Sandisk Memory Cards

[bob williams]

I am open to suggestions as I was expecting 40-50 MB/s and got 16-18 MB/s.

Brant, One thing Dawned on me---Maybe we are mixing apples and oranges and expecting the same results:


On my test, I only timed 15 seconds andwas getting some significant buffer lag by the end of the test.


On your test, you did 20 seconds, so I can only assume you exprienced the same the last few seconds of the test.


Now your total calculationsmost likley included those "slow moments" when you are only getting one or two shots off per second


With your test being 20 seconds long you had 5 more seconds of "slow" to throw into your calculations, which would reduce the overall calculated speed.


My suggestion is for two or three of us to use the exact test parameters (or as close as possible) and then see what happens---My guess is they will probably be fairly close.


The other thing I noticed is that I reported an average "per file" size whereas you reported the sum of all the file sizes. If assumptions andreverse math is correct you were getting individual file sizes around 18MB per file and I was getting around 20 MB per filewhich tells me weprobably haddifferent camera setups.


If one of our science based forum members are willing to design a test we can all do, I would be more than willing to participate


Bob

[Richard Lane]

I also received my 32GB 90MB/s SanDisk Extreme Pro CF card.


With the 7D, I just shot 70 raw shots which totaled 1.31GB of data for 20 seconds and the red access light stayed on for an extra 7 seconds after I stopped shooting, for a total of 27 seconds.


I ran the test 3 times with similar results.


1310MB/27sec = 48.5MB/sec.

[HDNitehawk]

@Bob , my first tests I was getting larger file sizes. Once I turned off the Auto ISO I didn't have that problem.


If you were going to compare from one person's 7D to the other, the simplest way to match settings would be to go in to the camera and just restore it to the default settings. That way everyone would start with the same setting.


One problem I see, is if you are doing it without the lens cap, each of you will get different results. I noticed this with the 1D IV, I did a series without the cap and I was outside. A bit later I did another series and got different results, the only difference was the lighting. It was outside and the sun had gotten lower in the sky. When I did tests with cap on the results were consistent from one test to the next.


It would be interesting to see if everyone that bought one of the "on sale" cards, get the same results.


@Brant..I talked to Hoodman earlier, explained what I found on the testing (16MB vs 32MB). They said it is possible the camera takes longer to write to the larger card. They took my phone number, camera type info and told me they were going to check it out themselves. Odd though they said they had not heard this scenario / complaint before.


Even if that is the case it sounds like your card is really slow.

[Richard Lane]

7D with 32GB 90MB/sec SanDisk Extreme Pro CF card:


In a 3 second burst; I shot 22 RAW shots totaling 408MB. The red access light stayed on for 5 seconds after I stopped shooting for a total time of 8 seconds. I ran the test 3 times with similar results.


408MB/8sec= 51MB/sec

[HDNitehawk]

I also received my 32GB 90MB/s card.


With the 7D, I just shot 70 raw shots which totaled 1.31GB of data for 20 seconds and the red access light stayed on for an extra 7 seconds after I stopped shooting, for a total of 27 seconds.


1310MB/27sec = 48.5MB/sec.

Rich


Do you have a smaller card you can compare to, see if there is any difference?

[Richard Lane]

No, but I have a larger card, namely the SanDisk Extreme Pro 64GB 90MB/sec CF card.

[Richard Lane]

I ran the test 3 times with eachand posted the average speeds:





With the 32GB 90MB/sec Card:





3sec burst test= 51MB/sec


20sec test= 48.5MB/sec









With the 64GB 90MB/sec card:


3sec burst test= 47MB/sec


20sec test= 44.5MB/sec





The larger 64GB card was a little slower!
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[Kayaker72]

I also received my 32GB 90MB/s SanDisk Extreme Pro CF card.


With the 7D, I just shot 70 raw shots which totaled 1.31GB of data for 20 seconds and the red access light stayed on for an extra 7 seconds after I stopped shooting, for a total of 27 seconds.


I ran the test 3 times with similar results.


1310MB/27sec = 48.5MB/sec.

Hi Rich,


Good, I am glad to hear it. I just re-ran my tests and the new 32 GB 90 MB/s card is still writing at 17-18 MB/s. I must have received a bad card. I'll be contacting B&amp;H, not so much that my shooting style needs 90 MB/s, but more because if one thing is wrong with the card, what else is wrong with it?


Bob,


I'd be happy to run additional tests. I have been conducting mine with the following conditions:

• EF 100 mm L, AF off, IS off, auto review off, manual mode set to 1/100, f/5.6 and ISO 100, RAW only, High-speed continuous mode
• Shooting at a blank white paper
• Recording the number of shots, file size and write time (red LED) after shooting for 3 seconds (typical time to fill buffer) and 20 seconds.

My file sizes are typically 17.5-17,.8 MB per picture.


That said, I buy Rich's results. It makes sense that the 7D is limited to the ~50 MB/s range and that cards can perform up to that range. I still think I will stick with the 90 MB/s even though it is not needed for the 7D just because it may be of use for something down the line.


Thanks for all your help,


Brant

[neuroanatomist]

I just re-ran my tests and the new 32 GB 90 MB/s card is still writing at 17-18 MB/s. I must have received a bad card. I'll be contacting B&amp;H, not so much that my shooting style needs 90 MB/s, but more because if one thing is wrong with the card, what else is wrong with it?

Brant, I suspect there is nothing wrong with your new card. You just need to update your 7D's firmware. I did notice that the most recent updates for both the 5DII and 7D included, "Improves writing/reading speeds when using UDMA 7-compatible CF cards." Now, I realize that the 90 MB/s cards are rated UDMA 6, but still, it seems reasonable that something stated to affect speeds for faster cards might be the issue.


I've been running older firmware on both my bodies for a while, not seeing a need to update. ButI just ran tests based on your settings, first with the older versions I had been running (1.2.2 on the 7D and 2.0.8 on the 5DII), then after the update (1.2.5 for the 7D, 2.0.9 for the 5DII). I tested 4 cards (all SanDisk, 2 GB 20 MB/s, 8 GB 60 MB/s, 16 GB 60 MB/s, and 32 MB 90 MB/s) on both bodies. But the short version that addresses your issue, Brant, is that with the old firmware, the 32 GB 90 MB/s card performed only slightly faster than the old 2 GB 20 MB/s card, but with the current firmware, performance of the 90 MB/s card on both bodies was slightly better than the 60 MB/s cards (both 8 and 16 GB, which weren't different from each other).


I'll tabulate all the results and post them (probably not until tomorrow, I'm pretty busy for the rest of the night).


Hope that solves a mystery for everyone, and fixes your problem, Brant!


--John

[HDNitehawk]

After reading John's post, I went back to check if I had the current firmware update on the 1D IV. Sure enough I didn't


I rechecked my results. After the firmware update I am getting identical results to those I had previously. So on my end no mystery solved yet.