PQI SDXC C10 (64 GB)
Taiwanese memory vendor PQI offers a 64 GB SD memory card product called the SDXC C10. The name is derived from the speed category, which is Class 10. This card proves that high-capacity SDXC cards do not have to be high-speed products. Kingston and SanDisk show the opposite, wielding plenty of speed, but more conventional capacities.
So far, this is the only true SDXC card that has reached our test lab, although more and more products are becoming available. The SDXC C10 delivers above-average performance in all benchmarks and is comparatively strong in the random write tests using 512 KB block sizes. Stepping down to 4 KB blocks reveals that you shouldn't run random write operations on a card like this (though the same applies to any of these SD-based products, which really aren't meant for such a workload). Combined read and write operation, in addition to I/O performance, aren't this card's strengths.
This product reaches its peak sequential performance at 22 MB/s for reads and 21.4 MB/s writes. It always maintains at least 12.9 MB/s, which is a modest result. Unfortunately, we haven’t found this card for purchase yet online, and we're disappointed that PQI sent in a piece of hardware that wasn't yet ready for worldwide availability.