For those of you not in the know, most current SD cards implement an Ultra High Speed bus (which is abbreviated UHS-I or UHS-1) because it is the 1st version of this bus. It has a maximum transfer rate of 104MB/sec. Since there are some cases which require higher transfer speeds, the SD card consortium has created a new bus called UHS-II (or UHS-2.) The difference is two-fold:
UHS-II raises the maximum transfer rate up to 312MB/s.
UHS-II uses an additional row of pins/contacts to get there.
This means that UHS-II cards can only be fully utilized if the device using it has physical support for these extra pins/contacts. If the device does not have these extra pins (and that’s pretty much all devices as of 2014), then the SD card will fall back to UHS-I mode.
SD Cards that support UHS-II
| SanDisk Extreme PRO (280MB/s) 16GB, 32GB, and64GB. | Oddly enough, SanDisk has another SD card called the Extreme Pro which only achieves 95MB/s, but *this* card (with a capital “PRO”) achieves a 280MB/s read speed and a write speed of 250MB/s. |
| Lexar Professional 1000x | Lexar says: Up to 150MB/s read transfer, write speeds lower. |
| Lexar Professional 2000x | Lexar says: Up to 300MB/s read transfer, write speeds lower. |
| Panasonic MicroP2 32GBand 64GB | Panasonic says: High speed transfer of 2.0 Gbps (~240MB/s.) Guaranteed data writing up to AVC-ULTRA Class200 mode. |
| Toshiba Exceria UHS-II | Toshiba says: 260MB/s read, 120MB/s write. |
SD Readers that support UHS-II
| Kingston MobileLite G4 | The Kingston MobileLite G4 was benchmarked against 2 other portable USB 3.0 SD card readers and came out with top marks. Definitely a great value at ~$10. |
| SanDisk Extreme PRO Reader | Not sure why this card reader costs $40. Perhaps since UHS-II cards cost so much right now, SanDisk thought it could charge a premium for the reader, too. |
Digital Cameras and DSLRs that support UHS-II
| Fujifilm X-T1 | A 16MP compact mirrorless digital camera which uses an APS-C sensor which is getting rave reviews right now for both its size and quality. UHS-II cards allow the X-T1 camera to perform up to 25% faster (according to this video.) |
| Panasonic Lumix GH4 | A 16MP mirrorless digital camera which is fast becoming popular for being a highly portable 4K video camera as well. The UHS-II support helps it to record 4K video without dropping frames. |
| Samsung NX-1 | A 28MP Back Side Illuminated APS-C Sensor which can shoot at sustained 15 fps at full 28MP resolution (using UHS-II SD cards, of course.) |