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Chris7

macrumors 6502
Original poster
Aug 8, 2008
396
0
Lost in Thought
Shooting RAW only, or RAW + JPEG at a 8/sec burst, with, say a Sandisk Extreme Pro,

How long does it take for the RAM buffer to empty to the card?

Also, the Canon site says about 15 shots RAW and about 6 RAW + JPEG to fill the buffer. Is this what the people here are getting with a 90MB/sec UDMA card?

I should probably also ask, can the camera take advantage of the 90MB/sec cards, or will it write just as fast to a 60MB/sec card?

(I called Canon, who said they do not publish nor have access to the actual write speeds).
 

jampat

macrumors 6502a
Mar 17, 2008
682
0
Check out this guys site, he has put a lot of time and effort into a database that helps with your question.

http://www.robgalbraith.com/bins/camera_multi_page.asp?cid=6007-9784

They don't have the 7D on the website, but the 5DII appears to max out at ~30 MB/s (even though some of the tested cards were rated at 45 MB/s+). I haven't heard of a body yet that can utilize the extra speed from UDMA, but it vastly improves the card to computer transfer times.
 

borrowlenses

macrumors newbie
Feb 25, 2010
5
0
San Mateo, CA
As previously stated the biggest visible benefit with these faster cards is when downloading images, more so then when shooting. However there is a big difference between generic CF and Sandisk Extreme CF for example.
 

wheezy

macrumors 65816
Apr 7, 2005
1,280
1
Alpine, UT
I think that vid debunks the "max out at 30MB/s" myth. I have their 300X card in my 5DII and it's perfect, at 30MB/RAW image I can shoot one, and by the time I'm looking down at my camera the preview is ready. On older cards it's 2-3 seconds just to fully save ONE photo.

So, by watching the video, you can see the advantage of a 600X card.

OH, and coupled with a FW800 Card Reader you can unload those CF's REAL fast onto your computer.
 

iBookG4user

macrumors 604
Jun 27, 2006
6,595
2
Seattle, WA
I use a 60MB/sec card with my 7D and I've found that after taking 16 shots, each at 24.3MB it took 7 seconds to clear the buffer. So the camera wrote to the card at 55MB/sec which is right near what the card is rated at, so it'll definitely write at more than 30MB/sec. But I don't have the 90MB/sec card to compare it to.
 

osin

macrumors 6502
Jun 8, 2008
309
10
New Jersey
As previously stated the biggest visible benefit with these faster cards is when downloading images, more so then when shooting. However there is a big difference between generic CF and Sandisk Extreme CF for example.

Obviously you didn't see/understand the video!
There is one more and huge benefit shooting with these faster cards, the write speed! These cards make a big difference when shooting series of RAW files (8 or 10fps). Buffer clears much faster, allowing to take another series of shots much quicker.
Of course, like it is always the case with photography, it all depends on your style of shooting... :)
 
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