opencl: default the FA c8 cluster width to 16 on X1E (performance tuning) - #26433
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An X1-85 sweep (driver 863, 6 CU; GGML_OPENCL_FA_CL_C in {0,8,16,32}) measured
the wider cluster as a real DK128-GQA4 decode win on X1E: +30%/+28% at kv
4096/8192 (95.89->124.66, 97.18->124.49 GFLOPS), peaking at C=16 (C=32 falls
back to 106-110 GFLOPS, so this is not thermal drift), with DK64, GQA1, GQA8
and quantized-KV configurations all neutral.
X1E was left at the kernel-default width when X2E got 16 because its compiler
holds the default width unspilled and wide-C was unmeasured there; the sweep
shows the wider cluster wins anyway (fewer position streams per subgroup is
the deciding property at DK=128, not just register pressure).
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Signed-off-by: Gabe Goodhart <ghart@us.ibm.com> * origin/master: (383 commits) cmake : introduce semantic versioning (ggml-org#26839) gguf : harden loader against malformed tensor dims and metadata types (ggml-org#25596) kleidiai: Add runtime feature detection mechanism for aarch64/kleidiai (ggml-org#26076) model : disallow integer dflash sliding_window_pattern (ggml-org#26900) sync : ggml cmake : add config version support (ggml/1582) server : support slot save/restore with media inputs (ggml-org#26640) ui: add read_media tool (ggml-org#25877) opencl: default FA c8 cluster width to 16 on X1E (ggml-org#26433) tests : update speculative params (ggml-org#26925) vulkan: add TQ2_0 (ternary) support (ggml-org#25850) wavtokenizer-dec : bound posnet/convnext block_count against n_layer_all (ggml-org#26892) convert : handle per_layer_config in Gemma4 (transformers 5.15) (ggml-org#26882) opencl: use flat mv q5_k when weight exceeds image1d_buffer_t limit (ggml-org#26880) chat : fix muse-glimmer detection of tool calls after EOM (ggml-org#26879) ci : add missing release check (ggml-org#26923) CUDA: only disable CUDA graphs when mul_mat_id actually needs a stream sync (ggml-org#26802) cuda : add warp-per-row wkv7 kernel for single-token decode (ggml-org#26111) spec : update speculative-simple (ggml-org#26904) chat : tighten bare function parsing for Qwen models (ggml-org#26793) ...
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This PR is to set a wider cluster for Adreno X1-85 based on a performance sweep run.
Overview
Additional information
Perf gain: +30%/+28% at kv 4096/8192 (95.89->124.66, 97.18->124.49 GFLOPS), peaking at C=16.
Requirements
For Adreno X1-85 only