DisplayPort 1.4a:
7680 x 4320 x 24bpp @ 120Hz (Requires two DisplayPort 1.4a links and DSC compression)
7680 x 4320 x 24bpp @ 60Hz (Requires either a single DisplayPort 1.4a link with DSC compression or two DP links with no compression)
7680 x 4320 x 36bpp @ 60Hz (Using DSC compression)
5120 x 3200 x 24bpp @ 60Hz (Uncompressed)
5120 x 2880 x 24bpp @ 60Hz (Uncompressed)
HDMI 2.1:
7680 x 4320 x 24bpp YUV420 or DSC @ 60Hz
7680 x 4320 x 30bpp YUV420 or DSC @ 60Hz
7680 x 4320 x 36bpp YUV420 or DSC @ 60Hz
3840 x 2160 x 24bpp uncompressed @ 120Hz
3840 x 2160 x 30bpp uncompressed @ 120Hz
3840 x 2160 x 36bpp uncompressed @ 120Hz
4096 x 2160 x 24bpp uncompressed @ 120Hz
4096 x 2160 x 30bpp uncompressed @ 120Hz
4096 x 2160 x 36bpp uncompressed @ 120Hz
RTX 3080 & RTX 3090 support 4 x 4K monitors the most at the same time.
RTX 3080 & RTX 3090 support 2 x 8K monitors the most at the same time.