SDHC

[Cope This 719]

A Happy and a Holy Christmas and a great New Year to everyone.

I am contemplating getting an additional storage card for my Canon HFS 21, it takes SD cards. What is the difference between Grade 4,6, and 10. Is there a difference between brands.

Any help most appreciated.
John

[Peru]

Class 10 is the fastest. That is what you want to use.

See here:
viewtopic.php?f=1&t=11631

[Dave McElderry]

It's a little more pricey (not terribly so), but I'm a fan of SanDisk. Never had a problem.

[Cope This 719]

Thanks very much for your advice. I am also a fan of San Disk.

Regards John

[Cope This 719]

Can anyone tell me the difference between Sandisk 32 GB ultra and Sandisk 32GB Extreme both rated at 10. I will be using one of these cards in a Canon hfs 21.

Regards John

[Bob]

Names like Ultra, Extreme, and Extreme Pro are marketing categories. In general, Extreme is faster than Ultra, and Extreme Pro is the fastest. However, there is some overlap especially when you consider the mix of old and new models available in stores. There is also the issue of UHS-1 support. To compare two cards, you really need to know the specs of the specific models.

There are several ways to measure the performance of an SDHC card. One is Class rating which defines the minimum sustained write speed in megabytes per second that can be written to the card. Another is Speed rating which measures the maximum read/write speed.

Speed rating is import where the maximum speed of the card is important. Such as when using a DSLR shooting high resolution or raw files where you might not be able to shoot another photo while while waiting for the image buffer to be written to the card. This is expecially noticable when shooting in multi-shot burst mode. SanDisk puts the Speed rating on the card.

Class rating is import where you need to guarantee that a minimum sustained rate of data can be recorded under any circumstances -- video, for example. If the card cannot keep up with the sustained rate the video is recording, you will drop frames and lose data. Your camera manual should tell you the minimum Class rating to required for your camera. You can use higher Class ratings without problems. The fastest standard Class Rating is Class 10. The SanDisk Ultra should be all you need for video.

There is another Class Rating system, the UHS rating. Currently there is only one class: UHS-1. UHS cards achieve a higher performance rating by increasing the clock speed that controls the writing of data to the card. To gain the increased speed, the device you use it in must have a controller that supports that feature. UHS cards will revert back to the standard interface if you use them in a device that doesn't support UHS. These cards are generally marked as UHS-1 and Class 10. They will perform as Class 10 in most consumer camcorders.

If you get a card reader that supports UHS-1, you can use it to transfer data from the card to your computer instead of going through your camcorder and possibly get a higher transfer rate when using a UHS-1 card.

[Peru]

http://www.ehow.com/about_6122859_diffe ... cards.html

and

http://techtips.salon.com/difference-be ... 25271.html


The manual doesn't say that it supports SDXC (page 36}:
http://gdlp01.c-wss.com/gds/6/030000323 ... nim-en.pdf

[Bob]

Those pages are a little dated. Extreme Pro, Extreme, and Ultra all come in SDHC and SDXC. Most are now UHS-1 as well. Ultra still has non-UHS-1 cards. Here's the current lineup: http://www.sandisk.com/products/memory-cards/sd/. You can still find non-UHS-1 Extreme cards in some stores.