Thank you for contacting Intel.
Yes. You can install any mix of supported SFP optical modules, SFP modules or direct attach cables on the same dual port adapter. You can plug any supported module into any port. Refer to website below for more information:
SFP+ Modules, SFP Modules, and Cables Compatible with X520 Series
Feel free to contact us again if you have further questions.
Sincerely,
Sandy