SD memory card question

I've just received a new SD card from an Amazon supplier. The listing was
for a 4GB class 10 30mb/s card - a class 6 30mb/s card has arrived. They are
both 30mb/s, what's the class 6 and class 10 telling me? I can't even find a
class 6 30mb/s on the Sandisk website.

John

I've just received a new SD card from an Amazon supplier. The listing
was for a 4GB class 10 30mb/s card - a class 6 30mb/s card has arrived.
They are both 30mb/s, what's the class 6 and class 10 telling me? I
can't even find a class 6 30mb/s on the Sandisk website.

John

Does this page help?

http://www.sdcard.org/developers/tech/speed_class/

Class 10 appears to have a "High Speed Bus I/F" (but it doesn't say what
speed interface "High Speed" is), and class 6 a "Normal Speed". Seems to
me that class 6 would not be as good for some applications, but probably
quite adequate for still camera use.

Cheers,
David

"David J Taylor" wrote in message
...
I've just received a new SD card from an Amazon supplier. The listing was
for a 4GB class 10 30mb/s card - a class 6 30mb/s card has arrived. They
are both 30mb/s, what's the class 6 and class 10 telling me? I can't even
find a class 6 30mb/s on the Sandisk website.

John

Does this page help?

http://www.sdcard.org/developers/tech/speed_class/

Class 10 appears to have a "High Speed Bus I/F" (but it doesn't say what
speed interface "High Speed" is), and class 6 a "Normal Speed". Seems to
me that class 6 would not be as good for some applications, but probably
quite adequate for still camera use.

Cheers,
David

Thanks for that. I'm still puzzled by the lack of this particular card on
the Sandisk website. Does class6 do 30mb/s? Is it old stock and hence no
longer listed with Sandisk? Is the card a fake? The supplier was through
Amazon so they should be ok. I will contact Sandisk and see if they ever
produced such a card.

John

Thanks for that. I'm still puzzled by the lack of this particular card
on the Sandisk website. Does class6 do 30mb/s? Is it old stock and hence
no longer listed with Sandisk? Is the card a fake? The supplier was
through Amazon so they should be ok. I will contact Sandisk and see if
they ever produced such a card.

John

Yes, worth checking - but these cards change so rapidly I /think/ you will
be OK. A test program I've used is:

h2testw.exe (free)
http://www.heise.de/software/download/h2testw/50539

which will find cards which have less memory than advertised, and:

HD Tune 2.55 (free)
http://www.hdtune.com/download.html

for additional speed tests.

Cheers,
David

"David J Taylor" wrote in message
...
Thanks for that. I'm still puzzled by the lack of this particular card on
the Sandisk website. Does class6 do 30mb/s? Is it old stock and hence no
longer listed with Sandisk? Is the card a fake? The supplier was through
Amazon so they should be ok. I will contact Sandisk and see if they ever
produced such a card.

John

Yes, worth checking - but these cards change so rapidly I /think/ you will
be OK. A test program I've used is:

h2testw.exe (free)
http://www.heise.de/software/download/h2testw/50539

which will find cards which have less memory than advertised, and:

HD Tune 2.55 (free)
http://www.hdtune.com/download.html

for additional speed tests.


Thanks again. Things have moved on. I sent a question to Sandisk, the form I
completed did list the card I've received. I read around the class issue and
it appears that the class of card is most important when shooting movies -
not something I do much of. I then read the instruction book for my new
camera (1D mk IV) - the card class needs to be 6 or higher. So I cut open
the plastic packaging (making the card non returnable), set the camera to
highest resolution and fastest frame rate movie setting. I then shot an
exciting movie of cars going past my house - the buffering indicator did not
appear in the viewfinder. The card is fast enough to read data from the
camera at the most demanding movie setting without the camera using it's
buffer. It rankles slightly that I've not got the advertised card but as
it's living in slot 2 as an overflow card it will no doubt do it's job.

John

Thanks again. Things have moved on. I sent a question to Sandisk, the
form I completed did list the card I've received.

A relief!

I read around the class issue and it appears that the class of card is
most important when shooting movies - not something I do much of. I then
read the instruction book for my new camera (1D mk IV) - the card class
needs to be 6 or higher. So I cut open the plastic packaging (making the
card non returnable),

Certainly not - if the card was faulty of did not meet the performance
expectations, you could still return. How else does one test?

set the camera to highest resolution and fastest frame rate movie
setting. I then shot an exciting movie of cars going past my house - the
buffering indicator did not appear in the viewfinder. The card is fast
enough to read data from the camera at the most demanding movie setting
without the camera using it's buffer. It rankles slightly that I've not
got the advertised card but as it's living in slot 2 as an overflow card
it will no doubt do it's job.

John

Agreed. And if the camera needs Class 6, you are OK. Might be
interesting to check prices and see just how much, if any, you were over
charged. I usually get my cards from 7-day shop - I wonder how they
compare with Amazon?

Cheers,
David

On Wed, 18 Aug 2010 10:53:24 +0100, "David J Taylor"
wrote:

Thanks for that. I'm still puzzled by the lack of this particular card
on the Sandisk website. Does class6 do 30mb/s? Is it old stock and hence
no longer listed with Sandisk? Is the card a fake? The supplier was
through Amazon so they should be ok. I will contact Sandisk and see if
they ever produced such a card.

John

Yes, worth checking - but these cards change so rapidly I /think/ you will
be OK. A test program I've used is:

h2testw.exe (free)
http://www.heise.de/software/download/h2testw/50539

which will find cards which have less memory than advertised, and:

HD Tune 2.55 (free)
http://www.hdtune.com/download.html

for additional speed tests.

Cheers,
David

And many don't realize that the card-reader itself is often the bottleneck
when performing these tests.

On 10-08-18 4:56 , eatmorepies wrote:
I've just received a new SD card from an Amazon supplier. The listing was
for a 4GB class 10 30mb/s card - a class 6 30mb/s card has arrived. They are
both 30mb/s, what's the class 6 and class 10 telling me? I can't even find a
class 6 30mb/s on the Sandisk website.

well, first off, a millibit per second is really slow. (MB=megabye,
mb=millibit).

See the wikipedia article for clarification on classes (which don't
correspond to your values above).

http://en.wikipedia.org/wiki/Secure_...d_Class_Rating

--
gmail originated posts are filtered due to spam.

"Alan Browne" wrote in message
...
On 10-08-18 4:56 , eatmorepies wrote:
I've just received a new SD card from an Amazon supplier. The listing was
for a 4GB class 10 30mb/s card - a class 6 30mb/s card has arrived. They
are
both 30mb/s, what's the class 6 and class 10 telling me? I can't even
find a
class 6 30mb/s on the Sandisk website.

well, first off, a millibit per second is really slow. (MB=megabye,
mb=millibit).

Nope, mb is megabit

On 10-10-01 18:36 , DocGlock wrote:
"Alan wrote in message
...
On 10-08-18 4:56 , eatmorepies wrote:
I've just received a new SD card from an Amazon supplier. The listing was
for a 4GB class 10 30mb/s card - a class 6 30mb/s card has arrived. They
are
both 30mb/s, what's the class 6 and class 10 telling me? I can't even
find a
class 6 30mb/s on the Sandisk website.

well, first off, a millibit per second is really slow. (MB=megabye,
mb=millibit).

Nope, mb is megabit

That would be Mb, but thanks for playing.

--
gmail originated posts are filtered due to spam.