I have recently upgraded from a D7K to the D800 and have 4 Lexar Professional 32GB Class 10 (133x) cards laying around. Not exactly the fastest things on the planet with the D800. I am about to pull the trigger on a 2 pack of Lexar 32GB 1000x CF cards and was curious about dual card usage.

On my D7K I always had it set to backup and wanted to do the same with my D800. My question is:
Does the fact that the SD card is considerably slower than CF card mean that I will only see the benefit of my new CF in reading from the card but writing will be equal to the slowest card when Secondary Slot is set to Backup? Or does the camera clear the buffer after it writes to the CF and then it's a secondary write from the CF to the SD card, or something else.

Just wanted to make sure I didn't have to upgrade my SD cards also.

Nikon D800 | 24-70mm f/2.8G | 70-200mm f/2.8G VR II

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My understanding is that the camera writes to the two card slots serially from the buffer. Therefore, a slow card in either slot will slow down the entire process.

I have a Sandisk Extreme Pro SD card and a Lexar 1000X CF. Run the fastest cards if you have need for rapid continuous shooting.

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So, if that's true, 2 things:
1. Buying a 1000x is pointless if I always shoot backup
2. I have to upgrade my SD cards also

If so, the decision to go SD/CF was silly and should have been 2 CF.

Nikon D800 | 24-70mm f/2.8G | 70-200mm f/2.8G VR II

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>So, if that's true, 2 things:
>1. Buying a 1000x is pointless if I always shoot backup

Hardly. But probably true if you didn't plan on doing media upgrades when buying a new camera.

>2. I have to upgrade my SD cards also

As per usual when making a significant jump in camera.

>If so, the decision to go SD/CF was silly and should have been
>2 CF.

Your opinion. Personally, I love the fact that the D800 has slots for both kinds of media. it means that I can pick up emergency cards in practically any drugstore or supermarket anywhere in the country. Not always possible with CF. It means that I can hand off my FAR less expensive SD cards to the people paying me to shoot if so required. it means that I can pull the SD card out of the camera and put it into my ipad reader or directly into my laptop without an external card reader and wire.

Additionally, since the D800 shoots slower than the D7000, I find them quite similar in all practical use when used with reasonable cards. I shoot Sandisk Extremes for both CF and SD. Seems to work well for me as a sports shooter primarily.

D600 has two SD slots. D3s/D4 have 2 CF slots. Pick your poison.

------
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>Your opinion. Personally, I love the fact that the D800 has
>slots for both kinds of media...

All valid points, but since my post is all about me, I'll go with wish it had 2 x CF slots That said, I grabbed a 2 pack of 32GB Lexar Professional UHS-I 600x cards. Thanks for the info/input.

Nikon D800 | 24-70mm f/2.8G | 70-200mm f/2.8G VR II

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>>Your opinion. Personally, I love the fact that the D800
>has
>>slots for both kinds of media...
>
>All valid points, but since my post is all about me, I'll go
>with wish it had 2 x CF slots That said, I grabbed a 2
>pack of 32GB Lexar Professional UHS-I 600x cards. Thanks for
>the info/input.

LOL! Ok that was funny.

------
Webpage: http://www.ptfphoto.com

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>My understanding is that the camera writes to the two card
>slots serially from the buffer. Therefore, a slow card in
>either slot will slow down the entire process.
>
>I have a Sandisk Extreme Pro SD card and a Lexar 1000X CF.
>Run the fastest cards if you have need for rapid continuous
>shooting.

I second this. I also have a Sandisk Extreme Pro SD and have been very pleased. There is an ENORMOUS difference, even vs. the 30 MB/s Sandisk cards

I would suggest skipping new CF cards. CF is way more expensive than SD, and so much more prone to failure. Having bent pins in a camera before, I'm never going back there.

I only am using SD (the SanDisk Extreme Pro) work very well, haven't noticed the significant buffer lags that I had with slower SD cards. At this point I am only using the CF slot as a backup. When I need to take images off the CF card, I do an in camera copy to SD.

Personally, I'm glad they used one of each - it means I have a permanent repository for one of my CF cards.

