[LAU] Discussion: Future CPU-technology vs. realtime audio?

[Len Ovens]

On Wed, 27 Jan 2021, david wrote:

> Intel doesn't run at top speed "forever". Fastest clock I've got from my 
> nominal 5GHz-max i9 in my Dell XPS 15 is 4.7GHz. Intel runs clock speed 
> until thermals say "Slow down." If you're talking about a laptop, the

Yes heat is the limit. My (older now) i5 will run at rated speed forever 
and in fact can run at .2Ghz over that without triggering heat throttling.

> specific laptop's ability to dissipate heat is the controlling factor. 
> I'm not sure that Intel thermal control is anywhere within reach of BIOS 
> and OS software.

I would tend to agree with the engineering, but it is possible to set the 
top speed below rated if heat dissapation is not up to full speed. My 
steady state device temperature while building Ardour lets me know when I 
need to clean the dust out... after about 10min of all cores at 100% the 
temperature reaches a top temperature and sits there with no speed drop. 
If I have boost turned on the speed seems to sit .2 Ghz higher.

>From helping people trouble shoot newer HW than mine, it seems newer HW 
(firmware?) does a better job handing out irqs with none of them being 
doubled up. However, it seems harder to prioritize a USB device above 
other USB devices... maybe it matters less for some systems.

I got an older firewire device this past year (Audiofire 12) and while use 
under the new ALSA fw modules has been poor (256 frame size minimum), Used 
with the ffado modules... it seems to shine better than anything I have 
seen... it is true that at 16/2 (I thought it needed /3 but /2 works) the 
DSP is up at 25% with just jack running (with pulse bridging), there are 
no xruns unless runninig for days when there may be one xrun. This 
is better than my old ice1712 PCI card which can also run at 16/2 but not 
without the odd xrun. USB? I don't have a "good" USB device... but I have 
not heard great things about even the best of them. (my $1 USB 1.1 audio 
devices will not run below 64/2 without locking jack up)

The audio community lost out with the "everything is USB" systems of 
today. I can't afford to try the PCIe cards from AudioScience or the like 
to compare. I hope the next gen is better.


--
Len Ovens
www.ovenwerks.net