Scimark Multigraphics Lite: Performance Tips and Tricks
1. Keep software up to date
- Update: Install the latest Scimark Multigraphics Lite build and GPU drivers to get bug fixes and performance improvements.
- Changelogs: Check release notes for performance-related fixes before benchmarking.
2. Use appropriate test sizes
- Right problem size: Choose benchmark/problem sizes that fit your GPU memory to avoid paging or reduced occupancy.
- Scale tests: Run small, medium, and large sizes to see where throughput and latency trade off.
3. Optimize input/output formats
- Use native formats: Prefer the file and texture formats recommended by the tool to avoid costly conversions.
- Batch I/O: Group reads/writes to minimize I/O overhead during runs.
4. Tune parallel settings
- Threads/blocks: Match kernel launch parameters (threads per block, blocks per grid) to your GPU’s architecture—use multiples of warp/wavefront size.
- Stream concurrency: Use multiple CUDA/OpenCL streams if the tool exposes them to overlap compute and data transfer.
5. Minimize data transfers
- Pinned memory: Use pinned (page-locked) host memory when transferring large buffers to reduce transfer latency.
- Keep data on device: Reuse device-resident data across runs rather than copying repeatedly.
6. Profile and identify hotspots
- Profilers: Use NVIDIA Nsight / AMD Radeon GPU Profiler / Intel VTune as appropriate to find bottlenecks.
- Focus: Prioritize optimizing kernels that consume the most time or memory bandwidth.
7. Improve memory access patterns
- Coalesced access: Arrange data so threads access contiguous memory to maximize throughput.
- Shared/local memory: Use shared (CUDA) or local (OpenCL) memory for frequently reused data to reduce global memory pressure.
8. Reduce branching and divergent paths
- Branch avoidance: Refactor kernels to minimize divergent branches within warps/wavefronts.
- Predication: Where appropriate, use predicated operations instead of branching.
9. Leverage hardware features
- Tensor/RT cores: If available and supported by the benchmark kernels, enable specialized units for matrix ops.
- FP16/BF16: Consider lower-precision compute modes where acceptable to increase throughput and decrease memory use.
10. Repeatable, controlled runs
- Environment: Disable background apps, set consistent power/performance modes, and ensure thermal stability.
- Multiple runs: Average several runs and report variance to avoid misleading single-run results.
11. Compare fairly
- Baseline: Keep a documented baseline configuration (driver, OS, power settings).
- Normalized metrics: Report per-watt and per-core or per-GFLOP metrics when comparing systems.
12. Common quick fixes
- Power state: Set GPU to performance mode to prevent throttling.
- Cooling: Improve cooling to avoid thermal throttling during extended runs.
- Dependencies: Use optimized math libraries (cuBLAS, MKL, etc.) if the benchmark can link to them.
If you want, I can generate a short checklist tailored to a specific GPU/OS or create command-line examples for profiling and launching tuned runs.
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