What game, resolution, monitor, monitor connection type (DVI/HDMI/VGA), desired FPS you wanna be at?
For example, your CPU in CS: GO at 1920x1080 resolution, most or all settings maxed goes up to 250 fps, BUT that with dual-channel 3200 Mhz RAM and RTX 2XXX family and the like. On 1050 more like up to 150 fps, but again with dual-channel 3200 Mhz RAM. So unless you want that high you'd need another 8 GB identical stick to run dual channel as that would help, and depending on the exact fps you want you may need better RAM/GPU, etc, so first decide on your expectations. And problems of stutters or input lag or fps drops are also related to the monitor, the resolution you play at, the Hz (Display Rate) of your monitor, the connection of it and that's on the hardware side, rest could be bios/driver/OS or software issues, but since you said you tweaked your pc to the max, maybe this is not the case? I don't know. Another factor since you mentioned input delay would be the input of course, so your mouse if it has 500 Hz 1000 Hz 2000 Hz modes the lower the Hz means faster reaction time so lower input delay/lag but in some cases, conflicts happen and a higher setting could lead to better performance. That's all I can say without the aforementioned specifics.