Near the edge of maximum dsp

Casper · Post by **Casper** » Fri Aug 12, 2005 6:57 am

Hello people,

I just found out that there is a difference in DSP load when switching to e.g. 16 voices.
(powerpulsar)
I first loaded a synth , then I just changed number of voices from 1 to 16.
And wham there came the max dsp message.
So I just wondered and tried changing from 1 to 8 , all ok . Then I started just adding one voice each step and found myself ending on 16 voices.

So my tip realy is , if you want the maximum out of a synth , try stepping towards that number in little steps. Instead of entering e.g. 16 rightaway.

Cheers,
Casper

wayne · Post by **wayne** » Fri Aug 12, 2005 7:53 am

Makes sense, somehow. -Astroman, why is that?

astroman · Post by **astroman** » Fri Aug 12, 2005 12:10 pm

tnx for invitation

I dunno the algorithm how the modules are distributed over DSPs, but it must be at least a bit smart (considering how many 'elements' make up a single module).

Obviously it helps if the chunks are smaller, so Caspers observation makes sense.
The intermediate steps could also force some automatic optimization, similiar to the message that pops up in overload situations.

cheers, tom

at0m · Post by **at0m** » Fri Aug 12, 2005 12:12 pm

There's no relocation or load balancing when something is added afaik.

blazesboylan · Post by **blazesboylan** » Fri Aug 12, 2005 12:43 pm

You'll find that often you can add elements to a project that don't max out the DSP, but then when you re-load the project, you're screwed!

Post by **hubird** » Fri Aug 12, 2005 2:36 pm

must be pure character then

darkrezin · Post by **darkrezin** » Fri Aug 12, 2005 4:17 pm

It's more analog this way...

Post by **hubird** » Fri Aug 12, 2005 5:32 pm

automaticly better music also...

Lima · Post by **Lima** » Sat Aug 13, 2005 3:39 am

Hi, I've got another experience (similar in some things):
One day I've done a test to know the pci capacity limit. So I've setted 48 KHz (the frequence I usually use) and I've loaded some masterverbs. The limit was reached with 12 masterverbs (pulsar1 + pulsar2).
then I've unloaded 1 masterverb and the message of "pci capacity limit" reappers.
So I've continued unloading masterverbs until there was 9 loaded.
I've noticed that with 11 masterverbs, and before loading the 12th, all worked right (the masterverbs work correclty).

Casper · Post by **Casper** » Sat Aug 13, 2005 4:00 am

"You'll find that often you can add elements to a project that don't max out the DSP, but then when you re-load the project, you're screwed!"

Yes , I got this too once. Wasn't so funny though. Since then I'm saving the projects on critical points under a different name.

But ok , this tip isn't realy worth anything . Only for those who want to know how much voices a certain synth can take.
That's why I stumbled upon it. I was just testing a SDK synth.

cheers,
Casper

blazesboylan · Post by **blazesboylan** » Sun Aug 14, 2005 1:07 am

On 2005-08-13 05:00, Casper wrote:
Yes , I got this too once.

For me it happens all the time...

wayne · Post by **wayne** » Sun Aug 14, 2005 6:28 am

On 2005-08-13 05:00, Casper wrote:

But ok , this tip isn't realy worth anything

- nah, this is a good thread.

dawman · Post by **dawman** » Sun Aug 14, 2005 10:29 am

I know that's a good thread. I was wondering since I use an external Lexicon through sp/dif'd i/o's, it's only 1 instance of reverb at a time. I should be able to use an Alesis Q20 through ADAT i/o's, and use their excellant sounding plate algorhythim, before I purchase it I was hoping someone could explain how much, and if any DSP draw external FX use, and am I retarded for not using a Scope reverb? From what I've learned about computer programs in general is that I push them when I'm programming, and when I perform, I only want to run stably at 50%. Seems the advice I've been given has all been good. Whatcha think Astro?

<font size=-1>[ This Message was edited by: scope4live on 2005-08-14 11:30 ]</font>

blazesboylan · Post by **blazesboylan** » Sun Aug 14, 2005 11:44 am

Well I'm not Astroman, but while Tom's sleeping I'll insert my 2 cents.

I don't have any exact numbers, but your "50% rule" seems pretty optimal to me on SCOPE. When the little yellow bar hits 75-90%, that's when I start getting real stability problems -- DSP max-outs that lead to 1/2 hour of "do you wish to optimize?" messages, or, in some cases, even crashes. 50% DSP usage is smooth sailing, though. Though I suspect that the "optimal" DSP usage is higher for a single-board system.

On the reverb issue, I personally prefer outboard effects verbs (even some cheap ones) to the standard SCOPE ones, by a long shot. However for the other effects -- chorus, flanger, delay -- I think SFP is great. Those effects aren't as DSP-hungry as the verb plugins, either.

The Masterverb etc are way more DSP-hungry than routing through ADAT ins and outs. In fact the hardware I/O are about the cheapest DSP modules in the whole system, IME.

So choosing an outboard reverb or two to use with SCOPE is a good idea in my books!

