Does it hit the marketed throughput? No
. What’s the actual formatted capacity? 128.83GB
. More details below. Also, you can find more information on this review here: http://www.grahamclarkphoto.com/review-sandisk-extreme-128gb/Use Cases
The SanDisk Extreme product line is second fastest in the lineup, with the Extreme Pro clocking in nearly twice that or perhaps more at 90-95MB of advertised I/O. That's nearly twice the speed! However, the Extreme Pro does not have a 128GB capacity, so this is the only option for hitting that capacity range at the moment. For 95% of all use cases involving shooting images from camera to card, the Extreme is above spec, including 30-minute HD1080p footage. Shooters who might have this card are:
Action Sports Photographers
Astrophotographers (and time-lapse photographers)
Anyone doesn't to have more than one card
All speed tests were on run on a 2013 MacBook Air internal SD card slot (450/450mb SDD 6gb/s), which is an interface on the main logic board so it doesn't adversely affect the tests results. Here is a disk whack speedtest run on Blackmagic Disk Speed Test: https://vimeo.com/60428348
35.5MB write, and 37.8MB read speeds are a bit below the advertised 45MB/sec, but still good for nearly all types of shooters. The average SD card speed is roughly half this, where normal falls somewhere between 16-20MB/sec. A finder block copy transfer of 500MB had approximately +3 MB on read/write.Formatted Capcity - 127.85GB
The actual camera formatted capacity of the SanDisk Extreme 128GB SDXC card is 127.85GB. Awesome!Overall Impressions
For still shooters, the SanDisk Extreme 128GB SD card is now the last card you'll probably need for the next 3-5 years. If you shoot 30MB RAW files, you can shoot 4,369 RAW images until this card becomes full. If your RAW images are 50MB each, you'll max this one at 2,621 images. 80% of cameras fall under 30MB per RAW file. For video shooters, multiple 30-minute clips can be shot in sequence with just a short break in-between.
Wether you're going to be shooting stills or video, get the SanDisk Extreme 128GB over the Transcend 128GB SD TS128GS. It's only $30 more . For any capacities lower than 128GB, I recommend the Transcend as the price point as it's much less expensive and the speed/reliability is excellent.
If you have any questions or comments please don't hesitate to leave a comment below!