Just a little interesting but non-important SD card testing. Mostly older ones I have. Mainly been carrying around the following in my neck strap and camera: Lexar Pro 633x (Class 10 / UHS-I U1) x2 Lexar Pro 600x (Class 10 / UHS-I U1) Lexar Platinum II 200x (Class 10 / UHS-I U1) Used to have PNYs and Sandisk, but the PNYs kept cracking at the edges particularly around the lock switches, and the Sandisk (mainly the Micro-SD as they were more available locally than just the regular SD) kept giving problems like memory card error or corrupting the data out of the four or so Ultras and Extremes I had (back when they were 30MB/sec and 45MB/sec rated) Picked up a Promaster Rugged, normally I wouldn't try a Promaster mainly cuz they just seem like a cheap brand to me, but the 'promise' of being more durable, and having higher write speeds along with a 48 hour replacement guarantee if it fails made me want to least try it. So when I got home to test the card in my Lexar Pro USB 3.0 SD reader (a long while back I got it because I figured a dedicated SD reader thru USB 3.0 would give me the best transfer results to the computer, and it does for the most part, "Workflow SR1 SD/UHS-I/USB 3.0 Reader"), and nice enough the promaster does transfer consistently somewhat to the rated speed (the write speed is more accurate than the read) My really loose testing is basically computer-only: Each card formatted in my Olympus E-M5 (mk1) Plugged into my Lexar USB 3.0 SD reader plugged directly into a USB 3.0 port A simple "small pattern test" done with CheckFlash 1.16.2 The last three on the list pretty much never see usage anymore so they just kind of stay home as a 'backup'. Promaster Rugged 16GB UHS-I Class 3 / U3 Labeled : 99 read, 80 write Tested : ~83 read ~79.8 write Note : holds both read and write speed consistently within 0.01MB/sec Lexar Pro 633x 16GB UHS-I Class 1 / U1 (two copies of this) Labeled : 95 read, 10 write (as per lexar's site) Copy 1 Tested : ~82.7 read ~20 write Note: read held consistent withing 0.05MB/sec, write started at 13, ramped to 20 near 15% dropped down to 18 around 50% Second Copy Copy 2 Tested : ~83 read ~20.15 write Note: holds write speed rather consistently within +/- 0.03MB/sec from start to ~75% dropping to about 17MB/sec to end Lexar Pro 600x 16GB UHS-I Class 1 / U1 Labeled : 90 read, 60 write Tested : ~82 read ~45 write Note: write starts at 14, quickly jumps to 45 MB/sec climbs about 0.01 per second as the test continues Lexar Platinum II 200x SDXC Class 10, UHS-I Class 1/U1 64GB Labeled: 30MB/sec read, Write speed unspecified and stated to be "lower" Tested : ~44 read ~32 write Note: write starts around 35, drops to 20, then back up to a substained 32 (+- 0.1) from 10% onward Sandisk Ultra Class 10 UHS-I 32GB Labeled 30MB/sec (no separate read/write rating) Tested : ~42 read ~12 write Note: Used in my little Olympus TG-630 point and shoot. Write starts around 11.7, hits 12 around 20% and slowly increases in 0.01 increments to end, peaks around 12.51 PNY Professional Class 10, no UHS-I rating 16GB Labeled : 20Mb/sec ** (assuming for both read/write on the label) Tested : ~22 read ~20 write (write starts around 20, increases slowly to about 21 at 25% and holds from there) Note: The PNY is mainly a at-home backup, I've had hit/miss issues with PNY, so it just sits around but not as bad as Sandisk Ultras and Extreme SD (mainly microSD in adapters which seems to be what is more commonly sold locally) giving me card errors or just ending up corrupted. Sandisk Ultra MicroSD 16GB UHS-I Class 1/U1 in PNY MicroSD Adapter Labeled Unknown but I beleive it was the same 30MB/sec as the Ultra above purchased around same time Tested : ~38.7 read ~13 write Note: Starts around 6, jumps to 12.9 by 20% and holds there teetering around 12.98~12.99. the provided sandisk adapter kept causing memory read errors in the past. Eye-Fi Pro X2 8GB Class 6 Labeled : Unknown read, Minimum 6MB/sec write speed Tested : ~19.5 read ~16.7 write (write holds rather consistent within 0.01 from start to end) Note: rates hold rather consistent from start to end, the rates are halved when using the Eye-Fi reader (as not all card readers work with the eyefi card) Rarely ever used anymore, too slow for my preference of raw files, and rather have a larger card in the point and shoot. Comments What I found interesting is that my 'newer' Lexar Pro cards are half the write speed of the previous 600x series, and are rated even worse, going from 60MB/sec to 10MB/sec in the newer "professional" model, while having a higher read speed advertised on the new one being the same tested (perhaps the USB 3.0 reader caps around 85). But I guess that may explain their competitive price. On the plus side though, the Lexar never gave me any problems, no memory card errors or corruption, just works. Wasn't expecting the Sandisk Ultras to be the worst on the write speeds of what I have, but course they are older. But still performed worse on write than the Eye-Fi card (which from my experience seems to slow down when in camera due to the Wifi capability). While I can't seem to find any official numbers, it would seem that the top write speed of my E-M5 isn't going to be any higher than 28~30MB/sec with the fastest card available at the time (ie: Sandisk Extreme Pro 95/90). So anything that can stay consistently over 20 on the write may seem just fine to me either way. So yea... my little 'quick' testing out of fun and curiosity might come in handy for someone else. The promaster will probably end up being my main-in-the-camera card, followed by the older 600x Lexar, and if I plan on doing a Timelapse, swap over to the Lexar 64gb, with the other two 16s just in case murphy's law kicks in and I encounter a card error on the screen (Which is why I carry more than two now since the sandisk kept doing that to me).