# What memory card do you recommend for the new Canon 70D?



## Strobe the globe (Aug 29, 2013)

What memory card do you recommend for the new Canon 70D? Just wondering if I need to upgrade from a San Disk 30GB Class 10 (45MB/sec).


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## Hardproducer (Aug 29, 2013)

Strobe the globe said:


> What memory card do you recommend for the new Canon 70D? Just wondering if I need to upgrade from a San Disk 30GB Class 10 (45MB/sec).



The movie stream on FullHD on 70D is 235MB/min = 3,91MB/sec
So your 45MB/sec is more than enough!

On the other side:
I don't know how it's done with the 7 FPS for Stills... RAW is like +/- 25mb each image. so 7x25=175 MB/s????
Well thats seems to be impossible... So i think thats why continuous shooting has a limit of 16-18 images.
After taking a series of pictures the camera creates the files at end. And will take a while before you can shoot again.


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## GmwDarkroom (Aug 29, 2013)

Until tests come out or you run the test with various memory cards, it's hard to say, but the 6D is a similar setup: http://www.dpreview.com/reviews/canon-eos-6d/12 (see the "Continuous Shooting and Buffering" section).

That test suggests there are benefits to the 90MB/s cards.

Given that at 7fps and 15 shot buffer, you'll have ~2 seconds of burst and if it becomes a problem using the 45MB/s card, you could probably see benefit from a faster card.


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## Famateur (Aug 29, 2013)

It's my understanding that your card's speed won't affect the maximum burst as that's a function of the buffer in the camera. So whether you have a slow card or a fast card, the camera should be able to do the 16 RAW (or whatever the advertised limit is) by filling up the buffer.

Where the benefit of a faster card comes into play is the recovery time once that buffer is filled. The faster the camera can write those files to the card and empty its buffer, the sooner you'll be able to shoot another burst. You don't even have to fill the whole buffer for this to apply. For example, you might shoot a five-shot burst, and then need to shoot a 16-shot burst a second later. With a slower card, those first five shots might not have been moved from the buffer to the card in time to accommodate your next burst.

If I anticipate using the burst mode a lot, I'd upgrade the card to the fastest I could get. If not, I'd be happy with the card you have. Of course, keep in mind that I'm not an expert and you're getting what you pay for with my input.


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## Mt Spokane Photography (Aug 29, 2013)

A Class 10 UHS-1 card will write at 10mb/sec, the 45mb/sec is read speed. 5MB/sec is often more typical for writing with older non UHS-1 class 10 cards. That means it should work, so wait and try it before buying something.

If you do buy a new card, be sure its a UHS-1 compatible. The write speed is often but not always faster with UHS-1. That is because the bus speed is twice as fast, so as long as the card can erase used blocks and write to new ones fast enough, the write speed will be faster than the Class 10 spec of 10MB/sec.


Note: A new card is completely erased and will write very fast. However, once its filled and formatted, the camera can no longer write to it without first erasing the block to be written to. This is a slow process that only applies to SD cards. Buyers test a new card and are happy with the speed, not realizing that the 2nd time they fill it that it writes very slowly.


You can restore a SD card to new condition by doing a low level format. That's a long process and can be frustrating. That's why I recommend buying the fastest SD UHS-1 card from either Lexar or SanDisk.


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## GmwDarkroom (Aug 30, 2013)

Famateur said:


> It's my understanding that your card's speed won't affect the maximum burst as that's a function of the buffer in the camera. So whether you have a slow card or a fast card, the camera should be able to do the 16 RAW (or whatever the advertised limit is) by filling up the buffer.


I wasn't quite clear on that. I didn't mean that the card would affect how many frames you get in burst, but how fast it clears.

Though the 5D3 is affected -- according to Canon -- by memory speed for how many frames you can get in a burst.


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## Famateur (Aug 30, 2013)

GmwDarkroom said:


> Famateur said:
> 
> 
> > It's my understanding that your card's speed won't affect the maximum burst as that's a function of the buffer in the camera. So whether you have a slow card or a fast card, the camera should be able to do the 16 RAW (or whatever the advertised limit is) by filling up the buffer.
> ...



Gotcha.


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## GmwDarkroom (Aug 30, 2013)

Also, I just saw that according to Bryan over at The Digital Picture he's getting 20 frames per burst using a fast SDHC card.

Something to consider.


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## Famateur (Aug 30, 2013)

GmwDarkroom said:


> Also, I just saw that according to Bryan over at The Digital Picture he's getting 20 frames per burst using a fast SDHC card.
> 
> Something to consider.