I recently bought both the :

Lexar Professional 1000x 64 GB UDMA 7 CF

and

SanDisk Extreme Pro 95MB/S 64 GB SD

I also have a several UDMA 6 CF and 133x SD cards to use as benchmarks.

First the good news: Both the Lexar 1000x and SandDisk 95MB/S cards improve D800 performance.

Then the bad news: improvements in speed vary widely depending on slot configuration.

Almost any card SD or CF, 133x or faster can keep up with JPEG. I routinely get 99+ plus shots without interruption when using JPEG

When shooting RAW, the story is not as good. The D800 has a buffer of about 13 slots regardless of card used. I can use a 133x SD card and get 13 uninterrupted shots. I can use a 1000x UDMA 7 card and still get only 13 uninterrupted shots. The difference between cards becomes apparent only after about 13 shots are taken and the D800 buffer fills up. Different cards clear the buffer over radically different time intervals.

The fastest D800 RAW configuration:
Lexar Professional 1000x 64 GB UDMA 7 CF by itself

Performance: The D800 takes 13 uninterrupted shots and then maintains about 1 fps as the camera buffer gets dumped to the CF card and refills. When you let go of the shutter, the card write light goes off in about 10 seconds.

Comment: UDMA 7 by itself is fast. Inserting any SD card basically slows D800 to SD transfer rates. UDMA 6 CF cards are almost as fast (I have a DELKIN 700x CF). If you have one, you really don't need to upgrade. They maintain about 0.9 fps once the camera buffer is full.

The second fastest D800 RAW configuration:
SanDisk Extreme Pro 95MB/S 64 GB SD by itself
OR
Lexar Professional 1000x 64 GB UDMA 7 CF recording RAW and the SanDisk Extreme Pro 95MB/S 64 GB SD recording JPEG

Performance: The D800 takes 13 uninterrupted shots and then maintains about 1 frame every 2 seconds (0.5 fps) as the camera buffer gets dumped and then refills. When you let go of the shutter, the card write light goes off in about 20 seconds (a little slower when 2 cards are used).

Comment: The SD is the bottleneck. Even with a fast CF card, the D800 slows to SD transfer rates - bbout the same as using just an SD by itself.

The slowest D800 RAW configuration:
Any 133x SD or 133x CF card (one card configuration is slow; 2 cards are even slower)

Performance: The D800 takes 13 uninterrupted shots and then maintains about 1 frame every 10 seconds (0.1 fps or slower). When you let go of the shutter, the card write light can take several minutes to go off.

Comment: Slow cards are serious RAW bottleneck. Once the D800 buffer is full, the camera is pretty much unusable.



I hope this helps.

--

Craig

I recently purchased a D800, and the first thing was that when installing the CF card, I supposedily bent the pins, so off for a $300 repair before the first click. I am looking to installing delkin 32gb cf 1000x UDMA 7 card. I welcome any advise, Iam a newbee.

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The performance numbers I provided above give a pretty clear picture of how the D800 operates. For some reason, many reviewers just describe data rates and write times. I am not sure that gives a clear picture of D800 memory card issues.

No matter which card you use, the D800 can take about 13 RAW shots before slowing down due to a full image buffer. The rate at which the camera recovers from a full buffer is governed by the slowest card in the camera. Writing RAW to one card and JPEG to another is generally the faster dual slot solution, but once again, the slowest card - usually the SD card - is the biggest limiting factor.

Some conclusions:

1. Shooting sports RAW with a D800 is problematic. You have only a few seconds of continuous shooting before your 13 shot buffer fills. In fact, shooting anything faster than 1 fps eventually fills the buffer - even with a 1000x CF card! Similarly, you can't really shoot much faster that 0.5 fps with any available SD card.

Shooting JPEG is really the only viable option for sports. Nothing new here. I have been forced to shoot sports JPEGs since 2006 using a D200. Unfortunately, the situation is mildly worse with the D800 since its buffer clears slower than any other Nikon DSLR I have used.

