I use gatling, single gatling can press 2w qps
I am not certain exactly what you asked, but I guess it was how many QPS can k6 do in a given time, and you are saying Gatling can do 2 thousand QPS - I don’t know what 2w is … sorry.
In general given this comparison I would expect k6 to do more, how many … I don’t know. This all depends on your machine and what you are doing.
For example I have been able to do 3.3k RPS between two machines with 1gbps between them, where the problem in the end was … the 1gbps between the machines. Moving the nginx server to the same machine as k6, with 24cores(from 10 years ago, two X5660) I managed to get 33k RPS, although this is literally just doing stupid requests. It also turned out that the amount of VUs doesn’t matter in my case past like 50, because it is the network that is getting overwhelmed not k6.
All of this was without any kind of outputting the metrics to something, which I would expect will make things slower