I am attempting to utilize a microsd card as the proxy cache store on a RB433UAH, but the results are awful.
The cache software works as expected. The correct files are cached and returned to the user as per my tests of the spec. However, performance is terrible. When caching to RAM, I can consistently push the WLAN throughput to 20-25Mbps delivering cached content. The CPU on the board sits around 5-25% used and everything is smooth. When I move the cache to the microSD disk store, throughput drops to around 8-10Mbps and CPU utilization jumps to 100%. This is repeatable throughout all of my tests.
It seems that read/writes from the SD card are too intensive on the CPU for this to be a viable store for http proxy content caching. Any help in resolving this performance issue would be greatly appreciated.
For what its worth, I’m running RouterOS 4.16. The board is a RB433UAH. It has a R2N radio. The microSD cards I’ve tested are Kingston SDHC Class 4 8GB and Sandisk SDHC Class 4 8GB.
At this point I’m considering dumping the Mikrotik board in favor of another brand. The 80-90 Mb of free RAM is not enough to effectively cache the object that I need to deliver.