2. The CF card speed benefit is generally nullified when you add even the fastest SD card. Even writing just JPEGS to the SD card, significantly reduces performance. Given this fact, Nikon may have done better with dual SD slots. It would be cheaper, more convenient and offer about the same real-world, dual card performance.

--

Craig

Craig's description mirrors my experience. I always shoot with a CF+SD in backup mode ever since I had a failure with the CF card.

I have a 1000x Lexar, for the time when I think I need long bursts, but there's something to think about. Bursts are about length of shooting time, NOT about how many shots. So someone thinking about "wow, a D4 can get 75 shots and this can only get 17". But if you think about that as 7 seconds vs. 4 seconds it doesn't sound so different.

I find the D800 pretty slow in frame rate, but the buffer is mostly adequate BECAUSE it shoots slow. The difference in "time to green light off" is dramatically longer with slow cards, but the practical difference doesn't matter to me -- the buffer itself is big enough.

Anyway... My experience so far is I need BIG cards, not so much fast cards. I'll go out to shoot 100 images, and something interesting happens, and suddenly 100 becomes 500 or 800 and the card is full. Yet I almost never hit the buffer limit.

When I first got this I worried a lot about card speeds, testing sitting at my computer and shooting long bursts of my wall. But when I got out and actually USED the camera, I found the super fast cards mostly irrelevant. Your mileage may vary, just suggesting.

Linwood

PS. The Lexar 1000x failed on me, it is the only CF card ever to fail in any camera for me. One data point does not a trend make, but I keep it in my bag for when I really need long bursts, and I worry less.

PPS. there is another practical difference -- if you chimp a lot, you often have to wait for "green light off" to start viewing the last few photos. This can be a reason for a faster card even if you don't shoot bursts. I just put up with it, and try not to chimp so much anyway.

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>...if you chimp a lot, you often have to wait for "green light off" to
>start viewing the last few photos...

I've been busted. That's it, I'm changing my name to SirChimpsAlot

Nikon D800 | 24-70mm f/2.8G | 70-200mm f/2.8G VR II

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>>...if you chimp a lot, you often have to wait for
>"green light off" to
>>start viewing the last few photos...
>
>I've been busted. That's it, I'm changing my name to
>SirChimpsAlot

You know what's embarrassing, to be at a shoot, see someone else's shots afterwards, find yourself in a few of them in the sidelines, and your head is always looking at the LCD instead of the view finder.

Not that it's ever happened to me of course, I'm just guessing it might be possible that might happen to someone else.


Linwood

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Interesting conclusions.

I shoot primarily sports with my D800. I only shoot RAW. To both cards. I do not use the fastest Sandisk cards. I have *never* hit the buffer limit on my D800. Not since day 1 back in April.

Therefore, I don't consider your conclusion valid.


>Some conclusions:
>
>1. Shooting sports RAW with a D800 is problematic.

>Shooting JPEG is really the only viable option for sports.

------
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I agree with your assessment: we are lucky the D800 shoots at only 4 fps. I suspect this low fps is NOT an accident. Nikon didn't want the D800 pausing in less than 2 seconds so it is very possible that they slowed the D800's burst rate.

Extrapolating from buffer emptying rates, we see an interesting set of performance values:

D800 RAW Write Speed

1000x CF UDMA 7 = 1 fps
700x CF UDMA 6 = 0.7 fps
95MB/s SD = 0.5 fps
100x DF or SD = 0.1 fps

Exceed any of these average frame rates and you will deplete the D800 buffer and ultimately cause the camera to pause. Stay below these rates, and the camera never pauses. The most interesting number: With a 100x card, maximum average sustained rate is somewhere near one picture every 10 seconds!

I don't chimp - my eyes aren't good enough for me to bother . But thanks for pointing that out!

--

Craig

>Extrapolating from buffer emptying rates, we see an
>interesting set of performance values:
>
>D800 RAW Write Speed
>
>1000x CF UDMA 7 = 1 fps
>700x CF UDMA 6 = 0.7 fps
>95MB/s SD = 0.5 fps
>100x DF or SD = 0.1 fps
>

I think that's a bit under-stated, as this appears to be uncompressed images, not lossless compressed which is what I think most use.

