EXS 24 Logic Sampler Users Group

Murray McDowall wrote:
> Do you use the 32 bit sample storage option for EXS24?
>
> On a big drum
> kit like the Stereo Drums this can make a huge difference to the amount of
> CPU resources consumed.

Sorry I have to disagree on that - well, not exactly disagree, but it
actually doesn't exactly have to do with the number or size of samples but
with the other things you described. The EXS has to convert 16 or 24 bit
samples to 32bit float for all processing in case you choose the "original"
option. This will use additional CPU cycles. But then, otoh you're right
again because a higher number of samples usually needs more processing.
Drums might not be such a good example though as you hardly play 8 note
polyphonic voicings with them. Also, very often on drums the EXS won't have
to do any transpositions which is one of the things which still tax the CPU
a lot - you can crossprove that by setting up an EXS set with a single
waveform with a root key of let's say C1 and play some chords in the higher
registers, CPU performance will immediately jump up. With 32bit float the
CPU useage will be pretty much less.
The most important thing on huge sets is that you will (obviously) loose
more RAM (1/2 when using 16bit samples, 1/3 on 24bit ones). The increase of
CPU power however is noticeable - therefore it makes perfect sense to switch
to 32bit float, especially in these days where RAM is dead cheap.

> Of course the other things you can do are A) minimize the number of voices
> for the instruments you are using and B) turn off filters which gobble CPU
> cycles.

Yes, on the Xtreme Analog CD I found quite some patches that don't sound any
different with the filter switched on or off

Arvid Solvang wrote:
> I didn't do this and I have never heard of that option.
>
> How much ram is "a lot"?
> I have 512Mb

For most situations this should be pretty much enough - but of course you
could do the maths by yourself in case you have a RAM checker.
Recently I had to pull out one of my two 256MB chips (the new one still
isn't in) but I experienced no problems, even with more complexed songs
where I used some rather large string samples.

> Is this a prefernece that goes for all songs or is it songbased?

It's a global preference. Maybe songbased would be better - but as said
above, in these days you just pack your computer with RAM and never ever
have to think about it again.

> Is there any reason to not use it in 32 bit if you have lots of ram?

No, not at all. The EXS will just convert to 32bit and be happy about that.
You too because on some sets the CPU performance will drop significantly.

Regards,
Sascha