# Review the performance results

## In this learning path

- [Introduction](https://learn.arm.com/learning-paths/servers-and-cloud-computing/bolt-merge/)
- [Overview](https://learn.arm.com/learning-paths/servers-and-cloud-computing/bolt-merge/how-to-1/)
- [Instrument MySQL with BOLT](https://learn.arm.com/learning-paths/servers-and-cloud-computing/bolt-merge/how-to-2/)
- [Run a new workload using BOLT and merge the results](https://learn.arm.com/learning-paths/servers-and-cloud-computing/bolt-merge/how-to-3/)
- [Instrument shared libraries with BOLT](https://learn.arm.com/learning-paths/servers-and-cloud-computing/bolt-merge/how-to-4/)
- [Review the performance results](https://learn.arm.com/learning-paths/servers-and-cloud-computing/bolt-merge/how-to-5/)
- [Next Steps](https://learn.arm.com/learning-paths/servers-and-cloud-computing/bolt-merge/_next-steps/)

## Overview
This section compares the performance of baseline binaries with BOLT-optimized versions. It highlights the impact of merged profile optimizations and shared library enhancements on overall system throughput and latency.

All tests used Sysbench with the flags `--time=0 --events=10000`. This configuration ensures that each test completes exactly 10,000 requests per thread, delivering consistent workload runtimes across runs.

## Baseline performance (without BOLT)

| Metric                     | Read-only | Write-only | Read + write |
|----------------------------|-----------|------------|--------------|
| Transactions/sec (TPS)     | 1006.33   | 2113.03    | 649.15       |
| Queries/sec (QPS)          | 16,101.24 | 12,678.18  | 12,983.09    |
| Latency avg (ms)           | 0.99      | 0.47       | 1.54         |
| Latency 95th % (ms)        | 1.04      | 0.83       | 1.79         |
| Total time (s)             | 9.93      | 4.73       | 15.40        |

## Performance comparison: merged and non-merged instrumentation

| Metric                     | Regular BOLT (read + write, system libssl) | Merged BOLT (read + write + libssl) |
|----------------------------|---------------------------------------------|--------------------------------------|
| Transactions/sec (TPS)     | 850.32                                     | 879.18                               |
| Queries/sec (QPS)          | 17,006.35                                  | 17,583.60                            |
| Latency avg (ms)           | 1.18                                       | 1.14                                 |
| Latency 95th % (ms)        | 1.52                                       | 1.39                                 |
| Total time (s)             | 11.76                                      | 11.37                                |

Second test run:

| Metric                     | Regular BOLT (read + write, system libssl) | Merged BOLT (read + write + libssl) |
|----------------------------|---------------------------------------------|--------------------------------------|
| Transactions/sec (TPS)     | 853.16                                     | 887.14                               |
| Queries/sec (QPS)          | 17,063.22                                  | 17,742.89                            |
| Latency avg (ms)           | 1.17                                       | 1.13                                 |
| Latency 95th % (ms)        | 1.39                                       | 1.37                                 |
| Total time (s)             | 239.9                                      | 239.9                                |

## Performance across BOLT optimizations

| Metric                     | BOLT read-only | BOLT write-only | Merged BOLT (read + write + libssl) | Merged BOLT (read + write + libcrypto) | Merged BOLT (read + write + libcrypto + libssl) |
|----------------------------|----------------|-----------------|--------------------------------------|------------------------------------------|--------------------------------------------------|
| Transactions/sec (TPS)     | 1348.47        | 3170.92         | 887.14                               | 896.58                                   | 902.98                                           |
| Queries/sec (QPS)          | 21575.45       | 19025.52        | 17742.89                             | 17931.57                                 | 18059.52                                        |
| Latency avg (ms)           | 0.74           | 0.32            | 1.13                                 | 1.11                                     | 1.11                                            |
| Latency 95th % (ms)        | 0.77           | 0.55            | 1.37                                 | 1.34                                     | 1.34                                            |
| Total time (s)             | 239.8          | 239.72          | 239.9                                | 239.9                                    | 239.9                                           |

**Note:** All Sysbench and .fdata file paths, as well as taskset usage, should match the conventions in previous steps: use Sysbench from PATH (no src/), use /usr/share/sysbench/ for Lua scripts, and use $HOME-based paths for all .fdata and library files. On an 8-core system, use taskset -c 7 for Sysbench and avoid contention with mysqld.

## Key metrics to analyze
- **TPS (transactions per second)** – higher is better
- **QPS (queries per second)** – higher is better
- **Latency (average and 95th percentile)** – lower is better

## Conclusion
- BOLT-optimized binaries clearly outperform baseline versions by improving instruction cache usage and shortening execution paths.
- Merging feature-specific profiles does not negatively affect performance. Instead, they allow better tuning for varied real-world workloads by capturing a broader set of runtime behaviors.
- External library optimizations (for example, `libssl` and `libcrypto`) provide smaller incremental gains, delivering a fully-optimized execution environment.