EOS 5D Mark IV Do I need to use a CF card?

[kaphoto]

I just ordered a 5D Mark IV after using a 60D for the last 5 years (I’m not ready for mirrorless yet lol) but I’m confused about the memory card situation. Can I use my regular memory cards without using a Compact Flash card as well? What is the purpose of the CF? This might be a dumb question but I’m not sure about the answer! Lol

[deebatman316]

You can just use SD Cards alone in the camera. The whole point of Dual card slots is for redundancy. The CF interface offers faster communication speeds over the SD interface. I’ve been using CF cards since my EOS 40D. I personally have my EOS 5D Mark IV set up to record to both cards at the same time. Also since you’re coming from the EOS 60D any Canon brand EF-S lenses won’t mount at all. 3rd Party APS-C lenses will but will cause vignetting. Or even worse damage to the reflex mirror. Only use Canon brand EF lenses or 3rd Party lenses designed for Full Frame cameras. I would not invest in extremely high capacity memory cards such as 128GB or 512GB. I use multiple smaller 64GB cards in my camera. Set up to record to both cards simultaneously. 

[Peter]

With 5D IV you can get something like 130 MB/s with CF and 90 MB/s with SD.

[AtticusLake]

First off, there's no such thing as "regular memory cards".  Memory cards come in various types, like SD, CF, CFast, CF Express, etc.  Even within these there are different variants.  SD cards for example have a speed rating, like "v60", which tells you how fast they are (in mega-bytes per second; multiply by 8 for mega-bits per second).  (Ignore the trash marketing speeds printed on the card.)

Bear in mind that the speed you get is the MINIMUM of what the card and the camera can handle.  With the 5D, I believe the SD card interface is UHS-I, so there would be no point in plugging in a UHS-II SD card -- it will only be able to operate with UHS-I speeds,

To answer your question (at last 😉  ) CF cards should generally be faster than SD cards.  SD is the consumer-grade, cheap-and-cheerful option.  You didn't say if you're shooting video, but if you are, you may find that the top video quality modes only work with CF cards.  If you're shooting stills, you may find that burst mode shooting is faster or goes for longer on CF cards.  if you don't care about these things, you might save money by using SD cards -- although fast SD cards are insanely expensive these days.

Hope this clears things up a little.  If in doubt, check out the manual.  You may find page 356 helpful.