Help with D850 Buffer Issue?

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tigger4t

tigger4t

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Hi,

I have just bought a used Nikon D850 and shooting in Large RAW 14bit Lossless Compressed files it gives me only 14 shots in the buffer when I half press the shutter release so it's not even testing the transfer rate to the card - which is a 128Gb Sandisk Extreme SDXC 150 Mb/s. I have yet to buy an XQD card as I still have the D850 on 14 day approval but I am not aware the the transfer rate of the card is an issue as (a) I am not actually shooting and (b) when I tried a much slower SD card in the slot the buffer size stayed the same at 14.

By comparison, my D7200 gives me 19 frames in the buffer and my D800E gives me 14 using the same card. I know that the D850 has much bigger files but I would still expect some improvement over my older cameras if not the 51 according to the manual (albeit with an XQD card).

Is the camera actually taking the transfer speed into consideration before I shoot or do I have a problem?

**UPDATE** After a hard reset with the same image settings as above the D850 is giving me 27 in the buffer which reduces to 20 if I turn Auto-ISO on.

All advice gratefully received.

Simon
 
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I think that the card is holding the D850 back. Don't forget that the 150mb/s is most likely the read speed, not the write speed. It is a relatively recent thing for the read and write speeds to be shown in the card and if you look at the cards that do, the read speed is the faster one. Write speed of the middling type of SD cards is around 50% of the read speed.

Do you know anyone with an XQD card to try? If you do, make sure it is a G series one and not the earler and slower ones. The M series XQD cards have a read speed of 400mb/s, but the write speed is only 150mb/s. G series is 400mb/s for both about 6x faster than your SD card. The buffer will write imges that much faster so ought to get to the higher numbers.
 
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dabhand16 said:
I think that the card is holding the D850 back. Don't forget that the 150mb/s is most likely the read speed, not the write speed. It is a relatively recent thing for the read and write speeds to be shown in the card and if you look at the cards that do, the read speed is the faster one. Write speed of the middling type of SD cards is around 50% of the read speed.

Do you know anyone with an XQD card to try? If you do, make sure it is a G series one and not the earler and slower ones. The M series XQD cards have a read speed of 400mb/s, but the write speed is only 150mb/s. G series is 400mb/s for both about 6x faster than your SD card. The buffer will write imges that much faster so ought to get to the higher numbers.
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Thanks Graham - I've just found a D850 review on the DLSR Bodies website which confirms your view i.e.

"Let's talk about the most likely scenario raw shooters would be using: 14-bit Lossless Compressed NEF with the fastest available cards. With just an XQD card in the camera I'm hitting just above 50 shots before the buffer burps. Continuous shooting above that will be "as fast as the card writes. Let's try a state-of-the-art UHS-II SD card with no XQD card in the camera: low 20's."

I don't know anyone locally who would have an XQD but I have raised the issue with London Camera Exchange and they might possibly lend me one to test the body. Maybe I just need to bite the bullet and buy an XQD card as I am still hoping that a D850 will give me benefits in terms of AF performance and image quality compared with my D800E and D7200.

Has anyone used a CFExpress card in a D850 with write speeds of 1200 Mb/sec? It seems that it was made possible in Firmware v1.20?
 
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Keep in mind the buffer size is just that, the number of images that can be written to the buffer with the current camera settings, and there are a number of camera settings that impact the buffer capacity. It doesn't have anything to do with the speed of the card. The faster the card the faster the buffer will clear so the more shots you can take before the fps slows down. The D850 will not be able to take advantage of the speeds of the fastest CFexpress cards but I don't see any reason not to purchase CFE cards instead of XQD unless you can find really good deals on XQD. I don't have a D850 but my D500 and my Z6ii perform much better with XQD than with SD cards and they perform a little better yet with CFE cards.

Card speed comparisons get pretty tricky. You need to find the write speed of cards and better yet the continuous minimum write speed. Write speed spec might be given for the maximum write speed but the card will slow down after the initial write burst, a card with a fast continuous write speed will continue to write images at that speed. The newest cameras can take advantage of the fast write speed so having a fast card can give more shot before the fps starts to slow.
 
