Is my gtx 1080 ti render times ok?

I used the bmw render scene that was posted on this forum and the latest 2.78c blender build and with 480x270 tile size and 20 samples i get

Time: 38.78 secs

Can someone perhaps direct me where to go to compare these scores or maybe help me find a baseline render settings that a bunch of people are using to compare scores? Im not sure if this score is very good tbh. Kinda seems slow if you ask me.

The answers you seek are in the BMW thread in which you found the BMW file.

Hi.

https://blenderartists.org/forum/showthread.php?417834-GTX-1080-Ti-Various-Benchmarks-(BMW-Classroom-fishy-cat)

You keep in mind that BMW scene used there is the scene downloaded from link in first post in that thread, and not BMW scene that you can find in this forum (They have different samples configurations)

Scenes:
https://code.blender.org/2016/02/new-cycles-benchmark/

I think the render time you get with BMW scene from this forum, is good.