DFD, RAM, and CPU

Just thought I'd post this here for anyone that might find it helpful.

One area that seems to cause some confusion when working with sampler software like Kontakt or a virtual instrument like VDL2 is the DFD extension (direct from disk) and RAM requirements.

First as a general rule, your computer will access sample data MUCH faster from RAM than it will from your hard drive. Since most people don't have boatloads of RAM, they can install NI's [url=https://www.tapspace.com/updates]DFD Extension[/url] which basically allows sample data to be streamed from the hard drive by creating [b]buffers[/b]. These buffers basically load a small portion of each sample to memory so they can be instantly accessed when they're called upon. Once they're called upon, DFD will then begin the ";stream"; from the hard drive so that sample can continue playing back. This DFD streaming process will work best if the sample data is being streamed from a fast hard drive (7200RPM or greater).

Your CPU is the ";traffic cop"; for all of this. As long as it's fast enough to maintain the buffer playback as well as the streaming playback, everything will move along smoothly. If your music contains many fast attacks (like drumline parts) and/or is very polyphonic, that's what will tax the system most.

For the reasons described above, faster CPUs are always most desireable. If you have enough RAM to load all your samples without DFD, performance will be best. If you do need to rely on DFD, it's highly recommended to have a fast hard drive where you host your samples. Many users will run the software/operating system from their ";main"; hard drive while using a second hard drive for streaming/bouncing audio, etc.

Since Virtual Drumline 2 is often used in conjunction with notation programs, keep in mind that in addition to the technical process described above, your computer is also being asked to allocate some of its resources to running the notation program itself. And since marching band/corps music can tend to be quite polyphonic, you can see why it's preferred to use a system with a healthy collection of resources.
If you look at a VDL 2.5 instrument when it's loaded into KP2, you'll see there's a ";Release"; knob. You can manually lower this knob with your mouse, but if you're working within Sibelius, it's much more efficient to control the knob with MIDI messages. As you'll see in the VDL User Guide, this knob is assigned to MIDI Controller #20. So by typing this text into your score...

[i]~C20,1[/i]

...you're essentially lowering that knob all the way down. You can do this at any value between 1 and 127 and it's done on an instrument-specific basis. In some instruments, lowering it all the way down will give less realistic results, so you may have to experiment a little. I'd start by experimenting with instruments that have a longer release tail such as vibraphones, glocks, cymbals, gongs, etc.
Jim,

I have ";swiss cheese"; holes in my knowledge of utilizing VDL 2.5.  To lower the release time, is that something I can apply to a specific instance of playback?  Would I do that by lowering this value prior to notation entry?

This is all very useful reading.

David Vita
Forgot to mention that one!  That also was an amazing difference.  You'd be suprised the sustain on everything and how it can effect the performance. 
Some good tips Chris.

Another one that people often don't realize is that you can reduce the release tails on long sustaining instruments (like Vibes, glock, timpani, chimes, etc.). In the VDL interface, you'll see a ";Release"; knob (which, by the way, can also be automated with MIDI controller #20). During fast passages where there's a lot of polyphony build up, you'd be amazed at how much lowering this knob can improve your performance!
Just as a note here, I've had difficulty running VDL2 on my laptop with full sets.  (Powerbook G4, 2.66 ghz (I think), 2 gigs ram, 120 gig hd)

I wrote a chart last year - Glock, Xylo, Vibes, Marimba 1,2,3, Timp, Aux 1, Chimes, Snare, Bass, Tenors and, when fully entered with dynamics, etc would have difficulty playing back at 100%.

Perhaps it's because I had another program running, or due to a quantity of Widgets, but I'm not sure.  Nonetheless, a real helpful item has been recording to external HDs and shutting off Widgets when doing intensive Finale work.
Very true Justin. Thanks for chiming in with your real-world experience.

This is probably the main thing laptop users need to realize. Most laptops don't come default with 7200RPM hard drives, though you can usually configure this as an add-on. Since DFD is an important part of using Kontakt/Kontakt Player, I think it's well worth the performance boost. Especially if you plan to run more than 5 (or so) voices at the same time.
I have a Mac Pro with two 2.6GHz dual-core xeons, a serial ATA 7200RPM HD, and 2 gigs of ram.  I also have a Powerbook laptop with a 2.6GHz G4 processor, an IDE 5400RPM HD, and 2 gigs of ram.  The difference between the two is absolutely unreal.  You need ram to be able to handle the library-in-memory, but a zippy processor and fast HD (especially if utilizing DFD) makes mountains of difference.
hi guys

what set ups do you use or would you reccommend in terms of RAM, processor etc, having just ordered a copy, I know have to upgrade my PC quite heavily Im aiming for 2 Gig Ram and hoefully the new dual core processors (2x 3.2ghz = 6.4).

Im not really a computer technical person so would really appreciate the advice from any of you as it would be interesting to hear from Mac and PC users with diffeent levels of equipment etc and useful to hear from those of you who just have it running from a standard PC.

Tom Pat
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