Looks like are both have same type, rank, speed and size. Mixing of memory is supported. You can refer below link for more details on memory installation guidelines.  [URL] 
Hello,Our R930 has Samsung M393A2K43BB1-CRC dual rank memory modules. We would like to buy more RAM, but I only found Samsung M393A2G40EB1-CRC dual rank RAM. Little difference in their name.  Is there be any problem If I mix these RAMs together? Thanks,F
RAM difference R930