Question Getting a lot of choppy output despite having high fps

[Omeggga]

So I just got my laptop back from repairs, I noticed they installed a new motherboard and the GPU went from 6 GB GDDR5 to 8 GB. Awesome, not only that but I noticed the new CPU is more undervoltable, so I rig it up to a -90 mV and it runs peachy, highest it ever goes is around 95C on Apex Legends and Halo Infinite MP. Not bad for a laptop.

But there's a problem.

On a lot of games it feels really really choppy. Despite having 75 FPS (that's what I cap it out to to avoid higher-than-necessary temps) I notice some really odd stuttering. It's particularly noticeable in Left 4 Dead 2 and in Halo The Master Chief collection. I check thermals... they're fine, 70C to 80C on CPU, expected of a laptop unfortunately. I check the hard drive, I move the installation of Halo MCC from my 5400 HDD to my m.2 SSD. Nada. Better but still choppy. I remove the undervolt and restart my PC, checking Throttlestop and... wow that did the tri- wait, no, no it didn't!

When I look at the numbers I see the fps being 75 but the 99 percentile going to about half of that sometimes, other times even lower. Since it's back from repairs I assume all drivers are completely up to date. I updated the nvidia driver myself to 511.23 before playing.

Specs are:
CPU: i7 7700HQ
GPU: Nvidia 1070 8 GB GDDR5
RAM: SODIMM 2400MHz, 16 GB
HDD: 2 NVMe drives (one for os (256GB), one for gaming (1TB)) and an HDD (2 TB, 5400 RPM)

I really don't know what to do here. Help me out please? ^^;

 

[Omeggga]

Update: I fixed it by disabling G SYNC. I also have V SYNC disabled. If you stumbled onto this post from google, try doing the same. I dunno what malarkey made it work but... I mean, stuttering is now rare enough that I can live with it. I call that a win.