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

[david]

On 1/27/21 8:41 PM, Len Ovens wrote:
> 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.
>
Heat *dissipation* is the limit. Laptops are very poor at heat 
dissipation. An over-packed compact desk case can have problems. One 
benefit to the old-school full height case. ;)
>> 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.
>
The only way my i9 will hit 5GHz, according to Intel specs, is if it's 
only using 1 core.
> 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.
>
Could be, I don't know. Particularly when you start mixing USB1, USB2, 
USB3, USB3.2/USB-C into things.
> 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)
>
My USB device runs at 64/3. I didn't have any JACK lockups at 64/2, but 
got lots of xruns.
> 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. 
I agree with that. I only hope the USB-C/3.2 doesn't mean a barrage of 
proprietary drivers.

-- 
David W. Jones
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