heavy discontinuity/errors with TBS 6985

[piratko]

Hello,

Having some problems with HD channels - the higher the bitrate, the worse the symptoms. I have everything detailed here - https://tvheadend.org/boards/5/topics/13128

Any ideas? Is this a drivers issue? Tried two different PCs to rule out hardware incompatibilities, different motherboards and all - all the same

[kvaster]

It is hardware or software error which will be not fixed - TBS just ignores us. My solution was to through away TBS6985 and to buy four TBS6925 cards. They just work perfect.

Also problem is not only with HD channels on tbs6985. I advise you to try turning off three tuners and to use only one with tbs6985 and you will see that you're not having problems any more.

[Krobaruk]

For me I find putting the CPU under stress actually fixes the problem. I don't understand how this fixes the problem for me but try:
"stress -c 1"

TBS,

Any idea where the problem might be? Could it be the "Relaxed Ordering Bit" PCI setting? Disabling CPU frequency changes does not help.

[updatelee]

Sounds like it's a CPU power save issue. Try disabling Intel pstates and or cpufreq

UDL

[jonbanjo]

Has anyone managed to get to the bottom of this?

Having found "stress -c 1" clears the problem I have with HD channels, I thought I'd try something even simpler. Running the following python script will clear the problem for me:

Code: Select All Code

a = 0
while True:
  a = a + 1


So what happens? The CPU frequency goes up but setting the frequency scaling to "performance" to keep the processor at 3600Ghz makes no difference. There must be something else but what?

[jonbanjo]

Just one other comment. I have tried the open source drivers. Things are exactly the same with those.