Leaked FSR 4 examined on RDNA2 in INT8 mode supported by Xbox Sequence consoles

Few days in the past, an AMD engineer leaked the supply code of FSR 4 designed for RDNA2 {hardware} supporting INT8 operations, equivalent to Xbox consoles. At present, video games on consoles use FSR3 executed in FP16 mode, however INT8 operations are twice as quick. So in the identical time, you’ll be able to course of code that's 2x extra complicated, which in upscaling results in higher picture high quality. On single 32-bit compute models you’ll be able to course of:

single FLOAT 32-bit operations (FP32) double FLOAT 16-bit operations (FP16) 4 Integer 8-bit operations (INT8) eight Integer 4-bit operations (INT4)

Digital Foundry examined this INT8 answer and evaluate it to FP8 model launched for RDNA4. For individuals who should not software program engineers a dictionary:

INT8: an 8-bit integer operation on numbers like 1, 2, 4 and so forth. In the event you divide 5/3 on this mode you’ll have outcome 2. This isn't good, but it surely's adequate as a result of we're working with a flat 2D pixel buffer, not a 3D area the place float precision is critical FP8: an 8-bit floating operations on quantity like 1.0 2.0 4.0 and so forth. In the event you divide 5/3 on this mode you’ll have outcome 1.6666667. Velocity might be precisely the identical like in INT8 however {hardware} compatibility is proscribed to RDNA 4 FP16: an 16-bit floating operations on quantity like 1.0 2.0 4.0 and so forth. In the event you divide 5/3 on this mode you’ll have outcome 1.66666666666667. However code is 2x slower than INT8 or FP8

{Hardware} compatibility seems to be like this:

RDNA 1 on PC – FP32, FP16 RDNA 2, 3 on PC – FP32, FP16, INT8, INT4 RDNA 4 on PC – FP32, FP16, FP8, INT8, INT4, PS5 – FP32, FP16 Xbox consoles – FP32, FP16, INT8, INT4 Steam deck – FP32, FP16, INT8, INT4 PS5 Professional – FP32, FP16, INT8, INT4

As you’ll be able to see each Xbox Sequence consoles help INT8. This mode can be supported on PS5 Professional however it isn’t supported by PS5 which is proscribed to older FP16