Shadow wrote:


Last night I synched my time, turned off my network, closed
windows. When I started up today I opened Wireshark, turned the
network back on and time was spot-on (nothing showed on Wireshark
other than the usual ARP stuff and the Neutron query).
After it was on for 3 hours I checked the time and it was 4
seconds off. I disconnected the network again, etc et al, and when I
had rebooted the time was exact, no delay. I did NOT correct the time
before rebooting.
IOW the BIOS time seems to be working fine.
I always assumed Windows used the BIOS hardware clock and not
some "internal software clock".
I read somewhere that BCLK is used for overclocking. My BIOS
settings are set to default. What could be altering the BCLK time by
so much ? And could adding memory have affected it somehow ?
TIA
[]'s

Well, it's either the absolute frequency of BCLK which
is off, or, something is preventing clock tick interrupts
from being serviced.

The best references I've seen on the various clocks in a
computer, is on the VM hosting software company web sites.
They usually explain what clocks are inside a real PC,
and how the virtualized environment provides those same
clocks as "fakes". But it also teaches you about how
clocks work on the host itself.

If you have a modern multi-core Intel processor, you
can try locking the cores together temporarily as a test.
The machine can save power if the cores operate
independently on frequency, but it also causes some
complications when handing clock information from
one core to another. My other machine, the core clocks
are locked, and turbo is disabled (to prevent overheat).

Paul