Leica M startup delay

Most mid-level or better digital cameras have a negligible startup delay of around 0.2 seconds. Alas, Leica M startup delay is often measured in seconds, which may be a problem for some shooters and scenarios. Photographers on Leica related forums and blogs posted various suggestions regarding this problem:

  • 64GB cards give discernibly faster wake up time
  • It is not the capacity of the card, but the controller that matters. SDXC cards perform better than SDHC cards
  • Reformatting the card with SD Formatter significantly improves the startup delay

This post compares different sizes, different types of interface and looks at effect of reformatting the card with SD Formatter with several specific SD cards.

Used cards

Type Capacity Nominal speed Technology
Lexar Professional 600x 16GB SDHC UHS-I 16GB 90MB/s SDHC
Lexar Professional 600x 64GB SDXC UHS-I 64GB 90MB/s SDXC
Lexar Professional 2000x 64GB SDXC UHS-II/U3 64GB 300MB/s SDXC
SanDisk Extreme 16 GB SDHC Class 10 UHS-1 16GB 45MB/s SDHC
SanDisk Extreme Pro 32 GB SDHC – UHS Class 1 32GB 45MB/s SDHC
SDHC_16GB_600x SDXC_64GB_600x Pro_2000x_SDXC_64GB_wRdr sd-extreme-16 sd-extreme-pro-32


The measured startup delay time is from OFF to exposure and the procedure was like this:

  1. Switch the camera off
  2. Hold down the shutter release button
  3. While holding the shutter release button, switch the camera on and start the stop watch at the same time
  4. Stop watch were stopped when the camera made an exposure

Each card was measured three times and the posted times are averages calculated from the tests. This is supposed to be the worst case scenario; when the shutter button is hit while the camera is in standby mode, the times are shorter (but too tedious to measure).

Test results

Average Leica M startup time with various SD cards

Final thoughts

SD Formatter

It is my experience and it was reported elsewhere that SD Formatter halves the startup delays with some cards, but it appears that with the Lexar SDXC 600x and 2000x the improvement is only around 7%.

Nominal speed

The 2000x SDXC card provided 14% faster startup than 600x SDXC card of the same size and type. The 2000x card was 3x more expensive and provided approximately 1% of improvement per $5.50


The SDXC cards were apprpoximately 19% faster than comparable SDHC card.


Lexar Professional 600x 64GB SDXC UHS-I seems to have pretty good performance and is not very expensive.

At the time of this writing, Lexar Professional 2000x 64GB SDXC UHS-II/U3 is only a bit faster, 3x more expensive, but provides 3x faster download to computer using the included USB3 card reader.

See also: SD card to computer performance.


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