Fast and slow SD Cards

I was going to get a spare SD Card for a recorder and the tech
support guy said to get one which was under 2GB and not high speed.

I can understand the recorder may not support SDHC and won't
recognise a 2GB+ card.

But what is that about not using a fast SD Card. Surely my recorder
ought to work whatever the speed of the SD memory card?

Was he talking crap?

dave wrote:
I was going to get a spare SD Card for a recorder and the tech
support guy said to get one which was under 2GB and not high speed.

I can understand the recorder may not support SDHC and won't
recognise a 2GB+ card.

But what is that about not using a fast SD Card. Surely my recorder
ought to work whatever the speed of the SD memory card?

Was he talking crap?

May he's just saying that investing in really fast cards isn't going to
help much. A recorder (sound? camcorder?) has a fixed write rate so when
recording you don't need a card much faster than that.

Having a fast card can however be a good thing when transferring the
files to a computer.

--
Bertrand

"dave" wrote in message
news
I was going to get a spare SD Card for a recorder and the tech
support guy said to get one which was under 2GB and not high speed.

I can understand the recorder may not support SDHC and won't
recognise a 2GB+ card.

But what is that about not using a fast SD Card. Surely my recorder
ought to work whatever the speed of the SD memory card?

Was he talking crap?

The speed rating of the card is the fastest that it can manage, not the
speed that it *must* run at. A fast card will transfer slowly when
necessary! It will cost more though, so if you don't need fast transfer
speeds, then you can save money by buying a slower one.

europe.news.astraweb.com wrote:
"dave" wrote in message
news
I was going to get a spare SD Card for a recorder and the tech
support guy said to get one which was under 2GB and not high speed.

I can understand the recorder may not support SDHC and won't
recognise a 2GB+ card.

But what is that about not using a fast SD Card. Surely my recorder
ought to work whatever the speed of the SD memory card?

Was he talking crap?

The speed rating of the card is the fastest that it can manage, not the
speed that it *must* run at. A fast card will transfer slowly when
necessary! It will cost more though, so if you don't need fast transfer
speeds, then you can save money by buying a slower one.


I don't have a camera that uses SDHC, but I have an mp3 player that
does. I have some very slow (read cheap) 16gb SDHC cards that are that
take ages to load data onto, but once the player they are just as good
as the fastest.
Allen

I's ONLY SDHC cards that are 4x and 6x.

The SDHC technology was specifically developed to allow higher speed
read/writed. To handle SDHC card's higher speed, the device must have read
and write buffers to stop over-runs (which loses data). So the tech support
guy wasn't talking crap.

dave wrote:
I was going to get a spare SD Card for a recorder and the tech
support guy said to get one which was under 2GB and not high speed.

Maybe he meant, "Don't get a High Capacity card".
That would, of course be a SDHC, which may not in fact, be compatible
with your recorder.
As far as speed is concerned, high speed cards are really nice for
downloading images to your computer.
Most manufacturers don't advertise the card's speed but some do.
My SD cards that are rated at 150X do a very good job.
I have recently seen a SDHC card rated as 300X, but I have not used it.
Bob Williams

With respect Bob, virtually all SDHC card maufacturers do advertise the
card's speed - on the card itself. You'll see a number (usually within a
circle) which indicates that card's speed and is called "Class".
Respectively,

Class 2 is rated at 2.0 MBytes per second.
Class 4 is rated at 4.0 or 4.8 MBytes per second.
Class 6 is rated at 6.0 MBytes per second.
Class 10 is rated at 10.0 MBytes per second.
Class 15 is rated at 15.0 MBytes per second.
Class 20 rated at 20.0 MBytes per second.
Class 22 is rated at 22.5 MBytes per second.
Class 30 is rated at 30.0 MBytes per second.
Class 40 is rated at 40.0 MBytes per second.
Class 45 is rated at 45.0 MBytes per second.

Regards...

wrote in message
...
With respect Bob, virtually all SDHC card maufacturers do advertise the
card's speed - on the card itself. You'll see a number (usually within a
circle) which indicates that card's speed and is called "Class".
Respectively,

Class 4 is rated at 4.0 or 4.8 MBytes per second.
Class 6 is rated at 6.0 MBytes per second.
[]

Regards...

Doesn't seem to apply to the SDHC cards I have:

SanDisk - labelled class 4, and 15MB/s

DaneElec- labelled class 6, and 133X (19.95MB/s)

David

On Thu, 15 Oct 2009 16:18:05 GMT,
wrote:

With respect Bob, virtually all SDHC card maufacturers do advertise the
card's speed - on the card itself. You'll see a number (usually within a
circle) which indicates that card's speed and is called "Class".
Respectively,

Class 2 is rated at 2.0 MBytes per second.
Class 4 is rated at 4.0 or 4.8 MBytes per second.
Class 6 is rated at 6.0 MBytes per second.
Class 10 is rated at 10.0 MBytes per second.
Class 15 is rated at 15.0 MBytes per second.
Class 20 rated at 20.0 MBytes per second.
Class 22 is rated at 22.5 MBytes per second.
Class 30 is rated at 30.0 MBytes per second.
Class 40 is rated at 40.0 MBytes per second.
Class 45 is rated at 45.0 MBytes per second.

Regards...


Bob was referring to fast SD, rather than SDHC. To clarify
SD is not class rated it is (nnn)X rated, but many
manufacturers were buying surplus low performance chips and
didn't want to be obligated to provide any particular
minimum performance level so they didn't specify the speed.

However now that flash is so inexpensive per GB, I would not
recommend buying any SD card that isn't at least rated, for
100X or higher rate.