NZXT H510i
ATX, mATX, Mini ITX
NZXT H510i
ATX, mATX, Mini ITX
A graphics card with max. 381mm can be installed in the NZXT 510i. This dimension applies to both installation variants. However, you still have to consider whether you want to install additional fans or a radiator in the front. This would of course reduce the maximum length.
I haven't found your GraKa yet, so I can't say whether it would fit.
I have a Sapphire Nitro+ Radeon RX 5700 XT in the same