RedIris Loc: MN, USA

The best cards that match what they say their speeds are; are SanDisk higher speed cards. I don't know the names of them.
The megabyte speeds are usually the top speed they can transfer data.... between the card and imported medium (hard drive). It doesn't necessarily mean the speed it can function at inside your camera.

Here is a comparison on different cards.
http://thewirecutter.com/reviews/the-best-microsd-card/

http://www.androidpolice.com/2013/07/09/quick-hands-on-sandisks-new-extreme-class-microsdxc-cards-are-really-really-fast-with-benchmark-results/

http://www.pcmag.com/article2/0,2817,2407326,00.asp

Royalruler Loc: Rancho Cucamonga

I think the path that the images take is sensor to buffer then buffer to your card. So the speed between the sensor and buffer is what determines the number of images per second. Also the size of your buffer is a factor if your buffer fills up it would slow your frames per second.

Wall-E Loc: Phoenix, AZ

Remove the SD card!!!!!

Canon, in it's infinite wisdom, has a relatively slow SD card slot, AND cripples the CF card slot to that same turtle-like speed when an SD card is present. So, you can't take advantage of a super-speed CF card if you have ANY SD card inserted. Incredibly Stupid!!!

Cameoblue Loc: British Columbia Canada

With the 5D3 there are Basically 4 different settings in the camera to record to your cards. See chapter 4 in your manual.

1. Standard- Images will be recorded to the card selected with [Record/play]
2. Auto switch card- Same as with the [Standard] setting, but if the card becomes full, the camera will automatically switch with to the other card to record images. When the camera switches to the other card, a new folder will be created automatically.
3. Rec. Separately- You can set the image-recording quality for each card (p.119). Each image is recorded to both the CF and SD cards at the image-recording quality you have set. You can freely set the image-recording quality to .....(what ever you wish RAW, JPEG, etc)
4. Rec. to multiple - Each image is recorded to both the CF and SD cards simultaneously at the same image size. You can also select RAW+JPEG.
!! When [Rec. separately] is set, the maximum burst will decrease greatly (p.121).

The above has been quoted from the 5Dlll manual. So Wall-e is partially correct only if option # 4 is selected.

Also see page 121 in your manual, it will list Maximum Burst rates according to your camera settings. The quality of your CF or SD card works in conjunction with your camera setting to get maximum rate. You can not get past Maximum no matter what card you use but you can get variables of Minimums depending on quality of your cards. Clear as mud??

How about the short version. It's like, a chain is as strong as it's weakest link, so your camera is as fast as it's slowest circuit (which in this case is in the camera not the card).

RedIris Loc: MN, USA

BUT.... the faster card you use, the better results you're going to get.
If you use the faster card, Extreme SDHX, you'll be more likely to get the top speed out of your camera, whatever that is and depending on your camera's settings.

SharpShooter Loc: NorCal

Birdpix, you are correct. My info was probably useless to the OP.
My apologies to the OP.
SS

Wall-E Loc: Phoenix, AZ

Wrong. Having ANY SD card in the slot and ANY recording mode WILL cripple the available CF speed.
http://www.borrowlenses.com/blog/2013/01/tip-optimize-canon-5d-markiii-write-speeds-avoid-sd-cards/

joer Loc: Colorado/Illinois

When the speed is quoted its usually the read speed. The write speed are always slower. There may be little difference in the write speed between the cards or the camera's threshold has been reached.

Joelbarton87 Loc: Hereford u.k

Please read the post properly i removed the sd card

Wall-E Loc: Phoenix, AZ

I apologize.
Your are correct.
My bad.


Check your manual.
I believe it says that you can only get 13 RAW shots in the buffer.

Joelbarton87 Loc: Hereford u.k

ok thanks