This Gigabyte graphics card is one option for you if you're upgrading your computer. It has a 16 GB GDDR6 memory. The GPU clock speed of this card is 1.70 GHz.
From eBay
Gigabyte gv-r68gaming oc-16gd amd radeon rx6800 graphic board gddr6 16gb gaming
Overclockers
Gigabyte Radeon RX 6800 Gaming OC 16GB GDDR6 PCI-Express Graphics Card