using the MPS430F5658 we are using the sample MSP430USBDevelopersPackage_5_20_06_02 code to emulate a SD drive. The transfers are very slow with a typical rate of 330 KB/sec. During a test early on in the project it was up to 1.4 MB/sec which would be acceptable. Nothing in the USB code has been changed. The test is performed with the call to read the SD card in the module MSC.C disabled for all blocks past the directory but this is only a speed test so that is acceptable. The internal buffer has been tried at its original size (512 bytes) and for sizes up to 4096 bytes with no effect. Note that enlarging the buffer size did improve speed when this was first tried.
The only thing that we can see which has changed is windows with all its updates.
Is there any known windows issue that could be a problem with the sample code and current updates for windows?
Baring that, and not being knowledgeable about USB protocols. is there something which can be looked at to diagnose this?
