want to know precise GC benchmarks

[a11e99z]

On Tuesday, 1 October 2019 at 16:12:18 UTC, a11e99z wrote:
> does anybody some kind of benchmark to test conservative and 
> precise GC?
> precise GC is better or not? is STW improving?

and another question about GC and app parameters:
> program.exe “–DRT-gcopt=gc:precise parallel:4” 
> “–DRT-scanDataSeg=precise” <input.data >output.data
are this 2 -DRT params combined or overwriting each other?
link to doc for DRT+GC 
https://dlang.org/spec/garbage.html#gc_config

I know about rt_options[] but asking about program args

why I want to know such info?
CodinGame sometimes use time-limit for bot move for example 
100ms, and bot will be disqualified in case no answer