multi-console and realtime audio - up and running.

[James v. Z. <ja...@dv...>]

It seems the awnser was in the question. After retrying using an nv open
source driver for the PCI console, I have a wholly operational 2 console
realtime audio workstation.

As the open source nv driver crashes on me whenever I try it for
multi-console, I have not yet tried three or four consoles. Fedora's
x.org build has been like this for awhile. I understand others have nv
driver running multi-console; I have retained the nvidia driver on my
AGP console and this works for me.

Throwing a relatively heavy load at it, audio-wise and happy with the
result. Pity the PCI console can't handle opengl, but....I have the
multi-console workstation I was working for.

J

On Wed, 2006-05-31 at 22:17 +1000, James van Zeeland wrote:

> Renicing jackd to -20 and all X.org servers to 19 helps, but does not
> solve the issue. I can now allow the terminals to be logged in,
> expecting more than a few jack xruns, but the PCI consoles must be
> abandoned when the time comes to record, as we cannot tolerate audio
> glitches in the recording.
>=20
> With the RRT kernel (planetccrma rt+faketty+nVidia drivers) using just
> an AGP console, I get perfect performance - no xruns. at all until I
> finally stopped jackd; several hours. Realtime monitoring etc turned on
> the whole time, near perfect all 'round, I say.
>=20
> I thought I'd gotten a good combo of IRQ's for this - are there other
> suggestions out there? Anything else I can tune?
>=20
> J
>=20
> On Thu, 2006-05-25 at 18:19 +0200, Zoltan Boszormenyi wrote:
> > Hi,
> >=20
> > James van Zeeland =C3=ADrta:
> > > Hi all.
> > >
> > > I have created a standalone faketty0.05_hijackled patch downloadabl=
e
> > > from my homepage; initially against 2.6.16.9, but it should apply
> > > broadly.
> > >
> > > http://members.westnet.com.au/vanzeeland
> > >
> > > I have been getting excellent results with realtime multimedia on a=
 3Ghz
> > > P4 - I am hoping to get realtime multi-console happenning, but ther=
e are
> > > some catches. While it works fine for most applications, indeed, it=
's
> > > overall latencies are down considerably, PCI video kills the mix; a
> > > multi-console machine will be good for realtime audio only if one u=
ses
> > > the AGP console only, logging out all other consoles and leaving th=
em
> > > alone.
> > >
> > > Any PCI console activity causes audible audio glitches. Bear in min=
d
> > > that we are recording 32bit audio files from 24bit sources at 96Khz=
, so
> > > there is a significantly higher load than using 16bit audio. over 4=
x.
> > >
> > > I am investigating ways to drastic lower the realtime performance i=
mpact
> > > from PCI video cards.
> > > Is anyone aware of methods, kernel tweaks or tools that may assist =
in
> > > altering the PCI performance of the PCI video?
> > >  =20
> >=20
> > Using "nice" or "renice" gives you the wanted effect.
> > It clearly shows on my PCI card if I start "supertux",
> > it skips very often but I can continue compiling on
> > the other console... On my system, the PCI VGA
> > blocks or throttles the PCI IDE in a similar way.
> >=20
> > > We effectively don't care about video performance on pci consoles. =
If it
> > > means they're noticably slower but audio operates in realtime, that=
's
> > > great.
> > >
> > > Does anyone have any info on how a USB console might load the syste=
m?
> > >  =20
> >=20
> > USB used to have a CPU hog, you have to test recent kernels.
> >=20
> > > I will be posting realtime kernels with faketty included soon,  fol=
lowed
> > > by a more 'vanilla' kernel sometime over the next week or tso.
> > >
> > > Apart from the audio glitches that you may not see or care about ou=
tside
> > > of pro-audio usage, the realtime kernels provide excellent desktop
> > > interactivity.
> > >
> > > J
> > >  =20
> >=20
> > For a longer term solution, have you considered the following mainboa=
rds?
> > These two below are consumer-grade boards one can buy in the near fut=
ure.
> >=20
> > Gigabyte GA-G1975X, 2x PCIe x16 physical slots, 2x PCIe x4 physical
> > open ended slots, also usable with x16 cards (of these two, one is x1=
,
> > the other is x4 but x2 is the x1 slot is used)
> >=20
> > Gigabyte GA-M59SLI-S5 Board, 3x PCIe x16 physical slots,
> > one of them is x4.
> >=20
> > Workstation mainboard you can buy today:
> > Supermicro A+ *H8DCE, ***2 PCI-e x16 slots, 2 PCI-e x4 slots (x8 phys=
ical)
> >=20
> > The nice thing about PCIe is that any card can work in any slot,
> > you just have to be able to plug them together. The card and the
> > slot controller negotiate the common wiring and use the highest
> > speed both can use. That means that one can cut the end of the slot
> > so an x16 card can be used in any lower grade slot, as Gigabyte
> > proved it with GA-G1975X.
> >=20
> > Best regards,
> > Zolt=C3=A1n b=C3=B6sz=C3=B6rm=C3=A9nyi
> >=20
> >=20
> >=20
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642
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--=20
James van Zeeland <ja...@dv...>