# 5D III - SD card that will write fast?



## Canon1 (Nov 18, 2013)

Currently using SanDisk Extreme Pro cards in my camera. The CF card is rated at 90 mb/sec and the SD card is rated at 95mb/sec.

When my cf cards fill up and i switch over to the sd card there is a huge noticeable difference in write speeds. It seems I am able to burst about half the frames with the SD card before the buffer fills up and I have to wait a few sec to continue shooting. Is there an SD card that someone would recommend that would resolve this problem or is this simply a limitation of the camera or tech. 

That said, is there another brand of card that would allow for more continuous shooting before the buffer fills up? I have always shot with San Disk and had good luck, but willing to try something else if it improves write speed.

Thanks for commenting.


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## Grumbaki (Nov 18, 2013)

If I'm not mistaken 5D3 as a cheapo SD bus that acts as a bottleneck on high end SD.

If so then there's no solution.


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## Mt Spokane Photography (Nov 18, 2013)

The 95 MB/sec number for SD cards only happens in the event that the stars align as follows.
1. The Card must be new or just low level formatted, as soon as it has been used and given a regular (quick) format, it becomes a 20mb /sec Card

2. It must be used in a camera that is enabled for UHS-1, the 5D MK III is not, so that 20MB/sec becomes 10MB/sec.

Do a low level format and that will put the card into new condition and you can get 20 - 30MB / sec with a 5D MK III.

Its a big waste of $$ to buy a UHS-1 card, they depend on a double speed bus to get that speed plus the low level format issue.

The issue with the low level format is that the card can be written to at full speed when it is new and blank or after a low level format.

Once it has been used, a regular format just marks it as being available to erase and write to. The camera must first do a relatively slow erase of a memory block, then write to it, then erase another, and so on. That is a big part of why its slow. This does not happen the same way with CF cards, so you actually get the advertised speed.

Even worse, if you set the 5D MK III to write to both cards at the same time, it will slow to the speed of the SD card.


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## Ruined (Nov 18, 2013)

The 5DIII SD slot does not support 95mbps unfortunately.

Anything faster than the 45mbps card like the one below is pretty much a waste:
http://www.amazon.com/SanDisk-Extreme-Class-Memory-SDSDX-032G-AFFP/dp/B007M54E1M/ref=sr_1_1?ie=UTF8&qid=1384756667&sr=8-1&keywords=45mbps+sandisk


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## Canon1 (Nov 18, 2013)

All interesting stuff. I wish that canon had just installed 2 CF slots. Would have made more sense to me.

I'll try the low level format to see if that helps.

As a follow-up: Do you know the fastest speed CF card the 5DIII is able to fully utilize?

Thanks,


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## Marsu42 (Nov 18, 2013)

Canon1 said:


> All interesting stuff. I wish that canon had just installed 2 CF slots. Would have made more sense to me.



Then guess why the 1dx has dual cf slots while the 6d has single sd :-> ... Canon is really good at deliberate juggling with specs, while the mediocre speed on the 5d3 is probably unintentional while in the 6d canon didn't find it necessary (even with uhs-1 max 40mb/s).



Ruined said:


> Anything faster than the 45mbps card like the one below is pretty much a waste



It's not so much about the max read speed on the card, but cards vastly differ in write speed and how long they can sustain it - for example some 16gb cards are much lower than their 32gb brothers, a micro-sd with an adapter is much slower than full sd even if the cards says otherwise. Be sure to read reviews about the very exact sd card you're trying to buy.


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## docsmith (Nov 18, 2013)

Very interesting. I'll need to reformat my SD card with the "Low" process from here on out. I've run into this and the SD card does make everything very slow. While not ideal, I've taken to saving RAW to the CF card and JPG to the SD card. That has helped, of course, because of the smaller file size of the JPG. I've actually grown to like this system as I can now take the SD card out and share it with friends/family if they want to down load some of my shots before I take the time to process them.


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## adhocphotographer (Nov 20, 2013)

I usually format my cards (CF/SD) in camera.... is that better worse? What is the best way to format your cards?


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## Mt Spokane Photography (Nov 20, 2013)

adhocphotographer said:


> I usually format my cards (CF/SD) in camera.... is that better worse? What is the best way to format your cards?



When you format a SD card in camera, you have a option for low level format. This erases every memory location. It also takes a very long time. Once the SD card has been filled, do a low level for fastest speed writing. It makes no difference for read speed, its write speed that is at issue.

You can format CF cards in camera, but running a full format in a computer occasionally will write to every memory cell and ferret out and bad cells which are mapped out. That prevents you from getting occasional garbled images due to bad memory cells.


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## alexanderferdinand (Nov 20, 2013)

Slow (crappy) speed of the SD interface of the 5D3.
So every card with more write speed then 30MB/s is luxury.