(I considered recently bidding on EBay for an 8 foot high plate verb, the EMT 140, to use as a "plugout" with SFP. But even though it was being auctioned for stupidly cheap, I couldn't really afford the unit itself, let alone the shipping. Still, it made be drool all over myself!

)

dawman · Post by **dawman** » Sun Aug 14, 2005 2:51 pm

I'm glad that you share my ears. I use Celmos Tape Sim because it's replaced my PCM42,and PCM41.But my PCM70, can only be replaced with the MPX550.I just don't hear a replacement in Scope. Besides, too much DSP usage for something that doesn't compare seems like a waste.Where as for modulation FX Scope excells.I swear Celmo must have the same gear I have, his Phaza, has replaced my Maestro pedal also.By the way I think I'm going to purchase another board just for the extra headroom, and outputs. Probably a Scope Project, because I think the platform is changing to external hardware, like the ASB's. I have my name down for the next available Prophet ASB, I just hope they modeled it after the first series which used the SSM chips instead of the Curtis ( CES )ones.I'm not sure many people had the privelage of playing the "0" series, but I am an ancient warrior of the keys.I opted for the OBX-a at the time. But now I have an Oberheim XPander, and the Prophet will be a welcome addition to my rig. Funny I thought by now I'd have all the toys I need.I guess I'll be half hardware, half software, and 2 years from now I'll still find a reason to upgrade. I'd better face reality and admit I'm a habitual synth-head addict, who will justify his spending year after year. Have been playing live since 1969 (7th Grade ), but I love it so.

blazesboylan · Post by **blazesboylan** » Sun Aug 14, 2005 5:15 pm

On 2005-08-14 15:51, scope4live wrote:
Funny I thought by now I'd have all the toys I need.

And what the hey, why not spend money on what you love?

dawman · Post by **dawman** » Sun Aug 14, 2005 6:59 pm

Speaking of what I love.Just finished sequencing 15 Emerson,Lake,& Palmer songs. That's how I practice up for the gig.Once you can play through with no mistakes, you got it. My QX-1 still works flawlessley. The scope card does all the mixing of GS3, and Scope instruments. Mr.Arkadin of PlanetZ, made a nice C3 preset on the B2003, which I route out to a Pro3T rotary cabinet on full stop. GS3, plays the Grand Piano, Minimax actually does the Moog Modular sound quite acuratelly. 10 years ago I could not have possibly set up all the gear and have such good rehersals as I do now. You gotta love it.Nice chatting to you fellow pulsarian.

astroman · Post by **astroman** » Mon Aug 15, 2005 8:38 am

nice setups of you both...

imho SFP stability is a very individual case - and I doubt that the obvious (heavy load) is main culprit.
the system is incredibly complex by default - it can do almost all and everything, so if one just happens to summon the wrong components it may refuse to work as intended.

I have some 'regular' flaws that I just ignore because the overall useability is too great compared to an occasional hick-up

none of them is related to DSP max load

I rarely switch projects, I have a 'preferred' current one to which I add one or two synths or heavy-weight fx (like A100 or Echo3), because 8 DSPs force some restrictions anyway.

the system reliably hangs on loading a device after a project ran > half an hour (specially idle) - to avoid this I simply reload it in advance.

2nd glitch is that a synth doesn't respond to key tracking anymore after it has been with a lot of patch changes.
this applies only (and reliably) to patches with portamento on.
Switching portamento off brings key tracking back immediately.
To avoid this I reload the synth - experienced with CWA and 3rd party devices.

since both errors are absolutely predictable one could easily setup a 'live' system in a way to avoid those situations at all.
in this context I'd rather assume that a certain 'error rate' is specific to one's setup and preferences of work, not to load rate of DSPs.
yet in a 'live' situation the 50% rule isn't such a bad idea, as those setups usually reload faster when things get messed

cheers, Tom

blazesboylan · Post by **blazesboylan** » Mon Aug 15, 2005 4:13 pm

the system reliably hangs on loading a device after a project ran > half an hour (specially idle)

I guess I'm veering off-topic, but I agree that idle SFP == problem time. I can use SFP for 18 hours straight, no blips. But then if I leave it idle for 18 hours (even if it's receiving a MIDI signal every minute), then when I come back and touch the user interface, it's unusable. Audio and MIDI still work, mind you -- but the GUI is kaput. The only solution is "kill -9" (or whatever it's called in Windoze speak

).

valis · Post by **valis** » Mon Aug 15, 2005 6:04 pm

When I used the Creamware cards in my primary system (Dual 1.8ghz/400mhz ram) RedMuze pointed me at the 'reset board if idle' setting under the settings tab in the "Creamware Pulsar(2) properties" window. Once I unchecked that I never again had a 'hung' GUI or a 'crash' when inserting a new dsp plugin. This system was ACPI enabled (not sure if that makes a difference).

Now that the cards sit in an ancient bx-based P3 with 100mhz ram I find I have to close SFP between sessions. Reset board if idle seems to have no effect. This system has NO APIC 2.0 controller and is installed with Standard PC.

Really no big deal once I learned to close SFP.exe, but I thought I'd add my 2 cents just in case a pattern emerges here.

<font size=-1>[ This Message was edited by: valis on 2005-08-15 19:05 ]</font>