sparse_attn: drop stale FMHA-vs-sparge perf section from README

example/ck_tile/50_sparse_attn/README.md

@@ -29,19 +29,7 @@ Not yet ported (upstream pinned to commit [`ae5b629`](https://github.com/thu-ml/
 
 *MI300X, b=2 h=16 s=8192 d=128 fp16, 5 seeds × 9 sparsity points. All three modes dispatch to the `kM0=64 padK=0` tile bucket at this shape.*
 
-On the canonical recipe shape, `none > warp > block` at every measured sparsity, with no crossover. The per-block guard adds +33..+35 VGPR (6..9 spills) on this tile configuration, depressing occupancy. `warp` is +0..+4 VGPR. The default is `-pv_mode=warp` (preserves R25 A1 behaviour); switch to `none` for the no-skip baseline or `block` to exercise the upstream-aligned variant. A shape sweep is needed before recommending `block` as default — the `kM0=128` path has Δ ≈ 0 VGPR for per-block and is a candidate.
-
-## Performance
-
-At b=2 h=32 s=16384 fp16, sparge (vsa backend) reaches **1.78× FMHA throughput at topk=0.4** and **5.04× at topk=0.1**, and stays above 1.0× across the full topk range.
-
-![Speedup vs sparsity](docs/speedup_vs_sparsity.png)
-
-*Speedup vs FMHA, b=2 h=32 s=16384 d=128 fp16. Shape chosen to match Fig. 10 of the SpargeAttn paper ([arXiv:2502.18137](https://arxiv.org/abs/2502.18137); Mochi-1, 22K context, head_dim=128); s=16384 is the closest grid point. Gray-outlined points have >30% inter-rep spread.*
-
-![Kernel breakdown](docs/kernel_breakdown.png)
-
-*BlockMap (`_pre`) stacked on attention (`_attn`), b=2 h=32 d=128 fp16 topk=0.4. BlockMap is roughly 17% of total at s=16384.*
+On the canonical recipe shape, `none > warp > block` at every measured sparsity, with no crossover. The per-block guard adds +33..+35 VGPR (6..9 spills) on this tile configuration, depressing occupancy. `warp` is +0..+4 VGPR. The default is `-pv_mode=warp`; switch to `none` for the no-skip baseline or `block` to exercise the upstream-aligned variant. A shape sweep is needed before recommending `block` as default — the `kM0=128` path has Δ ≈ 0 VGPR for per-block and is a candidate.
 
 ## Usage