We have tested and used the latest version of Intel(R) Rapid Storage Technology and we have not seen any similar issues. I suggest you using the “volume write back cache” option as enabled when using RAID configurations. Also, for troubleshooting purposes you can also try using Intel(R) Rapid Storage Technology 9.6 available on this site:
Further than this, we regret to inform you that we do not evaluate the performance of the specific RAID configurations used. In this case, if you have concerns about the performance and data transfers on your computer, please refer directly to your computer manufacturer.
Please be aware that the RAID controller on your system is a software RAID solution, which means that the data stripping is calculated by the processor and using the system resources, in addition the performance may be affected by the rest of the software running on the background, the performance test application being used, the type of memory and processor installed and also the settings of the performance tester which may have a big impact on the results.