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TEMPS, SUSTAINED WRITES AND TRUE DATA TESTING
TEMPERATURES
Two characteristics that became especially important with the introduction of CFexpress as a mainstream storage format are operating temperature and sustained write performance.
To measure temperature, we continuously monitor the card using CrystalDiskInfo while performing a large 85GB 8K file transfer. This represents an extreme workload designed to push the card to its thermal limits. The temperatures reported are the highest values recorded at any point during testing, with the card being monitored continuously throughout the entire transfer. As such, these results reflect worst-case operating conditions rather than typical day-to-day use.
The ProGrade Iridium CFExpress 4.0 Type-A 512GB memory card reached a temperature high of 69°C. This may seem high, but when considering this cards small size and the speeds we are pushing through it, this is expected.
SUSTAINED WRITE PERFORMANCE
We determine sustained write performance by transferring a 85GB 8K media folder from the PC to the CFexpress Type-A card. This test is vital to those looking at digital storage for high end 4K and 8K video recording.
The advertised sustained write performance for the ProGrade Iridium CFExpress 4.0 Type-A 512GB memory card is 1.5GB/s and things fell just below that. This is also the highest result we have had to date.
REAL WORLD FILE TRANSFER COMPARISON
Our Real World File Transfer 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 ProGrade Iridium CFExpress Type A 4.0 512GB memory card placed first ahead of both the Lexar and previous Gen ProGrade Type A cards.
REPORT ANALYSIS AND FINAL THOUGHTS
While I’m not a Sony user, it’s hard not to recognize what ProGrade has accomplished with its CFexpress Type A 4.0 Iridium memory card. It doesn’t quite reach the performance levels of today’s fastest CFexpress Type B cards, but that’s hardly a fair comparison. Type B cards are nearly twice the size and considerably thicker.
For a storage medium this compact, the Iridium delivers exceptional performance, particularly where it matters most: sustained write speeds. Simply put, it sets the benchmark for what is currently possible in the CFexpress Type A form factor.
With throughput speeds reaching up to 1,800MB/s and sustained write speeds that we validated at 1,400MB/s, there simply isn’t another CFexpress Type A card on the market that can match its performance.
The only real downside is a modest increase in pricing, driven largely by the global NAND flash memory shortage as AI demand continues to consume manufacturing capacity. It wouldn’t be fair to let this influence our final rating, however, as these market conditions are well beyond ProGrade’s control.
If there’s one area where we’d like to see ProGrade improve, it would be extending the product warranty to five years. That small change would make an already outstanding product even more compelling.
This memory card is well deserving of our Editor’s Choice Award as it truly is the world’s fastest Type A sustained write memory card in the world.
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