So I recently got a good paying job and decided to upgrade my rig from a i7-7700 and a gtx 1070 TI to an i7-9700K, keeping my old GPU. I only upgraded my cpu, since everytime I loaded task manager, it confirmed that my cpu was at a 100% almost all the time under load and my gpu at only around 40%. I also decided to upgrade my monitor from a 1920x1080p 144Hz to a 2560x1440p 144Hz. With my gtx 1070 Ti overclock (+150 core clock and +500 memory clock) combined with my i7-9700k overclock (4.6 GHz) I though that I would not have to upgrade my GPU yet. However, running task manager and MSI Afterburner shows that my poor gtx is having a hard time running new games at 2560x1440p. The games were running at low fps with sometimes extremely noticeable and annoying stutter. What gpu, if needed, should I upgrade to?