Fathom Synth Development Thread

[FathomSynth]

All speed tests were performed with Intel AVX2

Wave Draw Oscillator, Polyphony 8, Detune Voices 8, Total Voices 64:
OFF CPU 35%
AVX CPU 06% = X6

Metamorphic Oscillator, Polyphony 8, Detune Voices 8, Total Voices 64:
OFF CPU 42%
AVX CPU 03% = X14

[plexuss]

this thread changes titles so often I have no idea what product it is any more....

Plus there are currently 306 pages to wade through, most of which arent relevant anymore

Yeah. It's called the internet. That's part of the purpose of it.

[yellowmix]

There's a search feature that can look just at this thread if you're looking for something specific. You don't have to wade through anything. It's a good way of tracking the history of development.

Though Seaweed could get their own forum here if they want, but since they have their own official forums it makes sense to only have one "outpost" thread here.

[zzz00m]

All speed tests were performed with Intel AVX2

Wave Draw Oscillator, Polyphony 8, Detune Voices 8, Total Voices 64:
OFF CPU 35%
AVX CPU 06% = X6

Metamorphic Oscillator, Polyphony 8, Detune Voices 8, Total Voices 64:
OFF CPU 42%
AVX CPU 03% = X14

Thanks for that info!

It seems that Intel added the AVX2 instruction to the 4th Gen (Haswell) Intel Core chips. Which were produced from 2013-2015.

The original AVX was introduced in the 2nd Gen (Sandy Bridge) Intel Core in 2010, and continued with the 3rd Gen (Ivy Bridge).

I realize that those 2nd/3rd Gen Intel Core CPUs are getting a bit old now, but some of us are still running them.

You mentioned previously that you could add AVX without too much trouble, once you had implemented the AVX2.

Are you still planning to do so?

[FathomSynth]

I just checked the Intel instruction list and I'm not even sure I'm using any of the AVX2 exclusive instructions, so I might even be able to make the first release AVX1 compatable.

I have made a note to check this before the release.

[zzz00m]

I just checked the Intel instruction list and I'm not even sure I'm using any of the AVX2 exclusive instructions, so I might even be able to make the first release AVX1 compatable.

I have made a note to check this before the release.

Thanks!!!

[kylie]

The original AVX was introduced in the 2nd Gen (Sandy Bridge) Intel Core in 2010, and continued with the 3rd Gen (Ivy Bridge).

I realize that those 2nd/3rd Gen Intel Core CPUs are getting a bit old now, but some of us are still running them.

I just realized that my Sandy Bridge EPs aren't even discontinued like most of their generation (status is "Launched"), according to ark.intel.com...

[iuyj]

Why fathom so RAM hungry, after load one patch and it could it eat about 1 GB easily.
Also is it possible to disable spectrum in signal flow view?

[FathomSynth]

Please read the manual on memory management, you can reduce it by making the buffers smaller and setting it to unload the gui memory when it is closed.

Yes you can disable the spectrum in the main view on the front panel by setting Panel Mode to No Overlay.

[iuyj]

Panel Mode not available in mono edition?

[rollasoc]

I just checked the Intel instruction list and I'm not even sure I'm using any of the AVX2 exclusive instructions, so I might even be able to make the first release AVX1 compatable.

I have made a note to check this before the release.

+1 for AVX1, given I have a 2011 processor!

[FathomSynth]

Turning off the spectrum overlay in the main view is available in mono.

On the very front page of the interface on the bottom panel is a dial on the far right called "Panel Mode".
Turn it to the second position which is "No Overlay".
This will prevent it from filling the main view with the spectral graph during play.

[iuyj]

Thank you, I like sound of Fathom, but it requires many resources, have you plan to optimize the synth? Serum working super fast on my pc.

[Buckster]

Thats some very impressive cpu improvements indeed - fantastic achievement. CPU usage is only thing that prevents me using Fathom as much as I'd like currently

I wasn't sure if my 1225v3 Xeon had AVX2 we quite old - 2013 but checked and even the xeons that old do. Makes sense as Massive X works fine

[FathomSynth]

Fathom 3.0 will include Fifth Order Lagrange Polynomial buffer interpolation, which will provide an insane level of audio quality. Here are some diagrams of both the concept and actual spectrum captures.

The function diagrams were produced by applying the interpolation algorithm to envelope points which graphs the actual curve used in audio buffer interpolation but larger.

Linear Interpolation

Spline1.png

Third Order Polynomial Interpolation

Spline3.png

Fifth Order Polynomial Interpolation

Spline5.png

The following spectrums are captured from Fathom for a small audio buffers of 2048 samples which was intentionally chosen to expose noise in the high frequency spectrum produced by slight errors in reading between buffer samples without perfect interpolation.

No Interpolation

Spline Spectrum None.png

Linear Interpolation

Spline Spectrum Linear.png

Third Order Polynomial Spline Interpolation

Spline Spectrum 3.png

Fifth Order Lagrange Polynomial Spline Interpolation

Spline Spectrum 5.png

This is the normal spectrum for Fathom's 16384 sample buffer oscillator with the existing third order polynomial interpolation:

16K Buffer Third Order Interpolation

Spline Spectrum 3 16K.png

Fifth Order Lagrange Polynomial Interpolation quality is so high quality that the spectrum is cleaner using it on a buffer with only 1024 samples than on a 16,000 samples buffer using third order interpolation.

The noise floor is 170 dB on a 15 dB oscillator volume which is a difference of 155 dB or noise of one part in 50 Million.

The Fifth Order Lagrange Interpolation will be available in Fathom 3.0