EOS M Raw Video/SD write speed Problems

Started by Gniesbert, December 25, 2023, 04:43:26 PM

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Hi there

My EOS M tellls me that the write speed of my SD card is too slow to record Raw.
Ive done some SD Benchmarks and it tops out at 20.8 mb/s, which is kinda weird, cause i use a SanDisk EXTREME PRO 95 mb/s 64gb with theoretically 90 mb/s write.
Ive tried Multiple ML releases, and all have the same write speed problem, while everything else works fine. Ive tried another SD card this time a SanDisk EXTREME 90 mb/s, same Problem there.

Does anyone know how i could fix the Problem?
thx in advance
and Merry Christmas!

Walter Schulz

If overclocking mode is incompatible with card you will see numbers in the 20 MByte/s region. It is a fallback mode.
Try to lower oc frequency to 192 MHz or 160 and give it another run.
Some SanDisk require Access Mode SDR50 instead of SDR104 to run properly. You will find this setting in oc sub menu.

I cannot test my only Extreme Pro 95 MB/s because card has a plastic piece missing and EOS M denies working with it.

If your problem persists you should switch to cards proven running fine in highest oc mode. See https://wiki.magiclantern.fm/cards_240mhz
My price/performance recommendation: Samsung EVO Plus 256 GB (2021 edition). The white one.


I tried all the different combinations, none of them work. Ill get one of the EVO plus and see if that works.

Walter Schulz

Are you sure to have restarted cam after changing settings?



Maybe you got a fake sd SanDisk card 😦 because it should work more than 20 if you activated the hack and restart the cam

Walter Schulz

Doesn't have to be fake to fallback to 20 MByte/s.
I have a very, very fast card specified for 130 MByte/s write. In compatible cardreaders this one can reach 156 MByte/s.
No luck in any Canon cam when overclocking is active. 20 MByte/s with oc, around 40 without.

We have no reliable reports for Extreme Pro 95 MB/s with latest sd_uhs.mo.