iTop Screen Recorder Pro is not as intuitive as many screen recording apps I've seen, but it's certainly ambitious, packing a video recorder, audio only recorder, a screenshot app, and a video editor including a handful of transitions. For video recording there are different modes, including a gaming mode that does use the GPU -- when you select that mode it performs a quick test to see if your hardware qualifies, & if not, prevents you from selecting that mode. Recording performance is going to depend on your hardware, and the source you're recording. Bear in mind that if you're going to record 1080p or 4k video playing on your monitor, some of your hardware resources are going to be used playing that video. That probably goes double if you're going to record game play. You still need enough hardware resources left over to compress the video, and you need to be able to write that compressed video to disk at the same rate that it's created. Some video encoding formats may work better with your GPU than others, or you can forget the GPU & use only the CPU, where again your choice of encoder may matter. OBS & an app like Ashampoo's Snap let you choose which encoder to use, while iTop Screen Recorder Pro doesn't give you those same kinds of choices. It's easier that way, but you may not get what you're after. That said, if your hardware isn't up to the task you're not going to be successful no matter the software & encoder you use.
Installing & registering iTop Screen Recorder Pro adds the program folders, one each for the screen recorder & screenshot tools, 3 folders in ProgramData [one is an iObit folder], 3 folders in Users\ [UserName]\ AppData\ Roaming\, 1 folder in Users\ [UserName]\ AppData\ LocalLow\, & 1 folder in Users\ [UserName]\ Pictures\. Portions of the registry are rewritten -- I recorded 52428 new entries -- while the app itself uses a couple of keys, plus an uninstall key, but also takes over several file type associations [so if you double click an associated file the screen recorder opens].