HEN AMD ANNOUNCED the RX 6500 XT and RX 6400, it said the latter would be exclusive to pre-built OEM PCs. Several months later, AMD changed its mind and the Radeon RX 6400 is now available as an add-in board from several graphics card vendors. The PowerColor RX 6400 ITX perhaps isn’t the ideal model, since the biggest selling points for the RX 6400 are that it doesn’t require any extra power connectors and it can fit in a single-slot, half-height form factor. If you happen to have a slim PC, about the only other options besides the RX 6400 are extremely weak solutions such as the old GT 1030 or RX 550 from five years ago.
The Navi 24 at least brings some features up to the modern era. You get PCIe 4.0 support, ray-tracing hardware, and 4GB of GDDR6 backed by a 16MB Infinity Cache. However, the PCIe link is only four lanes, and in testing with a PCIe 3.0 connection, performance dropped by nine percent on average. The ray-tracing support also barely counts, and while we tested performance at 1080p medium, the best result from a demanding DXR (DirectX Raytracing) game was only 15fps, with several DXR games landing in single-digit frame rates. Finally, Navi 24 was originally intended for laptops where it would be paired with processors that have integrated graphics and hardware for video encoding and decoding. To save die space, Navi 24 lacks any form of H.264 or H.265 encoding support—though it can decode those formats just fine.