The WD Red Plus 6TB CMR with 256MB is available now under the part number WD60EFPX. The part number so far available to channel was WD60EFZX.
WD60EFPX vs WD60EFZX : Higher Cache, Lower RPM, almost similar xfr rates
The biggest difference is the cache. WD60EFPX has Double the cache (256MB) compared to 128MB of WD60EFZX. However the WD60EFPX is 5400RPM compared to 5640RPM of WD60EFZX.
This lower RPM on WD60EFPX means a lower transfer rate, though marginally. WD60EFPX is a little slower at 180MB/s , when compared with WD60EFZX at 185MB/s. The number of platters in both the drives seems to be same since there is no difference in weight.
Mixing the drives shouldn't be a problem since both of them are CMR and would have similar firmware.
|Internal Transfer Rates||180MB/s||185 MB/s|