docs: RDNA4 fast and accuracy sets, FP8 and 16-bit, before and after
This commit is contained in:
1 parent
11c84193e6
commit
cf741c2e3d
2 files changed
+11
-2
No files matched your search
@@ -67,7 +67,7 @@ The gfx12 M variant can use native e4m3 FP8 WMMA with `D4R_NATIVE_FP8=1`. Its ac
|
||||
|
||||
In that build the GEMM activations live in LDS as e4m3 bytes (`SWIN_A8` in `swin_common.h`). Every value is encoded once where it is produced, four at a time with `v_cvt_pk_fp8_f32`, and an operand load is one 8-byte LDS read; the earlier build kept f16 values and encoded them again at every operand load (up to 16 times per value in the MLP). The instruction rounds like NVIDIA's conversion but encodes overflow as `0x7f`, so values are clamped to ±448 first with the NaN-propagating packed minimum and maximum (`codes4`). It equals `half_to_e4m3` for every non-NaN f16 input on an RX 9070 XT; a NaN encodes as the NaN code `0xff`, where the reference keeps its sign (`0x7f` or `0xff`). The accuracy build of these layers rounds each k32 step with `v_fma_mix` (`K32_MIX`; `-DK32_NO_MIX` restores the convert-and-round form) and its stored codes still equal `swin_model.py`. The patch merge reads the stored output codes from a byte image. `-DSWIN_NO_A8` restores the previous operand path. Builds without `D4R_FP8_WMMA` (RDNA3, and RDNA4 with `NativeFp8` off) compile to the same code as before.
|
||||
|
||||
RX 9070 XT (gfx1201), 1280×720 → 3840×2160, D3D12 harness, DLSS 310.7: the five Swin layers went from 3.99 ms to 1.37 ms per frame in replay (enc1 0.97 → 0.28, enc2 0.42 → 0.17, enc3 6 × 0.22 → 6 × 0.08, dec2 0.41 → 0.15, dec1 0.89 → 0.31), and the whole evaluation from 5.9 ms to 2.8 ms of GPU time (2.4 ms when the GPU is not left idle between frames) ([performance.md](performance.md#rdna4)). The layer outputs are byte-identical to the previous build on recorded launches, and the harness output is byte-identical over a 12-frame temporal sequence. The accuracy build's stored codes equal `swin_model.py` on sampled blocks of all five layers. The complete accuracy set costs 3.05 ms per evaluation in the same harness (2.59 ms under load) against 2.77 ms (2.37 ms) for the fast set; before the encoder, rounding and wave64 changes it cost 3.54 ms (3.01 ms). On gfx12 the accuracy builds of M's post and downsample kernels are wave64 with denormal handling kept; the image was identical to the wave32 accuracy set over an 8-frame temporal sequence.
|
||||
RX 9070 XT (gfx1201), 1280×720 → 3840×2160, D3D12 harness, DLSS 310.7: the five Swin layers went from 3.99 ms to 1.37 ms per frame in replay (enc1 0.97 → 0.28, enc2 0.42 → 0.17, enc3 6 × 0.22 → 6 × 0.08, dec2 0.41 → 0.15, dec1 0.89 → 0.31), and the whole evaluation from 5.9 ms to 2.8 ms of GPU time (2.4 ms when the GPU is not left idle between frames) ([performance.md](performance.md#rdna4)). The layer outputs are byte-identical to the previous build on recorded launches, and the harness output is byte-identical over a 12-frame temporal sequence. The accuracy build's stored codes equal `swin_model.py` on sampled blocks of all five layers. The complete accuracy set costs 3.06 ms per evaluation in the same harness (2.59 ms under load) against 2.77 ms (2.38 ms) for the fast set; with the previous FP8 layers it cost 6.49 ms (6.32 ms). On gfx12 the accuracy builds of M's post and downsample kernels are wave64 with denormal handling kept; the image was identical to the wave32 accuracy set over an 8-frame temporal sequence.
|
||||
|
||||
The gfx11 refactor and gfx12-layout shim matched the recorded gfx11 replays and 88-frame K/M harness images byte for byte on the RX 7700 XT. rocjitsu gfx1201 replay comparisons put the native K layers within 96–109 dB PSNR of gfx11, and M differed in 0.001–0.3% of e4m3 bytes. These are emulator results, not RDNA4 hardware results. rocjitsu's FP8 arithmetic is not hardware-checked; bit-exactness, speed and driver stability on an RDNA4 GPU remain unverified.
|
||||
|
||||
|
||||
Reference in new issue
Block a user