Re: [LAU] Small instrument hardware module

On 22/10/14 04:15, Len Ovens wrote:
> On Tue, 21 Oct 2014, Harry van Haaren wrote:
>
>> Hey all,
>> I have a HDA ( cat /proc/interrupts tells me so anyway: snd_hda_intel ).
>> Its my built-in laptop soundcard, and it works pretty well, down to
>> about 44.1kHz, -p128
>> -n3. That's ~8ms, which is acceptable IMO.
>>
>> I've read on mailing list / internet somewhere* that spec for the HDA
>> is pretty
>> open-to-interpretation, so I think the exact hardware / chipset would
>> need to be tested
>> to get true results.
>
This is also what I was lead to believe. snd_hda_intel covers a fair
range of different chips, each of which has its own characteristics and
so there is no single answer to the original question. Pretty sure both
my last two laptops were reported as snd_hda_intel and know they were
definitely different sound chips! (Although offhand couldn't tell you
what...)

"Like AC'97, HD Audio is a specification that defines the architecture,
link frame format, and programming interfaces used by the controller on
the PCI bus <http://en.wikipedia.org/wiki/Conventional_PCI> and by the
codec on the other side of the link. Implementations of the host
controller are available from at least Intel
<http://en.wikipedia.org/wiki/Intel>, Nvidia
<http://en.wikipedia.org/wiki/Nvidia>, and AMD
<http://en.wikipedia.org/wiki/AMD>."
<http://en.wikipedia.org/wiki/Intel_High_Definition_Audio#cite_note-sb600-7>
[1]

> I have gotten 48k -p64 -n3 on mine. Jack will crash if I try -p64 -n2,
> but -p128 -n2 works.
> From my reading, HDA is (like AC97) more of a bus spec than a sound
> spec. It seems to deal with connecting the sound from the HW to the
> internal bus. The HDA bus runs at 48K (like AC97) but does not expect
> the HW to be 48k (as AC97 did) and has methods for transporting audio
> with other sample rates than 48K.
>
> In my opinion, 128/2 is just on the edge of useful for live (guitarix
> for example) use. 256/2 is annoying already. (No I do not play play
> really fast or anything like that)
>

With no careful tuning I run my internal at 48k -p128 -n3 and get rare
xruns, mostly if I have my wifi turned on but still the very occasional
one otherwise.

Not sure if there is a mistake on the page or if my laptop actually has
both of these for something?? [2]
Intel 7 Series/C210 Series Chipset Family High Definition Audio
Controller
<http://www.ubuntu.com/certification/catalog/component/pci/8086%3A1e20/>
Intel Panther Point High Definition Audio Controller
<http://www.ubuntu.com/certification/catalog/component/pci/8086%3A1e20/>

[1] http://en.wikipedia.org/wiki/Intel_High_Definition_Audio
[2] http://www.ubuntu.com/certification/hardware/201206-11273/components/

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Received on Wed Oct 22 08:15:01 2014