Using sample-based programs (load times)

[Hollow Sun]

There is a common myth spread about Fusion that it is slow to load samples in programs that use them. This is not true - it can be slow if the program uses a lot of samples and/or the samples are very long but, that said, Fusion is a sampler and ALL samplers have to load samples which can never be instantaneous (unless the samples used are minimal and/or very short) - it's a fact of life and a law of physics!

As it happens, Fusion's load times are actually quite swift compared with other samplers which can take several minutes to load just a single program!!!

However, Fusion's sample load function is quite 'intelligent' in that it loads on demand as sounds are selected in the usual way. On most (if not all) other samplers, you must decide in advance which programs you want to use and only once they are loaded can you play them. This usually involves a lot of wading through library to select the sounds and load them. Furthermore, all samplers (hardware or software) have finite memory limits andf when that limit is reached, you are rewarded with an 'INSUFFICIENT MEMORY' error message!

So how does it work on Fusion?

When you select a sample-based program, it loads the samples that program uses. This will take a few seconds depending on the complexity of the program and the size of the samples. When you select another sample-based program, that too will load (another few seconds). and so on. Eventually you might have the samples for maybe 10 or 15 programs loaded.

At this point you can switch between those programs instantly with no load times at all thus you can go from, say, 'CP70' to 'Wurli' to 'Tape Choir' to 'B3' and others instantly.

At some point, however, you will come to the limits of Fusion's memory. However, rather than issue an 'INSUFFICIENT MEMORY' error message, Fusion simply flushes out the first few samples that were loaded to accommodate the new samples. And so on. Of course, the more memory you have installed, the more samples you can have loaded before this happens.

It is impossible to say exactly how many sample-based programs can be 'loaded' because the size of the samples they contain varies greatly. Some programs' samples are just few hundred kb whilst others can be 1 or 2MB. Others (such as detailed pianos, etc.) can be 5 or 6MB ... maybe as much as 10Mb so to ask how many programs can be loaded is a bit like asking "How long is a piece of string?"! Naturally, with the memory expansion board installed, many more can be loaded and available for instant selection.

SAMPLE LOAD TIMES IN A LIVE SITUATION
In the studio, the load times are of no real consequence but in a live situation, even a few seconds load time can be inconvenient, especially in the middle of a song (not really a problem between songs).

To overcome this, it is good practice to 'pre-load' all the sample based programs you will need for the gig before it starts. There are several ways you can achieve this:

* USE THE FAVOURITES FEATURE
By saving all the programs you need for the gig in a favourites bank, once you are set up, simply go through the programs in your favourites to pre-load those program's samples - it'll only take a few minutes at most. You can now switch between those programs instantly during the gig.

* ORGANISE A 'SET' BANK
Using the STORE page, create a new bank (called 'SET' or whatever) and save the programs you need for the gig programs to that bank.

Alternatively, hook your Fusion up to your Mac/PC via USB and organise your programs as you want.

WARNING!!! - not for the uninitiated!!! Arbitrarily moving data around on your Fusion's HD without knowing what you are doing can cause MAJOR problems with sample referencing. If in doubt, don't (or seek advice here)!

However you organise your 'SET bank, prior to the gig, select that bank and just go through the programs to pre-load them. If your live set follows a strict setlist, you can organise the programs in the order they will be used during the gig to make program selection easier.

* SEMI-AUTOMATIC PRE-LOAD
Make up a song and assign all the programs you need to each of the tracks. You don't need to do anything ... you don't have to make up a sequence or set any parameters relating to the programs in the song - you are just using the song as a 'dumping ground' for the programs you want to use in the gig. Save the the sequence.

When you arrive at the gig, simply select that song - it will automatically load all the programs contained in it and will pre-load the samples. Now switch to PROGRAM or MIX mode (whichever you use live) - you will be able to switch between programs instantly because all their samples will be pre-loaded.

TIP: Before you switch your Fusion off to go to the gig, select SONG mode and select your 'pre-load' sequence. Once it's loaded, switch off your Fusion. When you arrive at the gig and switch your Fusion on, that song will be selected automatically and so your samples will pre-load with no intervention on your part!!

If you require more than 32 programs, simply create another song, do the same and select that song as well prior to the gig.

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It goes without saying that for live use, whichever method you use for pre-loading samples prior to the gig, the memory expansion is thoroughly recommended.

[markone]

Good post.

The only caveat I would add is that you can make the Fusion throw a memory error (Looks something like "VEng: Unable to load xxxxxx") if you play a lot in Mix mode.

I don't know the details - gwenhwyfaer can probably explain it, but there are 2 synth engines and they share the DSP load in mix mode. You can end up with it loading the same sound in to both engines, and then not unloading it properly when you pile on more instruments in the mix. (or something along those lines!)

To demonstrate: Here is a sure fire way to make this happen

Load up Mix ROM P8 (MIDI Template)

Go to edit

On Channel 1 change the instrument to the Indiginus Blueridge Guitar
On Channel 2 change the instrument to ROM GM E3 Picked Bass
On Channel 8 change the instrument to the Indiginus Guitar Strums
On Channel 10 change the instrument to Sampleheads Drums

Instant VENG Error on my machine... Every time

Now, actually, I don't mind that it's running out of sample RAM... It's just that it's not doing so very gracefully, (Maybe a message "You have run out of sample RAM, choose a different instrument or use an odd numbered channel" or something would be a much better user experience.

Now in my experience the way it dynamically assigns memory means often once you get to the VENG error state, the only way to clear out RAM is a full reset.

Perhaps an "Unload samples" function would be a more user friendly option.

Generally my experience is, people don't actually mind error messages, providing they are meaningful and there is a graceful and stable way back.