But it looks proportionally on track.


Linwood

Comments welcomed on pictures: Http://captivephotons.com

>Interesting conclusions.
>
>I shoot primarily sports with my D800. I only shoot RAW. To
>both cards. I do not use the fastest Sandisk cards. I have
>*never* hit the buffer limit on my D800. Not since day 1 back
>in April.
>
>Therefore, I don't consider your conclusion valid.
>

It all depends on how you shoot sports. If you never shoot more than 13 images in one burst or you take long pauses between bursts, your D800 will not pause. Just remember, regardless of card used, the D800 ALWAYS pauses after a burst of 13 images (or less if the buffer is partially full to start with) . That's why I say D800 RAW is not suitable for sports: The day I need a burst of 14 or more shots, the D800 will let me down.

The length of time until the buffer empties is dependent on the card being used. If, like you say, you use a medium speed card, you will have a 500x card or buffer to card transfer rate of about 1 frame every 2 seconds.

If you shoot in 7 frame bursts with 14 seconds between each burst, you will maintain an empty shot buffer and your D800 will never pause. If you shoot in 7 frame bursts with 7 seconds between each burst, you will start buffering images. If you maintain this average pace, your D800 will finally pause in 49 seconds.

If you switch to a single 1000x CF configuration which a faster 1 fps transfer rate and shoot 7 frame bursts with 7 seconds between each burst, your D800 pause in about 1 minute and 30 seconds.

Try it.

--

Craig

>It all depends on how you shoot sports. If you never shoot
>more than 13 images in one burst or you take long pauses
>between bursts, your D800 will not pause. Just remember,
>regardless of card used, the D800 ALWAYS pauses after a burst
>of 13 images (or less if the buffer is partially full to start
>with) . That's why I say D800 RAW is not suitable for sports:
>The day I need a burst of 14 or more shots, the D800 will let
>me down.

>Try it.
>

With the 1000x card I get 18 before the pause, and 13 with a slow SD card, but it's still on the order of 4 seconds.

It all depends on shooting style, whether this is "long enough". My point is that difference in 13 vs. 18 is not large, and at 4fps it's long enough for many shooting situations.

That those 18 shots are almost a gigabyte is much more relevant to me in terms of card choice.



Linwood

Comments welcomed on pictures: Http://captivephotons.com

I will retest with lossless compressed RAW!

If the D800 is not processor bound, compression will reduce the number of bytes written and speed things up. But if all CPU cycles are being used encoding and storing images, compression won't necessarily help because the CPU becomes the bottleneck.

Frankly, I think the D800 is processor bound some of the time since writing to two cards doesn't take much longer than one card. This suggests the D800 uses a significant number of processing cycles preparing an image.


Good experiment. Cheers.

--

Craig

>Frankly, I think the D800 is processor bound some of the time
>since writing to two cards doesn't take much longer than one
>card. This suggests the D800 uses a significant number of
>processing cycles preparing an image.

Try it. I think (based on observation not knowledge) that the write time is a combination of the card and subsystem, and not processor limited, and I think they designed it (either hardware or stupid software) so that it writes first to one card then to the other.

All testing I have done with uncompressed made everything run slower - buffer clear and download.

Linwood

Comments welcomed on pictures: Http://captivephotons.com

A key variable is card type.

CF UDMA generally requires fewer main processor cycles since the smart CF processor can offload some of the work. UDMA uses "cycle-stealing" - or more simply 'shared memory' - to let the main CPU and CF processors execute in parallel. UDMA was a popular hard disk standard in PC world a few years ago before the introduction of SATA.

Most SD controllers I've encountered are 'dumb'. Writing requires the main CPU to do most of the work.

--

Craig

Hi Perrone,

>D600 has two SD slots. D3s/D4 have 2 CF slots. Pick your
>poison.

While the D3 Series bodies have 2 CF slots, the D4 has 1 CF slot and 1 XQD slot.
Good Luck and Enjoy your Nikons!

Best Regards,
Marty

I retested with compressed RAW. The results are are a little disappointing.

