"Benchmark and hardware test" command
Using "Benchmark and hardware test" command you may compare performance of RAR compression algorithm on different computers and detect possible compression errors caused by hardware failures.
This command generates random data, which contain specially introduced redundancy increasing load to processor and memory. Then data are passed through RAR compression and decompression algorithms and output of decompression algorithm is compared with source data. If any difference found, WinRAR reports "Errors found - Yes" in the command window. Also WinRAR displays a size of processed data and compression speed, current and resulting, in kilobytes per second. You may use the resulting speed value to compare RAR performance in different conditions. For example, "Benchmark" command may be helpful, when you need to choose a new computer and wish to know which one will compress data faster. Only the general compression algorithm in "Best" mode with 4096K dictionary is called, all additional filters and algorithms are disabled, so it measures performance of core RAR compression on worst case like data.
Using "Multithreading" option you can compare performance of usual single threaded and multithreaded (optimized for multiprocessor architectures) versions of RAR compression algorithm. Depending on results, you can enable or disable multithreading in General settings dialog dialog.
It takes some time to fill the compression dictionary, which is empty in the beginning. Until it is done, the speed value is inconsistent, so the command window starts to display the current speed only a few seconds after activating. Resulting speed is displayed when at least 10MB of source data are processed, collected statistics is enough to get an accurate result and current speed changes are near zero. After the resulting speed has been set, it is not changed more. Though source data are random, their redundancy level and other parameters are always the same. So this command will report practically the same current speed regardless of execution time, provided that system load is not changing.
It is not guaranteed that different WinRAR versions will report same compression speed values, so if you use this command to compare performance of different computers, ensure that you run the same WinRAR version in all tests. Also it is recommended to close other applications before starting a benchmark.
"Benchmark" command is never finished automatically, you need to cancel it manually.
Considering the hardware test component, it cannot replace utilities specially designed for this purpose. It is not able to find a reason of failure, it can only detect that decompressed data do not match originally compressed data, what may happen because of different reasons like unreliable memory, overclocked processor or other hardware problems. If you are going to use this command to test hardware, it is recommended to run several copies of WinRAR simultaneously executing this command. Every such copy takes about 35 MB, so if you know the amount of free memory and run enough copies to allocate it, you may check all available physical memory. For hardware test purpose it is a good idea to run WinRAR for a long time, several hours or even more.