Xilinx / Xilinx/Vitis_Accel_Examples
Curiosity of performance between host_memory_bandwidth and host_memory_bandwidth_xrt
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Description
Hi,
I have a question about the performance between host_memory_bandwidth and host_memory_bandwidth_xrt.
It seems that they have same kernel and similar host code, but the performance results are quite different.
For buffer size 32.00 KB example,
OpenCL host example is
Concurrent Read and Write Throughput = 12.1802 (GB/sec) for buffer size 32.00 KB
Read Throughput = 8.17289 (GB/sec) for buffer size 32.00 KB
Write Throughput = 8.26587 (GB/sec) for buffer size 32.00 KB
,while XRT host example is
Concurrent Read and Write Throughput = 12.4713 (GB/sec) for buffer size 32.00 KB
Read Throughput = 0.00397313 (GB/sec) for buffer size 32.00 KB
Write Throughput = 0.0040426 (GB/sec) for buffer size 32.00 KB
What is the main factor contributing to this difference?
Do XRT and OpenCL affect the performance significantly?
Contributor guide
First steps
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Research direction
Compare the host_memory_bandwidth and host_memory_bandwidth_xrt example directories, starting with the host-side timing and throughput calculations. Reproduce the 32.00 KB measurements shown in the issue and trace why the read and write results differ while concurrent throughput is similar. Done means identifying and documenting the main cause, including whether the XRT or OpenCL host paths account for it.
Written by the indexing model from the issue text.
Assessment
- Domain
- performance
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 20/100