Lexar 1000x and UHS-II Updated

In the interest of experimentation, I ordered a 32GB Lexar 1000x card (almost all of my SD cards are all SanDisk, with a couple of Sony and Lexar cards in the mix). 

Put the card in the camera, select Format and bingo: "Cannot format memory card. Card may be defective. Insert another card.”

Pop the card out, put it back in: I’m able to shoot with the card. Haven’t had a repeat of a card defective message yet, but remember, users are reporting that this is intermittent. 

So a test: shoot a burst until the buffer fills (at current camera settings that was 23 shots):

  • Taped — 24:53 seconds to clear buffer
  • Untaped first attempt — 32.35 seconds to clear buffer
  • Untaped second attempt — 24:00 seconds to clear buffer


Indeed, repeating the test many times I got variable performance, even after doing the obvious thing and using a contact cleaner on the card pins. Almost all of the attempts with UHS-I active on the card would be about 24 seconds, but every once in awhile I’d get a longer result. Likewise, most attempts with UHS-I disabled via tape were also in the 24-25 second range, but sometimes (rarely) I’d get a longer result.

I then rummaged through all my cards and found a 128GB Lexar 1000x UHS-I card I’d been using in my video gear and tried it: same results.

Okay, how about a SanDisk Extreme 80MBs card that’s not UHS-II? 26 seconds. but I’m starting to wonder if the D500 is actually UHS-II enabled. In other words, does it take advantage of the faster possible speeds of UHS-II? Not sure, but I’d angle towards and answer of “no" at the moment.

UHS-I had two variations, one of which would max out at about 50MBs (100Mhz clock) and another that would max out at 104MBs (208Mhz clock). 

UHS-II should transfer at a full speed of 156MBs if it’s active, and can attain double that if data is one-directional (half duplex). 

The fact that I’m not seeing a significant difference between an 80MBs UHS-I card and a supposed 150MBs UHS-II card in the D500 seems to indicate that it’s SD slot isn’t at all optimized for UHS-II. In other words, Nikon’s “UHS-II compatible” is accurate: a UHS-II card works, but I’m not seeing any clear advantage to using one (see below)

I have a lot more testing to do, though. This guess is based on only two card samples. 

Update: Nikon’s new approved memory card page says “The camera [D500] supports UHS-I”

The previous version of this article identified the Lexar 1000x card as UHS-II compatible. My mistake; it isn’t exactly a high-speed UHS-II card. I’ve now substituted a known high speed UHS-II card into my testing, thus the strikethroughs and update.

Now that I’ve tested one of the top UHS-II cards (a Toshiba Exceria labeled 240MBs write) I can clearly see that the D500 seems to be achieving better than expected UHS-I speeds with at least one card. On the other hand, it’s not achieving the top speed I’d expect from UHS-II support, as the Toshiba card is maxing out at about 140Mbs in the camera. Total number of frames to buffer full is also better on this card than the Lexar 1000x, by the way, by at least 50%. 

Some of the problem is that I don’t think that the marked speeds on cards are particularly accurate representations of what a card can do. Part is that the camera makers don’t necessarily put parts into the cameras that maximize performance in writes, probably because there are other factors that bottleneck the throughput bandwidth. 

So, tentative hypothesis: if you want maximum performance out of the SD slot on the D500 you’re going to need a UHS-II card marked with a very high write performance spec (>180MBs).  

Now, as for the Lexar SD card issues. I’m starting to suspect file fragmentation. The reason why reformatting with the SD organization’s formatter works for some is that it’s putting down a better file structure for large data (true of 64GB cards with certain options turned on in the formatter). What I suspect is that the cards triggering errors are all formatted in FAT32, not exFAT.  So, if you’re experiencing issues with the Lexar cards, try a low level formatting in exFAT and see what happens. If you don’t know what that means, you’re getting into a realm where too little knowledge can cause more problems than it fixes. 

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