Interesting. Sounds like there are some things for me to learn here. And 20 FPB? Cool!


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## gtog (Aug 30, 2013)

Strobe the globe said:


> What memory card do you recommend for the new Canon 70D? Just wondering if I need to upgrade from a San Disk 30GB Class 10 (45MB/sec).



A seemingly simple question, most likely expecting a relatively simple answer, but the details get messy.

The Class 10 rating of your current cards means that the card, in a non-fragmented state, is capable of sequential reads and writes at a minimum of 10MBs and applies to the Normal and High bus speeds. A card that also supports the Ultra-High Speed I (UHS-I) bus (speeds 100MHz and 208MHz) also has its own class designation -- the "U" with the 1 inside also indicates a 10MBs minimum. These speed class ratings are defined in the SD standards and stored in the card so the host devices (eg cameras and card readers/computers) can read them and proceed accordingly.

Maximum speeds are left to the manufacturers to claim (what could go wrong there?) and sometimes reflect read speeds, sometimes write speeds, occasionally both. In any case you need to dig somewhat to find out which. Manufacturers could really be more forthcoming and consistent.

One more item if your largest current card is SDHC. SDHC maxes out at 32GB. For larger than 32GB up to 2TB, you are looking at SDXC cards, which have the same speed classes and bus speeds as SDHC, so all that still applies (but not true when you get to UHS-II which haven't hit the market yet), but instead of being formatted FAT32, they use the exFAT file system (developed and patented by Microsoft). If you are on an up to date Windows 8, 7, Vista SP1+, or XP with KB955704 applied, you are ready to go. Even the latest Macs support exFAT (starting with OS X 10.6.5?). The problem is Linux and the Microsoft patents. If you are using Linux (or other *nix) exFAT is not supported. Therefore with Linux you can either not go larger than SDHC's 32GB or you can re-format your SDXC with FAT32 (which could potentially introduce problems to the card and / or host device as it does violate the standard).

At least for the 70D, Canon has said it supports SD, SDHC, and SDXC as well as UHS-I. (Of course more detailed info on what speeds it can support within those standards would be appreciated.)

I would recommend SDHC UHS-I and SDXC UHS-I cards (with the SDXC/exFAT caveat above). The number of GB depends on your shooting preferences and budget. Claimed max speeds likewise -- more important if you often shoot high speed bursts for sports or BIF, not so much for landscapes.

Greg


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## dgatwood (Aug 30, 2013)

gtog said:


> The problem is Linux and the Microsoft patents. If you are using Linux (or other *nix) exFAT is not supported.



You're a few months behind. exFAT has been supported through FUSE for a long time, and Samsung released a native exFAT module in July. Mind you, I haven't tried either of them, but they exist, anyway. 

Alternatively, most (if not all) Canon cameras support the Picture Transfer Protocol, so even if you have no exFAT support, you should be able to transfer pictures from them over USB, albeit more slowly, using gPhoto or other PTP-based tools.




gtog said:


> Therefore with Linux you can either not go larger than SDHC's 32GB or you can re-format your SDXC with FAT32 (which could potentially introduce problems to the card and / or host device as it does violate the standard).



I doubt you'll run into any problems in such a configuration as long as you work within the 4 GB maximum file size limit (mainly a problem for long video recordings). That said, I would stick with exFAT and just find other ways to deal with it.


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## gtog (Aug 30, 2013)

@dgatwood -- you are correct, good catches.

I was thinking of full native kernel support and ignored the FUSE user mode support (would allow read and write, but not format as I understand it). I had also missed this summer's leaked/released Samsung native kernel exFAT module kerfuffle (Thanks!). I doubt the lawyers are out of a job yet on that plus I suspect it is a little too soon to see it in a major Linux distribution. I smacked into this issue recently as an Ubuntu 12.0.4 LTS user trying to use a 64GB SDXC card and wanted to alert others of a possible, even likely issue. Had not considered the PTP option -- I have been using card readers.

As for the comment regarding SDXC re-formatted to FAT32, that was influenced by the Amazon.com listings for the SanDisk microSDXC UHS-I 64GB cards which state "Compatible with microSDXC UHS-I enabled devices; Reformat into file system other than exFAT may cause instability". I have since briefly checked the SanDisk website and did not see a similar caution. Like you, I think one would probably not encounter a problem, but it is outside the SDXC spec and I would also try to stick with exFAT and deal with it in other ways.

Time to look into FUSE exFAT, PTP, and gPhoto!

Greg


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