[SCYL] add chapter for performance reference in SYCL.md (ggml-org#23315)

* add chapter for performance reference

* rm unsupported GPU

Author: arthw

README.md

@@ -280,7 +280,7 @@ Instructions for adding support for new models: [HOWTO-add-model.md](docs/develo
 | [Metal](docs/build.md#metal-build) | Apple Silicon |
 | [BLAS](docs/build.md#blas-build) | All |
 | [BLIS](docs/backend/BLIS.md) | All |
-| [SYCL](docs/backend/SYCL.md) | Intel and Nvidia GPU |
+| [SYCL](docs/backend/SYCL.md) | Intel GPU |
 | [OpenVINO [In Progress]](docs/backend/OPENVINO.md) | Intel CPUs, GPUs, and NPUs |
 | [MUSA](docs/build.md#musa) | Moore Threads GPU |
 | [CUDA](docs/build.md#cuda) | Nvidia GPU |

docs/backend/SYCL.md

@@ -5,6 +5,7 @@
 - [News](#news)
 - [OS](#os)
 - [Hardware](#hardware)
+- [Performance Reference](#performance-reference)
 - [Docker](#docker)
 - [Linux](#linux)
 - [Windows](#windows)
@@ -51,9 +52,8 @@ The packages for FP32 and FP16 would have different accuracy and performance on
 
 ## News
 
-- 2026.04
-
-  - Optimize mul_mat by reorder feature for data type: Q4_K, Q5_K, Q_K, Q8_0.
+- 2026.04-05
+  - Optimize mul_mat by reorder feature for data type: Q4_K, Q5_K, Q6_K, Q8_0.
   - Fused MoE.
   - Upgrate CI and built package for oneAPI 2025.3.3, support Ubuntu 24.04 built package.
 
@@ -150,6 +150,13 @@ On older Intel GPUs, you may try [OpenCL](/docs/backend/OPENCL.md) although the
 
 NA
 
+## Performance Reference
+
+
+To get the supported LLMs, GPUs, and performance reference, please check [Performance of llama.cpp on Intel GPU with SYCL backend](https://github.com/ggml-org/llama.cpp/discussions/23313).
+
+You could update your test result in it directly.
+
 ## Docker
 
 The docker build option is currently limited to *Intel GPU* targets.