The estimator is for streaming, if you "just" want to record to your harddisk I would use different settings:
How to make high quality local recordings
As described in the guide, if you put your bitrate to 1000 and buffer to 0 (using x264) you unlimit the bitrate, now in the advanced settings of OBS activate the custom x264 encoder settings and add crf=18. Also in the advanced settings, change your x264 CPU preset to superfast (if you notice too much cpu usage, you can also lower it to ultrafast).
With that set you might be able to record 1080p 30fps smoothly without really noticing it, 60 you have to test. It depends a bit on what you do at the same time.
If your mainboard supports it, you could probably also offload the cpu load and use the quicksync encoder of your CPU. For recording that would be even better. You wouldnt notice that OBS is even running with that.
If I misunderstood and you want to stream, for the estimator your Graphics card would be similar to the Intel HD 3000, maybe a bit better but the settings would be similar, so you can select that.