I hate Canons policy of the "cripple- to- fit- in- that- category" policy.


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## Ripley (Nov 20, 2013)

Canon1 said:


> All interesting stuff. I wish that canon had just installed 2 CF slots. Would have made more sense to me.
> 
> I'll try the low level format to see if that helps.
> 
> ...



5Diii does not support UHS SDHC/SDXC cards. There is no SD solution to my knowledge.

Sandisk is great and they just released a faster series of CF cards that would probably interest you...
http://www.bhphotovideo.com/c/search?Ntt=sandisk+160mb%2Fs&N=0&InitialSearch=yes&sts=ma

No guarantees on your burst speed or duration, but a larger size would definitely solve the problem of switching to the SD card.


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## Mt Spokane Photography (Nov 20, 2013)

The UHS-1 spec was released shortly before the 5D MK III was announced. Its very likely that the camera design was already complete and parts on order when UHS-1 parts started becoming available. New tech is coming out all the time, and the camera was already long overdue, and a redesign and obtaining and testing new parts would have delayed it further.


Its not a situation of holding back technology, later cameras all support UHS-1. There is a physical difference, so there is no software upgrade possible.


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## Rienzphotoz (Nov 21, 2013)

Good info ... thanks for sharing.


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## Nishi Drew (Nov 21, 2013)

Wow this is news to me... I don't have any CF cards just an SD to CF adapter for my 5DII, as I have a lot of fast SDs.
I thought I could get away with just using SD cards for a while if I got a 5Diii but rats, guess I'll grab a fast CF after all (need 'em for the RAW video deal anyways)


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## endiendo (Nov 21, 2013)

I use a very fast CF when I need speed. (birds, animals), while having a SD in, to avoid missing shot when CF become full (and pass automatically on the SD to not stop burst shots)

I use many cheap and large SD when I need place and have time. (travel, landscape)


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## wsgroves (Nov 21, 2013)

On a side note Mt. , Can the 5d3 take advantage of the speed increase of the SanDisk Extreme PRO® CFast™ 2.0 cards?


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## ajfotofilmagem (Nov 21, 2013)

wsgroves said:


> On a side note Mt. , Can the 5d3 take advantage of the speed increase of the SanDisk Extreme PRO® CFast™ 2.0 cards?


To date, there are not still cameras compatible with the new cards "CFast 2.0".


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## wsgroves (Nov 21, 2013)

Thanks AJ! I kind of figured it would not take full advantage.


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## Canon1 (Nov 21, 2013)

Ripley said:


> Canon1 said:
> 
> 
> > All interesting stuff. I wish that canon had just installed 2 CF slots. Would have made more sense to me.
> ...



I noticed they just came out with that. This is my thought exactly. Get a larger card that is less likely to fill up on a shoot. Downside on this is that if you lose a card or it corrupts you have more files to lose. This has happened once over the years for me, however filling up a CF card and switching to the SD card happens all the time. And the Slow write speed makes me stop to change out the card. Not the end of the world but annoying none-the-less. 

It will be interesting to see if the 160mb/sec cards improve continuous burst time... or is the limit already based on camera specs. (I use 90mb/sec currently)


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## bvukich (Nov 21, 2013)

SD? You mean the Magic Lantern and emergency failover slot? 

Yeah, it's painfully slow, and there's nothing you can do about it.


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## Mt Spokane Photography (Nov 21, 2013)

wsgroves said:


> On a side note Mt. , Can the 5d3 take advantage of the speed increase of the SanDisk Extreme PRO® CFast™ 2.0 cards?



No. they are totally different, they need different electronics in the camera as well as a different connector. Any kind of upgrade would likely cost more than the camera is worth, and won't happen. The CFAST Card has a SATA interface, needs a SATA controller, and, to top it off, can't plug into a existing SATA port because the connectors are different. A adapter is possible, so those with a external SATA port on their computer might use a simple adapter. Unfortunately, they have stopped putting external SATA ports on PC's, going for USB 3.0 instead.


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## adhocphotographer (Nov 22, 2013)

Mt Spokane Photography said:


> adhocphotographer said:
> 
> 
> > I usually format my cards (CF/SD) in camera.... is that better worse? What is the best way to format your cards?
> ...




Holycow! My SD card is no longer a snail, merely a lame duck! thanks for the info... i was starting to question the use of the SD slot at all!


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## Rienzphotoz (Nov 22, 2013)

adhocphotographer said:


> i was starting to question the use of the SD slot at all!


 ;D ;D ;D


adhocphotographer said:


> i was starting to question the use of the SD slot at all!


Not every image requires blazing speeds ... SD card is a nice back up ... better to have and not need it then to need it and not have it.


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