Anyway this little foible aside, providing you don't try to load up a mix with huge samples (These blueridge guitars and that sampleheads kit are pretty big) it isn't something you bump into that often, and I think that sharing stuff between odd and even tracks helps, by sharing the load between voice engines.

Sorry if I haven't explained this very well

[gwenhwyfaer]

The problem there is that you're trying to switch to a program whose samples are larger than the memory the Fusion has left, but it can't deallocate what it's already allocated because those instruments are still in use.

As you say, doing that combination of things does indeed cause a VEng error. However, I found that all I had to do to get out of it was press OK and select a different instrument instead - no reset needed. Admittedly, it might cause problems down the line... but if you get to that situation, the only answer is to use less RAM-intensive programs (perhaps by using the Indiginus samples to create a Guitar Strums Lite? Or by only using the Sampleheadz samples that correspond with the velocity ranges you're actually using?) - but if you go back and select less RAM-intensive programs, you'll be away.

I also tested what happens if you fill up the RAM on both VEngs and then switch from "optimize for polyphony" to "optimize for load time" (the pathological case; at that point the Fusion has to start bailing out samples like mad!) - but again, my Fusion stubbornly refused to crash - it just unloaded the last program in.

The phenomenon you're describing here is that commonly known as "you can't fit a quart in a pint pot" and it does appear that the Fusion designers considered this. The error message could be friendlier, true - but there's nothing else the Fusion can do at that point, other than refuse to load the program in question - which is what it does.

[ajmuso]

Great info from gwen as usual..

I suffered from and investigated the dreaded Veng message..
and fully concur with that it is generaly only a problem when using very large sample based sounds...typicaly the sampleheads kit and the blueridge guitar..

It is most problematic in song mode In theory the fusion should unload enough unused samples from memory to load the next set .

I found a workaround that works almost all the time..

here is what happened to me.

I had a set list of 7 songs, several of which use the sampleheads kit, and one uses the blueridge as well!!, one has 4 instances of Holy grail piano.

going through the set list , I monitor the sample ram being used, and by song 4 both engines are close to 100%..

this is when you will get the Veng error..
now what I used to do is re boot the fusion.. which is not realy an option when performing live!

I found that if you go and change between optimize for polyphony and optimize for load time, this FORCES the fusion to unload and reload its sample ram, this negates the need for a reboot!!. its a tad fiddly i would admit, but better that a reboot!

cheers


Andy

[guydenruyter]

Has anyone de-mystified the secrets regarding memory occupation if you are using the same program various times in a mix or song? I often use the same program (in particular a drum program) e.g. 6 times, different tracks in the same Song. The Fusion seems to load it more than once, but not 6 times. I read somewhere that you can optimise this also by assigning the same program only to e.g. odd or even track numbers.

[gwenhwyfaer]

As far as I know the Fusion will load it once per VEng - so presumably alternate track numbers go to alternate VEngs? (Unless you've switched to "opt.for load time", of course.)

[electrique]

My think off was as follows: Modern hard disk drives have a maximum speed over 30MB/sec. When I load a sample about 60 MB it should take 2 or 3 seconds maximum time. But it takes about 10 seconds or more - what's the reason?
In my opinion it's not the speed of the hard drive. I think, that the hard drive goes only in a mode, which is called PIO in computers. If there would be a DMA-Mode, also big samples wouldn't be a problem - also with small RAM (64 MB).
So it's my heaviest feature request: DMA mode for the hard disc drive. I hope there's no hardware limitation...

[gwenhwyfaer]

I'm pretty sure that DMA vs PIO is a property of the IDE controller, not of the disk drive; and it's basically an artifact of the PC's architecture, where initially it was faster to make the CPU fetch each word in from the hard disk itself. DMA lets the IDE controller dump data directly into memory without going via the CPU, which makes a lot more sense when CPUs are much faster than both memory and IDE interfaces (otherwise your ridiculously fast CPU ends up spending most of its time waiting for its IN and OUT instructions to do something, rather than actually doing the calculations you're paying for). The disk drive doesn't care; it'll just sling data at whatever asks for it as fast as it can. (The disk drive does have different transfer modes, sure, but the fastest ones to use without an excess of interface logic are 12.5Mb/sec and 16.7Mb/sec - more than fast enough to stream off 8 tracks of 44.1kHz audio in 32-bit float format.)

However, when your CPU, memory and disk drive interface work at about the same speed, and your CPU wasn't doing anything else anyway, there's not actually any gain in going to the hassle of arranging DMA - better to go for the simplest thing that works. In any case, before you can consider Direct Memory Access, you need to ensure that your IDE controller can actually access said memory directly; and the 32067s can't even talk to each other's memory directly, let alone allowing an IDE controller to get a look-in.

Also note that in Program mode, the samples are loaded into each 32067 in sequence, which immediately doubles load time - hence the option to turn one of them off being called "optimise for load time", even though it only decreases load time in Program mode. So if 60Mb loads in 5 seconds, that's equivalent to 12Mb/sec - which is pretty good for a disk drive's sustained transfer rate, especially a 5400rpm drive.

In short - DMA probably isn't possible, and in any case probably wouldn't make any difference; chances are the samples themselves are already coming off the hard drive as fast as they can. If you want better performance, get a faster hard drive.

However, one of the advantages of PIO (in PC terms) is that you can process data as it comes in from the hard drive without buffering it first. So even without DMA, the processor could, in theory, send sample data to both 32067s in parallel, a word at a time, rather than one after the other. That might be quite a nice optimisation; and whilst we're at it, we could get rid of the misnamed and newly-redundant "optimise for polyphony/load time" option...

[neomad]

Impressive explanation gwen. If I understand correctly, the actual 80gb hd in some fusions have the same effects as 40gb 5400 rpm ?

Regards.