From: David
Possibly not of immediate concern to time-nuts but an article had some
trigger words for them in the initial fixes to the much publicised
problems with Intel/AMD/ARM etc :
"After these changes, the time stamp returned by |performance.now| will
be less precise due to lower resolution. Some browsers are going a step
further and degrade the accuracy by adding a random jitter."
https://hackaday.com/2018/01/06/lowering-javascript-timer-resolution-thwarts-meltdown-and-spectre/
meltdown/spectre background
https://www.theregister.co.uk/2018/01/04/intel_amd_arm_cpu_vulnerability/
================================
David,
This API appears only to affect browsers.
On my Windows systems most have been patched, and I see no visible
difference on either PPS-synced, LAN-synched or Wi-Fi devices as recorded by
NTP. One PC showed an increase in CPU usage, but other PCs performing
similar tasks have not. That same PC showed a doubling of jitter from less
than 2 microseconds to less than 4 microseconds. It's an i5-4460 Haswell
processor.
http://www.satsignal.eu/mrtg/harstad-cpu-week.png
Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
Twitter: @gm8arv
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