Sandisk Memory Cards

[neuroanatomist]

Thanks, Rick and Bob. All my CF cards are 60 MB/s. While the $60 price for the 90 MB/s is reasonable, I don

[Kayaker72]

Yep, thanks Rick and Bob.


I have a 30 MB/s Sandisk Extreme III card and a 60 MB/s Sandisk Extreme card. I just did a test and both shot 24 RAW files at the same manual settings before slowing down. But, almost perfectly, the 7D spent ~10 seconds writing the 24 shots to the 60 MB/s card and 21 seconds to write the same number of shots to the 30 MB/s card. The files are approximately 20 MB, so it appears the 60 MB/s card writes at ~48 MB/s and the 30 MB/s card writes at ~23 MB/s.


So, it seems that the benefit is in shooting beyond 24 shots....But as I have never done that prior to this test, I don't think I need a 90 MB/s card. Granted, I may get a 16 GB card and may spend the extra $10 just in case I do someday need the speed.

[Richard Lane]

I have the Sandisk 32GB 60MB/s Extreme and 64GB 90Mb/s Extreme Pro. I use the 60MB/s card in the 7D and the 90MB/s in the MKIV. They seem pretty close to me and I haven

[btaylor]

Man that

[Richard Lane]

I also ordered a 32GB 90MB/s Extreme Pro!


When I added it to the cart the price dropped even further from $112 to $99. Get them while they last!


Remember to use the B&H link from this website to help support the site!


Rich

[Kayaker72]

I also ordered a 32GB 90MB/s Extreme Pro!


When I added it to the cart the price dropped even further from $112 to $99. Get them while they last!

Done..........

Remember to use the B&H link from this website to help support the site!

....and done.....Thanks for the tip on the price reduction. I checked out a couple of other Sandisk cards and it seems like a pretty consistent mark down when you add each card to the cart. Both 16 GB cards dropped by $6, the 32 GB 60 MB/s dropped by $10 ($89 to $79) and the 32 GB 90 MB/s dropped by $13.

[neuroanatomist]

<span>

When I added it to the cart the price dropped even further from $112 to $99. Get them while they last!<span>

<span>

I checked out a couple of other Sandisk cards and it seems like a pretty consistent mark down when you add each card to the cart. Both 16 GB cards dropped by $6, the 32 GB 60 MB/s dropped by $10 ($89 to $79) and the 32 GB 90 MB/s dropped by $13.

Unfortunately, as of this morning those extra discounts seem to be gone at B&amp;H<span>- cart price is the same as browsing price. Glad I ordered last night!

[HDNitehawk]

John &amp; Bob


After reading Bob's post I decided to check to see how much benefitI was getting with a faster card on my 1D IV (sorry I do not have two scandisk to compare but I would think you would get similar results)


This is the test:

1. A 20 second burst
2. camera set to high speed
3. AF off so the camera didn't hunt
4. lens hood on so it was shooting a total black surface
5. full size RAW format
6. 2 tests for each card
7. reformat the card clean each time

First Test a Hoodman 32 GB UDMA 675X which is supposed to do 100mbs


Camera shows a burst limit of 23


Between 3 and 4 seconds the burst stops and the rate slows


At 20 seconds this card both times delivered 63 pictures


Second test a Hoodman 8 GB UDMA 300x which is supposed to do 45mbs


Camera shows a burst limit of 23


Between 3 and 4 seconds the burst stops and rate slows


At 20 seconds this card delivered 61 and 60 pictures





From what I see any limit in performance is minimal only a loss of three pictures. I think the speed of the processors is probably a bigger limiting factor. Someone can tell me if comparing these cards is not a fair comparison of speed, since they are both supposed to be high performance cards.


Even though my testing seems to indicate just a slight difference, just 4 or 5 %, I would stick with the faster card. On a rare occasion the 5% advantage could be the difference. A year and a half ago at Yellowstone armed with my 500mm 1.4x on the 5D II, watching 2 eagles and there baby an Osprey came to close. The Eagles left the roost, they shrieked and the baby dove in to the bushes. One eagle went straight to the Osprey, the other went down a treeline and snuck in behind him. For what seemed like several minutes, which it probably wasn't, the eagles and osprey did an aerial ballet that any fighter pilot would have been proud of. Finally the Osprey bugged out and one of the eagles flew directly over my head not 20 feet from me and gave me the perfect incoming pose. Through this entire fight I watched as my 5D II flashed busy...busy...click...busy...busy.... For me this was an opportunity I may never get again, even though I hear it is pretty common with Eagles and Osprey, getting to take pictures of Eagles where I am from is rare.....I will take the 5% advantage and increase the odds of the picture of a lifetime.


John, the 1D IV has several options for the second card. I use a 32mb card as the second, and it is not a fast card. There are allot of options you can do, but I just set mine as a rollover card in case the first fills up. I have filled the card once and had it go to the back up card one time so far, the only problem with that is I had to reset it to the right card once I downloaded the pictures. I suppose it would be a good option to have if you copied your pictures to both cards, it would give you a little extra security. I heard somewhere that doing that would slow the camera down.

[HDNitehawk]

so it appears the 60 MB/s card writes at ~48 MB/s and the 30 MB/s card writes at ~23 MB/s

Is it possible that around 48mbs is the cameras limit, and going from 60 to 90 may just be wasted speed. I guess a question would be is how fast can the camera write if it has all the speed possible in the card.


48mbs could explain why I had 3 less pictures with a 45mbs card. Maybe if I had a 60mbs card I would have seen no difference.

[Kayaker72]

so it appears the 60 MB/s card writes at ~48 MB/s and the 30 MB/s card writes at ~23 MB/s

Is it possible that around 48mbs is the cameras limit, and going from 60 to 90 may just be wasted speed. I guess a question would be is how fast can the camera write if it has all the speed possible in the card.


48mbs could explain why I had 3 less pictures with a 45mbs card. Maybe if I had a 60mbs card I would have seen no difference.

Rick,


I'll let one of those that know more answer for sure, but the numbers work out perfectly assuming your files were ~20 MB each. (the 3 pictures would be 60 MB or 3 MB for each of the 20 seconds you shot).


One of the things I found interesting about my test was that each slowed down at 24 shots in ~3 secs (no noticable difference between the 30 MB/s and 60 MB/s cards), which, indicates to me that files are not being written to the card during those 3 seconds of shooting. If they had been, I would expect at least at least a slight difference (I also ran my tests twice, each time coming up with the same # of shots).


Anyway, it definitely seems that something besides the card write speed is limiting shooting speed.


Brant