How to troubleshoot slow read/write times from a multifunction printer/scanner's SD card?

I have been trying to help a friend diagnose a problem with their technology. On their WiFi network, they have an Epson WiFi printer/scanner and several Windows 7 SP1 systems. The printer/scanner has an SD card slot to store the scans. Their WiFi network works well. The speeds are within the appropriate range. However, accessing the files on the printer/scanner's SD card slot is amazingly slow . What steps can I take to diagnose this problem, and hopefully fix it? What I've tried so far: I took the SD card out of the printer, and inserted it directly into a computer. Reads and writes to the ca

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