SD write speeds concern

Started by cinedude, June 02, 2013, 02:56:00 AM

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cinedude

Hey  guys/gals,

I've been trying to figure out this sd read/write speed thing and it's relation to raw recording.

I've been testing RAW on my Patriot 16GB class 6 sd. It seems to be working great and the bechmark tests have it clocked for about 12MB/s write and 20MB/s read.

I researched sd card speeds and from what I've read, the "extremepro" cards or anything claiming 45MB/s read/write and up, uses UHS technology witch the T2i isn't capable of. I'm wondering if that's correct?

I also recently purchased a Sandisk 16GB class 10 card with expectations of higher write speeds. According to my benchmarks, this card actually writes slower than my class 6 at around 8-9MB/s. I exchanged that one thinking it could be a bad card but sure enough my new card has the same slow speeds.

So what the hell.

I thought the fancier cards claiming 45 and 95MB/s weren't compatible with the T2i but other posters have been showing they're getting much more frames with theses cards...

Audionut

The T2i SD hardware is limited to around 21MB/s iirc.

It makes sense to have a faster SD card (45MB/s or 95MB/s) to ensure that the slowest device in the recording chain is the SD slot in the camera.  Rather then a slower card which will limit recording speed even further.

All SD cards should be backwards compatible.  So faster cards with newer technology still work in older cameras.

cinedude

Quote from: Audionut on June 02, 2013, 03:07:50 AM
The T2i SD hardware is limited to around 21MB/s iirc.

It makes sense to have a faster SD card (45MB/s or 95MB/s) to ensure that the slowest device in the recording chain is the SD slot in the camera.  Rather then a slower card which will limit recording speed even further.

All SD cards should be backwards compatible.  So faster cards with newer technology still work in older cameras.

That makes sense. So these UHS technology cards still boost the speed? That's what I meant by "compatible"

xNiNELiVES

With 12 mb/s write your going to get barely any frames. You need the max you can get with a SanDisk ultra at 30mb/s read and write.

cinedude

Quote from: xNiNELiVES on June 02, 2013, 04:00:50 AM
With 12 mb/s write your going to get barely any frames. You need the max you can get with a SanDisk ultra at 30mb/s read and write.

That's what's so weird, I have a Sandisk Ultra 16GB class 10 which advertises 30MB/s read/write speed. But the benchmark says different.
:(

xNiNELiVES

Quote from: cinedude on June 02, 2013, 04:24:57 AM
That's what's so weird, I have a Sandisk Ultra 16GB class 10 which advertises 30MB/s read/write speed. But the benchmark says different.
:(

Your cameras hardware is listing your SD Card to probably 20mb/s. Most likely around 17.

Drewton

Quote from: cinedude on June 02, 2013, 04:24:57 AM
That's what's so weird, I have a Sandisk Ultra 16GB class 10 which advertises 30MB/s read/write speed. But the benchmark says different.
:(
Same, I only got 12 max. That's why I upgraded to a 95 mb/s card.