PySerial slow when setting timeout

[BrendanSimon]

I have been setting the timeout attribute on my serial object when I know certain operations take longer (e.g. command to erase flash in my device). My API is always setting the timeout attribute, even for small/standard timeout periods.

It seems that setting the timeout attributes takes quite a while on my Win7 box -- approx 0.01 seconds (10ms) !!. Why does it take so long? Is it completely reconstructing the object? Even so, isn't 10ms a long time?

It is double trouble, as I reset the timeout to a default value after the receiving the expected data, which gain introduces another ~10ms delay.

Note: On my Win10 box, setting the timeout attribute takes approx 0.001 seconds (1ms)

Comms on my Win7 box takes x10 longer (i.e. x10 slower) that my Win10 box. It might be driver related perhaps? (STMicroelctronics VCP Driver - for an STM32F4 CDC device)

Does setting the timeout attribute have anything to do with USB Serial Drivers or not. I'm assuming not, but have no idea.

Am I misusing PySerial or is there a bug somewhere?

Thanks, Brendan.