Good info! Thanks! I'm doing something similar and although It didn't affect WSJT-X it did cause issues with my loggin software trying to do lookups.
On Tue, Jan 29, 2019 at 1:04 AM Mike Lewis <k7...@hotmail.com> wrote: > You have probably seen my earlier posts tracking down the cause of lost > decode cycles, or more often, decoding just completely stops on a new HP > laptop when CPU utilization is < 10%. Above that all is fine. This is on > a new 8th gen Core i5 8265U, Intel UHD620 GPU, 8GB RAM, 256GB SSD, and > 1366x720 display. USB audio and internal Realtek sound devices. Laptop > lid open or closed, no matter. > > > > The final solution here was to set the Display timeout to Never. I > normally only RDP to this machine and the lid is always closed, so the > display would normally shut off for that reason. Never thought a timer > setting would still matter, but it does. > > > > After many long hours (over 5 weeks’ worth) of testing and experimenting > with every setting and program combination you could imagine, debug builds, > changing C states, latency analysis, I noticed a loose correlation with > decoding usually working the first several minutes after a reboot before > coming to an end and a display setting. The “Turn Off Display after XX > minutes” option in the Advanced Power Options menu. I am thinking that the > display (and external graphics HDMI connector) is always forced on after a > reboot, or attempts to at least. Setting it to “Never” did the trick after > a reboot. To repro the failure, turn it to 10 minutes and wait, decoding > will start seeing audio delays. No reboot required to force the failure. > > > > Each sample from the audio buffer (50/per 15 seconds for FT8) should take > roughly 280uS. I start seeing several samples in each group of 50 take > between 400-700uS. As a result not all 50 required audio samples are > collected in the time allowed and the period is skipped and the .WAV file > (if turned on) is not written out. If you turn on Save ALL and you see > missing .WAV files in the directory, this is another symptom. > > > > LatencyMon will show all is good. Changing C states and Turbo Boost and > any available such tweaks had no effect. Slide a random window around with > the mouse fast for 10- 15 seconds to raise CPU above 10% for a decode > period, or simply run any program that eats enough CPU cycles to get above > 10%, all is good. I had resorted to running a Speedtest modern app and > just letting it sit open on the desktop, tucked out of the way. Minimizing > it dropped the CPU% too much. Its animated GO button was just enough to > get me to 12%. > > > > I tried to repro this on a similar model HP laptop but with a Core i3 and > 1080p display, otherwise same packaging, 4GB RAM and 128GB SSD, same Intel > UHD620 GPU but it worked fine below 10%. Looked at its setting and it was > 10 minutes, so this issue seems to be very particular. > > > > Here is the Advanced Power Options screen snapshot: > > > > I would like to thank Mike W9MDB for his many hours of assistance during > this exercise, we now have the means/knowledge to easily spot such > effects. Understanding the reason for them is still an art and likely case > by case. > > > > - Mike K7MDL > > > > > > > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel >
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