Using compressed raw versus raw yields a 15 shot buffer versus 13. But both are estimates. If the images you shoot have complex detail, the buffer will be smaller in both cases.

The disappointing part: The time to clear the image buffer after it fills up remains close to 1 fps with a 1000x CF card. It is slightly better with compressed raw since the D800 will occasionally (and randomly) save a burst of 2 images in one second and then fall back to 1 fps.

The definitely points to the fact that D800 is CPU bound. It confirms statements raised by other reviewers suggesting the D800 processor is underpowered.

More supporting evidence:

1) I borrowed a friend's Canon 5D MkIII. His buffer is written continuously at 3 frames per second meaning that it is almost impossible to have his camera lock up.

2) With a USB3 connection on my computer, I can write to a 1000x card @ 4 fps.

Very embarrassing for Nikon if you ask me. Putting a cheap CPU in a $3000 camera seems like poor judgement.

--

Craig

Hi Craig,

>More supporting evidence:
>
>1) I borrowed a friend's Canon 5D MkIII. His buffer is written
>continuously at 3 frames per second meaning that it is almost
>impossible to have his camera lock up.

The 5D Mk III at full resolution creates 27.1 MB Raw files compared to the D800's 74.4MB Raw Uncompressed.
This is almost 3 times the information that must be transferred to the card per unit time.
Even shooting Lossless Compressed at 41.3MB the files are still 52% larger than the files from the 5D Mk III.

If you check the 5D Mk III Manual the maximum burst rate is listed at 13 (18) which surrounds the D800'ss 16 - 17 maximum.

If you compare the buffers at jpeg Large Fine the 5D Mk III creates 7MB files with a maximum Buffer Capacity of 65 images compared to the D800's 16.3MB files with a capacity of 56 images or Jpeg Normal where the D800 creates 9.1MB files with a maximum Buffer capacity of 100 images.

>Very embarrassing for Nikon if you ask me. Putting a cheap
>CPU in a $3000 camera seems like poor judgement.

Hardly given the huge difference in file size!
Comparing the two is like comparing Apples to Oranges.
The 5D Mk III maximum is 6 FPS compared to the D800's 4 FPS or 5 FPS (1.2 Crop (25MP)) or 6 FPS (DX Crop mode (15.3MP)).
Keep in mind that the 5D Mk III is still priced at $300.00 more than the D800 even with a $200.00 Canon Instant Rebate.
Good Luck and Enjoy your Nikons!

Best Regards,
Marty

>The definitely points to the fact that D800 is CPU bound. It
>confirms statements raised by other reviewers suggesting the
>D800 processor is underpowered.
...
>2) With a USB3 connection on my computer, I can write to a
>1000x card @ 4 fps.

I'd agree that the D800 is slower writing than I would hope, but it doesn't need to be the CPU, in fact I would argue the CPU itself is likely not the culprit simply because compressed vs. uncompressed seem of similar speed. If it were CPU bound writing, I would expect that compression would slow it down further.

But I would think it is the I/O mechanisms attached to the CPU, so it pretty much comes out the same. AS a simple example, they COULD have made it write to the SD and CF in parallel, but they clearly do not, as write times for primary+backup are nearly exactly additive, even with very slow cards (i.e. if it were the CPU that was causing it to be additive as opposed to writing separately, the difference would fade as write speeds decreased).

Frankly that (lack of parallel backup performance) is a bigger disappointment, as it seems so premeditated.

Linwood

Comments welcomed on pictures: Http://captivephotons.com

I have been using high-speed 32GB SD cards for overflow in my two D800e bodies for several months. This week I pulled the SD cards out. I will no longer have overflow because it is confusing. If you are out shooting and get into an exciting series of shots and run into overflow, you have no idea that it happened. You just find yourself wondering how you have so many shots left. I have never had but one CF card failure. I will just live with that possibility in the future. Since I do not make my living with the D800e bodies, I can afford to be casual about overflow or backup.

I like to keep it simple!

Larry Jordan

D800E, 14-24, 50, 24-70, 70-180 Micro, 70-200, 80-400mm AF-S

Website:
http://larryjordan.smugmug.com/