Bests & Worsts Reviews from Amazon

As of the end of May 2013, the Sony 32 GB SDHC R40 is on sale for under $20, so the card is a bargain in light of its reasonable performance specifications. Note however that to maximize the performance of this card, your host device must be UHS-1 compatible, which means many older devices will find this card to be a poor performer. In newer devices, this is a good card-reasonably fast, waterproof, and with recovery software (if needed) available for download. After receiving this card, I tested it against a bunch of other SD cards in my personal inventory. Note that there is some room for error (due to hand/stopwatch reaction time). Nevertheless, it's a good relative overview. I tested using a UHS-1 capable reader and files of known size. Here's a summary of the results: Sandisk Extreme SDHC (45 MB/sec label) READ: 44.9 MB/sec (with bursts above 50 MB/sec) WRITE: 34.32 MB/sec Sony 32GB SDHC UHS-1 R40 (the card being reviewed here) READ: 39.61 MB/sec (with significant initial burst of over 100 MB/sec) WRITE: 19.07 MB/sec PNY "Professional" 16GB, (20 MB/sec label) READ: 14.78 MB/sec WRITE: 20.74 MB/sec Patriot LX Class 10 16GB memory card (from Fry's Electronics) READ: 11.15 MB/sec WRITE: 19.79 MB/sec Sandisk Ultra, with UHS-1 label READ: 36.76 MB/sec WRITE: 10.67 MB/sec And just for fun--here's what a number looks like for an older compact flash with UDMA controller: Sandisk Extreme IV 4 GB compact flash READ: Not tested WRITE: 33 MB/sec So, as you can see, while this Sony card is not the fastest performing card out there, it's performance is still quite good in the latest gear. Also, a quick word about video and transfer rates. Digital video is recorded in "megaBITS" per second, while these cards are speed rated in "megaBYTES" per second. That makes it a bit confusing. At the moment, digital SLRs from the factory are at about 24 up to 100 megabits/second in terms of their video rate. To convert bits to bytes, divide by 8...so that becomes 3 MB/sec to 12.5 MB/second. For most digital SLRs out there, even the Sandisk Ultra is fast enough for video, but if your camera has a high bitrate option, this Sony has enough headroom for sustained file writing. The Sandisks are still king of the mountain, but they do cost more. Sandisk has long underrated their higher end cards; even older Sandisks are often faster than newer cards from other makers (like the older compact flash example above). If you absolutely need the higher performance, go with the Sandisk Extreme or Extreme Pro, but you'll pay for it. From my own numbers, I'm comfortable with the Sony for day to day use for my D800. If I really need speed though, I'm going with compact flash over SDHC.