Re: DICE II Firewire Driver Settings

philicorda wrote:

The safe modes are to mitigate problems when other drivers (for video, usb etc) spend too much time in a DPC call, and the kernel cannot run the soundcard driver in time for it to service the audio buffers.

Misnamed, I think, but that sounds like a reasonable thing to do to help people like me who don't know what a DPC call is and thinks a kernel is where popcorn starts.

They solve this by using larger kernel side buffers = increased latency. The larger buffer size means there can be a longer delay before the driver runs.
I imagine the latency gets longer with the higher safe modes.

So, some other driver on your system is not real time safe, or else perhaps a driver has made a non preemptable system call that must be carried out before another driver can run.

So, is there anything I can do about this that will make it work better other than to slow it down? I'll check out that Gearslutz reference to see if there's anything I can use there. I may have actually run across that in my Googling, but most of what I saw about the DICE was about the Alesis I/O thing so I passed it up. The Zed is probably too new for anyone to start talking about it yet.

The difference between the kernel side buffers and the normal audio ones is that the audio buffers affect how many samples are in each buffer that is sent to the soundcard, thus a larger buffer means less interrupts so each interrupt is more likely to be serviced in time. A larger driver kernel buffer affects how long another driver can spinlock before the sound card driver must run.

I thought that Firewire was supposed to mitigate problems like that because of its smarts to keep data flowing. At least that's one of the arguments that people use in the Firewire vs. USB2 wars.

I had some initial problems with my DICEII based Presonus Firestudio. Not working well at low latency and the occasional glitch. Getting a new TI PCI firewire card improved matters. (And a VIA one too that did not work so well.)

Yeah, that's one of the standard Firewire audio fix-its. Whatever Firewire I/O card you have, get something different. <g> It's getting harder to tell what chipset a particular card uses though. They used to put that info on the box sometimes, now you don't always even get a box. And the hardware manufacturers don't necessarily use the same parts this year that they used last year. So if someone who bought a Brand A card a couple of years back and found (by checking it in the Windows Device Manager) that it had a TI chip tells you to get one like it, unless you buy one just as old, there's no guarantee that you'll get the chip you're looking for.

When I got the Mackie Onyx mixer card, my first Firewire audio deveice, I didn't have a Firewire card in any of my computers. My laptop was the most powerful one at the time, so I got a PCMCIA adapter for it. Got clicks and pops, so I exchanged it for a different brand, and then a third one, until I finally found the noises were related to the network card. A new driver for that fixed the problem, and I suspect that any of the Firewire cards I had would have worked fine.


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