch the filesize... oh and your calculation is x2 since I'm in stereo...
User avatar
Acrobat
smaniac
 
Posts: 1660
Joined: Mon Jun 04, 2007 10:50 pm
Location: Roma, Italia

Postby MyCo on Thu May 15, 2008 4:44 am

Well, you also have to take SSE into your calculation. SSE uses 4 channels, so each memory address in a code module is 32Bit x 4 channels. Which means at 44,1kHz sample rate, its real size is:

44100 sample/second * 4 float/sample * 4 byte/float = 705.600 Byte = ~700kB/second
User avatar
MyCo
smaniac
 
Posts: 1016
Joined: Mon Dec 19, 2005 1:43 am
Location: Germany

Postby Andrew J on Thu May 15, 2008 4:58 am

Nice pickup Maik.

:blush: for me
Andrew J
smanatic
 
Posts: 616
Joined: Tue May 29, 2007 4:53 am
Location: Australia

Postby aliasant on Thu May 15, 2008 6:06 am

Well. I guess most of us has a couple of rams available or even more.......

Is this really an issue? Is there more to it?

Great calcs Andrew and Myco.
It's never to late to be late.....
http://martinrodensjo.smugmug.com/
User avatar
aliasant
smunatic
 
Posts: 2386
Joined: Sat Dec 30, 2006 5:49 pm
Location: Sweden

Postby Acrobat on Thu May 15, 2008 7:08 am

aliasant wrote:Is this really an issue?


I think not a problem at all, and for any PC,
I just wanted to figure it out a bit,
what's the real deal, the weight on RAM addressing those MEMs... :)

I guess I can raise the amount far more than I was doing,
thx to u all, now it's all up to me re-calculating in my schematic.. :D
User avatar
Acrobat
smaniac
 
Posts: 1660
Joined: Mon Jun 04, 2007 10:50 pm
Location: Roma, Italia

Postby oddson on Thu May 15, 2008 6:16 pm

FYI...

I use a 20 second (at 44.1 KHz) four channel delay in my long-delay projects.

I took the delay alone and made a VST (no controls, no GUI) and it added 19.9 MB to eXT's memory usage compared to the theoretical minimum of 13.4 MB. A null VST (no processing straight-through) made in SynthMaker adds 6 MB so there's very little unaccounted for.
oddson
wiki guru
 
Posts: 3883
Joined: Sun Jul 03, 2005 6:44 pm

Postby Acrobat on Thu May 15, 2008 6:56 pm

oddson wrote:FYI...

I use a 20 second (at 44.1 KHz) four channel delay in my long-delay projects.

I took the delay alone and made a VST (no controls, no GUI) and it added 19.9 MB to eXT's memory usage compared to the theoretical minimum of 13.4 MB. A null VST (no processing straight-through) made in SynthMaker adds 6 MB so there's very little unaccounted for.


oh yeah infact I was thinking I could ask u too, I remember your long-delay stuff...
I thought the "unaccounted" will be, in my case, also 2 free-running LFOs that should take some more (for the read-256.MEMs and a wavatable OSC with 40 waves x 2048 points... I'll take a look at thee situation...thx... I wondeer what's those 6MB more in your case.. boh! Maybe the "SM shell" itself... :S
User avatar
Acrobat
smaniac
 
Posts: 1660
Joined: Mon Jun 04, 2007 10:50 pm
Location: Roma, Italia

Postby angstrom on Thu May 15, 2008 7:06 pm

yes, I worried about this myself when i started making looper effects, Imagining that the memory usage would cripple any machine ... and I laughed when I calculated the actual usage.

tiny by modern standards.
a looper, some time ago
Image
User avatar
angstrom
smanatic
 
Posts: 724
Joined: Tue Apr 26, 2005 12:46 pm


Return to Sound

Who is online

Users browsing this forum: No registered users and 1 guest