whats the highest temp this burner can go?

For comparison to electric this 8" electric large stovetop element http://amzn.to/2rGUUug says 2600 watts in the listing.

2600 x 3.4 btu's per watt = 8840 btu's.

I can't find any solid info specific to that stove. Butane can burn hot enough to melt some metals, in the right circumstances. That stove probably produces 8,000 BTUs. A small gas burner on a stove in a home kitchen probably produces around 7,000.

If you're wondering if it's really hot enough to cook on, yes, it is. I've had one fro 20 years for camping and using at home when the power goes out. Those stoves get hot enough for any normal cooking.