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rlatjsrud · 03-10-2012, 11:00 PM

I have sandisk 95mb/s 8gb... but problem is K-5 does not use all 95mb/s. It's just use only half of it. I hope that Pentax could make 95mb/s over for body.

Anvh · 03-11-2012, 04:09 AM

Originally posted by WerTicus

The next pentax camera will support UHS1 no doubt so i am only adding those to my collection from now on. But there is no point currently.

The next Pentax camera???
You're behind the facts you know, the K-01 support the USH-1 standard so the camera is already here.

And there is a point now to get faster cards, do you know how long it can take to import 32GB

Anvh · 03-11-2012, 04:13 AM

Originally posted by RonHendriks1966

There is some pieking in writespeed, but overal we are stuck with a lower average writespeed that slows down the whole process and ending up with a full buffer and a slow framerate after full buffer.

That's the question, does it write to the SD card all the time when you're taking photos or not?
Also is it the SD that slows things down or the processor?

Those are all things you can't test or find out.

What you've calculated now is that the camera output is around 18MB/s but that's something different then saying that the SD card bus in the K5 has that speed.
Therefore if you want to be sure that the SD card isn't the limiting factor you should get a faster card then that.

RonHendriks1966 · 03-11-2012, 12:03 PM

Originally posted by Anvh

What you've calculated now is that the camera output is around 18MB/s but that's something different then saying that the SD card bus in the K5 has that speed.
Therefore if you want to be sure that the SD card isn't the limiting factor you should get a faster card then that.

This test was with the SanDisk Pro 45MB/s UHS-I card so it isn't the card that limiteds the writespeed. But it could also be just the infrastructure inside the camera that is slowing down.

My guess is that the cardreader in the camera is the limiting thing. With my laptop the cardreader is also topping out at about 18 MB/s while when I put my USB 3.0 cardreader in USB 2.0 port (no 3.0 on the laptop) it tops at 22,2 MB/s second whil on my PC with USB 3.0 port it goes up to 42 MB/s readspead.

Anvh · 03-11-2012, 01:06 PM

And your guess is based on what?

Btw does anyone know how the data gets handled?

This the pad it takes as far as i know

sensor > RAM > image-processor > RAM > but where does it go from there, which component is in charge to transfer the file from the RAM to the SD card is it the image-processor?

**monochrome** · 03-11-2012, 01:28 PM

Originally posted by Anvh

And your guess is based on what?

Btw does anyone know how the data gets handled?

This the pad it takes as far as i know

sensor > RAM > image-processor > RAM > but where does it go from there, which component is in charge to transfer the file from the RAM to the SD card is it the image-processor?

At the end there's a bus to the card. That seems a likely bottleneck.

Gimbal · 03-11-2012, 02:29 PM

I don't know but I assume the data to be written is send to a buffer and a thread/task/interrupt is pumping out the data as fast as the hardware allows it.

Anvh · 03-11-2012, 02:35 PM

Originally posted by monochrome

At the end there's a bus to the card. That seems a likely bottleneck.

But the bus isn't a processor so it can't take data off the RAM and write it to the SD card.

From what i've seen from the image processor it also is responsible to write to the SD card

03-11-2012, 04:09 AM	#32
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by WerTicus The next pentax camera will support UHS1 no doubt so i am only adding those to my collection from now on. But there is no point currently. The next Pentax camera??? You're behind the facts you know, the K-01 support the USH-1 standard so the camera is already here. And there is a point now to get faster cards, do you know how long it can take to import 32GB Last edited by Anvh; 03-11-2012 at 04:16 AM.

03-11-2012, 02:35 PM	#38
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by monochrome At the end there's a bus to the card. That seems a likely bottleneck. But the bus isn't a processor so it can't take data off the RAM and write it to the SD card. From what i've seen from the image processor it also is responsible to write to the SD card Last edited by Anvh; 03-11-2012 at 02:42 PM.

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03-10-2012, 11:00 PM	#31
rlatjsrud Guest	I have sandisk 95mb/s 8gb... but problem is K-5 does not use all 95mb/s. It's just use only half of it. I hope that Pentax could make 95mb/s over for body.

03-11-2012, 04:13 AM	#33
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by RonHendriks1966 There is some pieking in writespeed, but overal we are stuck with a lower average writespeed that slows down the whole process and ending up with a full buffer and a slow framerate after full buffer. That's the question, does it write to the SD card all the time when you're taking photos or not? Also is it the SD that slows things down or the processor? Those are all things you can't test or find out. What you've calculated now is that the camera output is around 18MB/s but that's something different then saying that the SD card bus in the K5 has that speed. Therefore if you want to be sure that the SD card isn't the limiting factor you should get a faster card then that.

03-11-2012, 12:03 PM	#34
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	Originally posted by Anvh What you've calculated now is that the camera output is around 18MB/s but that's something different then saying that the SD card bus in the K5 has that speed. Therefore if you want to be sure that the SD card isn't the limiting factor you should get a faster card then that. This test was with the SanDisk Pro 45MB/s UHS-I card so it isn't the card that limiteds the writespeed. But it could also be just the infrastructure inside the camera that is slowing down. My guess is that the cardreader in the camera is the limiting thing. With my laptop the cardreader is also topping out at about 18 MB/s while when I put my USB 3.0 cardreader in USB 2.0 port (no 3.0 on the laptop) it tops at 22,2 MB/s second whil on my PC with USB 3.0 port it goes up to 42 MB/s readspead.

03-11-2012, 01:06 PM	#35
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	And your guess is based on what? Btw does anyone know how the data gets handled? This the pad it takes as far as i know sensor > RAM > image-processor > RAM > but where does it go from there, which component is in charge to transfer the file from the RAM to the SD card is it the image-processor?

03-11-2012, 01:28 PM	#36
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	Originally posted by Anvh And your guess is based on what? Btw does anyone know how the data gets handled? This the pad it takes as far as i know sensor > RAM > image-processor > RAM > but where does it go from there, which component is in charge to transfer the file from the RAM to the SD card is it the image-processor? At the end there's a bus to the card. That seems a likely bottleneck.

03-11-2012, 02:29 PM	#37
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	I don't know but I assume the data to be written is send to a buffer and a thread/task/interrupt is pumping out the data as fast as the hardware allows it.

maximum useful SD card speed

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