TEMPS, SUSTAINED WRITES AND TRUE DATA TESTING
Two characteristics that became very important with the introduction of CFexpress as a mainstream storage medium were temperature and sustained write speeds. We measure temperature by monitoring and updating a Crystal DiskInfo Benchmark while a large 85GB 8K file transfer is being performed. This is the extreme of what one might see in this environment.
The lower the better and the Transcent CFexpress 820 fell just a little short of center yet was cooler than both Lexar and SanDisk CFExpress Type B cards.
SUSTAINED WRITE PERFORMANCE
We determine sustained write performance by transferring a 85GB 8K media folder from the PC to the CFexpress Type B card. This test is vital to those looking at digital storage for high end 4K and 8K video recording. As we have also started testing with the Transcend RDE2 USB 3.2 Gen 2×2 20Gbps Card Reader, we also test with the more traditional Thunderbolt 3 readers to ensure there was no deviation in results. There were not.
The Transcend CFexpress 820 Type B Memory Card didn’t perform as well as the other cards tested to date, with a high sustained write performance of 285MB/s.
In checking Transcends website, we found a chart which spoke clearly to exactly what level of recording the CFexpress 820 was capable of:
As I have a Canon EOS R5 Mirrorless camera, I can relate that the CFE820 is not the best choice of cards for that camera specifically; the chart above confirms this.
REAL WORLD FILE TRANSFER COMPARISON
For our Real World File Transfer Comparison of the world’s top CFexpress Type B cards, we have included all cards that we have received to date. This test is conducted through the transfer of data from one spot on the test drive to another to give us the truest of transfer speed results for that device.
The Transcend CFexpress 820 Type B card fared just where we thought it might, and in line with comparable benchmarks that we have seen thus far.
REPORT ANALYSIS AND FINAL THOUGHTS
The Transcend CFexpress 820 Type B Memory Card is new to the market and capable of reaching its listed specifications of 1700MB/s read and 1300MB/s write data transfer. This kind of speed does not happen within the recording device and is relied on most often when moving data from the camera card to the PC. CFexpress card performance has become very important as of late, however, as it simply means that newer cameras such as the Canon EOS R5 will have certain functions (8K video) restricted and not available if the camera detects that the storage card isn’t capable of reaching a certain sustained write speed. This, after all, is why we have gone to great lengths to include sustained write performance and card temperatures within our reports.
In consideration of this, it appears that the Transcend CFexpress 820 did not fare to well in a certain aspect of results but, all the credit to Transcend, they published clearly exactly what the card is capable of. They created this card for a direct segment of the consumer, photographers and those recording 4K video. This became very obvious when we went to run pricing comparisons of the 820 against other cards and found that this card falls into a segment of value oriented cards and, in fact, was the lowest price of mainstream cards available. The CFexpress 820 was meant for a specific consumer and, from what we are seeing in reviews and ratings, it fares very well.
We don’t think we could finish this report, however, without final mention of the Transcend RDE2 USB 3.2 2×2 20Gbps CFexpress Type B Card Reader. This is a valuable tool to those that have invested in CFexpress type B and it is the first reader we have seen using the USB 3.2 Gen 2×2 interface. Our report of the RDE2 is here.