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20GB per sec CF cards- any point?

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Raymo1

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Ultra III, Lexar x133 etc, all boast 20GB/sec read and write, but todays cameras don't seem to be taking advantage of these higher speed cards.

Can we expect Canon and others to release new cameras that will write at 20GB sec ?

Or is thers a good technical reason why we won't be seeing this in the near future ?

--
Ray
 
Since the camera itself can't take pictures faster than a few frames per second (8.5 fps is the current fastest with the 1Dmk2) and memory is dirt cheap, the more practical solution seems to be to add a large buffer to hold a burst of shots and write to the CF card with a slower bus interface. The write speed to internal memory will always be faster than to an external card, so buffering will always be a part of the write chain.

However, the typical camera CF write speeds we see now may have been dictated more by the slower write speed limitations of earlier CF cards rather than electronic design tradeoffs within the camera itself. So its quite possible we could start seeing faster CF interfaces in the near future. But since the fps number is limited more by camera mechanics and probably won't increase much in models in the price range of the 20D/30D, the overall impact of faster CF writing on the photographic process is probably minimal.
Raymo1 said:
Ultra III, Lexar x133 etc, all boast 20GB/sec read and write, but
todays cameras don't seem to be taking advantage of these higher
speed cards.

Can we expect Canon and others to release new cameras that will
write at 20GB sec ?

Or is thers a good technical reason why we won't be seeing this in
the near future ?

--
Ray
Click to expand...
 
Raymo1 said:
Ultra III, Lexar x133 etc, all boast 20GB/sec read and write, but
todays cameras don't seem to be taking advantage of these higher
speed cards.

Can we expect Canon and others to release new cameras that will
write at 20GB sec ?

Or is thers a good technical reason why we won't be seeing this in
the near future ?

--
Ray
Click to expand...
 
There is a big difference between 20GB per second and the actual advertised rate of 20MB per second.

New Lexar 133X cards * 150 Kb per 1X = 19950 kb or 19.95Mb
 
There certainly isn't a HardDrive built today that can transfer 20GB a second, nor does USB 2.0 transfer that fast. Heck, Even FireWire 800 isn't THAT fast. Not sure what the transfer to internal RAM is, but I'm betting it's not too far above 20GB a second, if it is that high.

Assuming it's a realistic speed, and you had the HD and the cable to go that fast, the difference between transfering a 10GB card at 10GB/s and 20GB/s is exactly 0.5 seconds. Not that big a deal me thinks...

Someone explain to me how I'm wrong?
 
I should have figured the numbers were wrong. Guess I should check those things before making my replies ;-)

But I wouldn't put it past tech companies to post a theoretical in lab transfer rate as a real world rate.

300gb HD anyone? ;-)

Tyler
 
Assuming it's 20MB/sec, there is no telling the upcoming new Canon 1D bodies that are not capable of doing that or close to it.

When the 10MB/sec Ultra II came out there were plenty of cameras could only achieve 1/10 of the speed. But if you look at today's cameras, many can achieve or surpass that speed.
--
Nelson Chen
http://pbase.com/nelsonc
100% RAW shooter with Capture One Pro

 
I think it is MB/s, not GB/s.

I'm not sure what the limits are with SOTA everything, but I know when I got a 20D recently, this triggered me to get some 2 gig cards to supplement my old Transcend 45x 1 gig cards, I noticed that the new cards (SanDisk Extreme II and RiData 150X downloaded about twice as fast as what I was getting with my 45X cards. ( 12.5 MB/s instead 6.5 MB/s)

I know that my computer is several years old and my Sandisk card reader is at least a year old. I use non-RAID PATA drives. I figured that if my creaky old computer could download at 12.5 MB/s, that all new SOTA everything has a chance of utilizing the 20 MB/s that the new cards are advertised as delivering.

Wayne
Earendil_Star said:
There certainly isn't a HardDrive built today that can transfer
20GB a second, nor does USB 2.0 transfer that fast. Heck, Even
FireWire 800 isn't THAT fast. Not sure what the transfer to
internal RAM is, but I'm betting it's not too far above 20GB a
second, if it is that high.

Assuming it's a realistic speed, and you had the HD and the cable
to go that fast, the difference between transfering a 10GB card at
10GB/s and 20GB/s is exactly 0.5 seconds. Not that big a deal me
thinks...
Click to expand...
 
My new Transcend 120X CF card can achieve near 20MB/sec when using the Sandisk ImageMate CF card reader SDDR-92 to download .CR2 files.
--
Nelson Chen
http://pbase.com/nelsonc
100% RAW shooter with Capture One Pro

 
Yes, sorry all, I ment to say 20Mb per second, not GB.

And yes, read speed is important too, so the faster cards will shine there.

I was considering which 4gb card to purchase, the Ultra II or Ultra III.

I guess it is probable that Canon will come out with a camera capable of using the faster write speeds.
 
for most parts, it cuts down on the download time,

on a 4gb microdrive was 15min plus,
on a 4GB SD it's 5min plus, laptop
I use CF SD adapter,
for camera use, it makes very little difference,

cheers, Robert
--
http://www.RobsPhoto.com
 
The only time you'll notice a difference is when you download images to a computer using a card reader, particularly a card reader using a USB 2.0 or Firewire interface.
Richard
 
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