Very Low desk performace on SDXC

Hi

Once I place Disk file on a SDXC card (64G NTFS), the performace is extermaly low. Normaly my card can has speed 40mb/s read and 80mb/write under windows 8, in VM, it almost unable to read. If I replace the card with an Class 4 SDHC card, it works as expect.

Is there any known issue with SDXC and VMPlayer 5?

Regards,

Yi