@Trailjacker

It's a little bit of both. These are my overclock settings. ymmv

arm_freq=1300
gpu_freq=500
sdram_freq=500
over_voltage=6
v3d_freq=525

@obsidianreq You didn't specify the emulator or version of retropie. There are two n64 emulators, and multiple video plugins for mupen64plus). Which one ? (check runcommand menu).

You didn't mention the hardware. You just said "x86 system". Which is quite generic. 32 or 64 bit ? which os ?

@lilbud I used fonts that were close to the original. Then outlined the text in red, outlined the black polygon and created the logo myself. Used the "clouds" filter to make the background, and found a nice flame image online and masked the text out for that.

N64 is 640x480 usually, so it just kinda looks bad when you scale the original graphics up. So I pick titles that I can re-create in HD without having to dig out a paint brush.