SanDisk SDHC 45MB/s or 95MB/s, is more speed worth it?

[Deathbynature]

Is it worth buying a SanDisk Extreme Pro 95MB/s SDHC card for the 600D/T3i? Or is SanDisk Extreme 45BMB/s good enough due to hard limitations?
I want to film 1080p at 35fps.

[1%]

There is no hard limitation (except at SD manufacturer). Get the fastest card you can buy, look at sustained write not burst speeds. Unless you don't mind default bit rates.

[Roman]

Where are you videos going to end up?

If on Youtube or Vimeo, your bitrate gets slaughtered anyway so I cant see much advantage to cranking up the bitrate.

And it gets a bit silly if you can only film a few minutes of footage on a 64gig card, both at the time and editing afterwards.

Here's a quick graph I made of audio/video bitrate of what I'm able to record, vs the maximum of how it ends up online:




You can see that even a cheap camera like a ContourHD or a GoproHD is well capable of blowing out the Youtube bitrate... But audio can (potentially) be uploaded at a comparatively better quality with the Canon.

[JasonATL]

To answer the OP's question: if you are asking if 45MB/s is worth it, then Yes. If you are asking if 95 MB/s is worth it, then I'd say no. At least for me, I've not found a need for the extra speed and I'm skeptical as to whether the 600D/T3i would take advantage of it.

I have the 600D/T3i and the SanDisk Extreme (45MB/s) cards are the only ones that I have found to be reliable at recording HD video - I haven't tried the Extreme Pro (90MB/s, but I'm sure they'd be reliable). I've had other mfr's class 10 cards fail (as in, the camera would stop because the card couldn't keep up). I've also used the Extreme's with the bitrate multiplier with no unexpected issues (at high bit rates with audio, in bright sunlight, the camera will stop, but the file usually show a bitrate in excess of 90Mb/s).

With all due respect to Roman's analysis of bitrates, which I found quite interesting, I hope that the point was not to say that we need not acquire at such a high bit rate. I think that you should try to acquire at the best bit rate that is possible or practical and not necessarily at one that is simply suited for the resulting distribution/exhibition bit rate. First, you might have the opportunity in the future to distribute/exhibit at a higher bit rate. More importantly, you will be editing, compositing, and grading your footage, which requires more information to work with than the final render. And, finally, algorithms that get used for compressing for final delivery have the potential to do a better job than on-the-fly compression in-camera and thus, can make more of a given bitrate (they can do worse, too) -- and they are recompressing, losing a generation. In short, the better the image you have to start with, the better the resulting image.

[Roman]

Hey thanks, yes you raise some good points.

However since we have a 4gig limit per video file, the bitrate tradeoff becomes a bit more complex.

If I buy a 128gb card, it doesnt mean I can record at 3x bitrate for as long as a card 1/3rd the size with normal bitrate.

I certainly agree that generally speaking recording at a higher bitrate is better, but for some shots of mine I'll likely be downsizing mine from the factory bitrate to acheive a longer record time within 4gigs.

Even without the 4gig limit it's diminishing gains for recording at a higher bitrate in terms of perceivable quality.

However with the size limit issue you were recording at 100mb per second, being able to record for only ~40 seconds at a time is very impractical.

Regarding the 95mb/s cards, I've been doing a bit of homework into this. From what I can gather the 95mb/s Sandisk cards can only write at that speed when they are in UHS-I mode.

The 600D doesnt support UHS-I mode, it requires running the card at a lower voltage to usual.
So the card is only run in the 'normal' mode at a higher voltage, however fast that may be.
Not sure what this means in terms of how fast it would actually write, I would be interested to see a back to back comparison between the 45mb sandisk card and the 95mb one on a non UHS-I device like the 600D.

I'm looking at purchasing a 32/64/128gb card, and I'd be willing to spend the $$$ on a 95mb/s card if I saw proof of if it's actually capable of being utilised.... And I wouldnt want to  commit to a 45mb/s if a 95mb card could be used above the capability of a 45.

I'd love to see the difference quantified between the 45 and the 95 on the 600D or similar, but I might have to just take a punt on that one.

[1%]

However since we have a 4gig limit per video file, the bitrate tradeoff becomes a bit more complex.

Only have the 30 minute still.

Regarding the 95mb/s cards, I've been doing a bit of homework into this. From what I can gather the 95mb/s Sandisk cards can only write at that speed when they are in UHS-I mode.

Sustained write on these UHS cards is 14-20MB/s. You don't only have to buy sandisk. The patriot card was like 1/4 of the $andisk. 

http://mxmexpress.com/cms.php?id_cms=6

[Roman]

Are you saying that the 4gig limit is no longer present?

Or that the 30 minute limit is no longer present?

Great news either way if so!

I would assume the 4gig limit is still there, since the "video remaining" counter has the option to display how much of 4gb is left?

[InFocusAV]

Are you guys saying that if I was to shoot in broad daylight with my 64gb 45mb/s card with my t4i, i won't be able to record for the full 29:59? I just bought an 80 mb/s SD card thinking I was going to be able to do long term picture bursts and noticed it shot slower outside...

[Datadogie]

I thought you needed Tragic lantern for the 30minuts.

http://photography-on-the.net/forum/showthread.php?t=1232870