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So I am currently shooting both the D500 and the D850, with a recent emphasis on the full frame. I have Sony Tough XQD and SanDisk SD cards in both, and I have tried CFexpress cards as well. Using the XQD cards, I have never hit the buffer on the D500. With the D850, the buffer is not as deep on the D500, and I have hit it once or twice. I generally do not shoot extended continuous for a great length of time, but more in bursts. I have not noticed any change in performance using CFexpress (Delkin Black) in the 2 cameras, but have noted faster performance in downloading to my Mac. I have tried just the SD cards and it’s my perception that the D850 is slower than with the XQD. So I would agree that either an XQD or CFexpress should perform better than an SD. There is always the caveat that If you had the fastest SD card and a dog slow XQD/CFexpress that you might see it flipped. My perception.
 
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Butlerkid said:
The D850 is an outstanding camera. Do you also have the Nikon grip? If so, the D850 is, IMHO, the best all around camera ever made. The grip enables faster frames per second. Get an XQD or CFe card, all firmware updates, and let 'er rip!
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Thanks for your feedback but no, I don't have a Nikon grip but was thinking of getting an off-brand version to keep the costs down and other than build quality / weather sealing there doesn't appear to a performance issue with off-brand versions. Increasing the frame rate just puts more pressure on the buffer though I guess
 
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MartyD said:
Keep in mind the buffer size is just that, the number of images that can be written to the buffer with the current camera settings, and there are a number of camera settings that impact the buffer capacity. It doesn't have anything to do with the speed of the card. The faster the card the faster the buffer will clear so the more shots you can take before the fps slows down. The D850 will not be able to take advantage of the speeds of the fastest CFexpress cards but I don't see any reason not to purchase CFE cards instead of XQD unless you can find really good deals on XQD. I don't have a D850 but my D500 and my Z6ii perform much better with XQD than with SD cards and they perform a little better yet with CFE cards.

Card speed comparisons get pretty tricky. You need to find the write speed of cards and better yet the continuous minimum write speed. Write speed spec might be given for the maximum write speed but the card will slow down after the initial write burst, a card with a fast continuous write speed will continue to write images at that speed. The newest cameras can take advantage of the fast write speed so having a fast card can give more shot before the fps starts to slow.
Click to expand...
Thanks - interesting that you mention that the D850 won't be able to take advantage of the CFE faster speeds (write speed of 1400 Mb/sec c/w 400 for the XQD card) - do you know the limitation on D850s write speed rather than that of the card? I have raised a support ticket with Nikon to ask the question.
 
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Fishboy1952 said:
So I am currently shooting both the D500 and the D850, with a recent emphasis on the full frame. I have Sony Tough XQD and SanDisk SD cards in both, and I have tried CFexpress cards as well. Using the XQD cards, I have never hit the buffer on the D500. With the D850, the buffer is not as deep on the D500, and I have hit it once or twice. I generally do not shoot extended continuous for a great length of time, but more in bursts. I have not noticed any change in performance using CFexpress (Delkin Black) in the 2 cameras, but have noted faster performance in downloading to my Mac. I have tried just the SD cards and it’s my perception that the D850 is slower than with the XQD. So I would agree that either an XQD or CFexpress should perform better than an SD. There is always the caveat that If you had the fastest SD card and a dog slow XQD/CFexpress that you might see it flipped. My perception.
Click to expand...
Thanks - I think my technique could certainly do with some work in terms of burst shooting. While shooting Ospreys fishing a few weeks ago my D7200 was constantly hitting the buffer limit as my finger didn't leave the shutter release during it's dive but that's probably not that surprising. I'll wait for Nikon to respond but it seems odd that they should enable CFE in the last(?) firmware upgrade if there is no real benefit of using the faster cards.
 
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tigger4t said:
Has anyone used a CFExpress card in a D850 with write speeds of 1200 Mb/sec? It seems that it was made possible in Firmware v1.20?
Click to expand...

FWIW, I updated my D850 firmware so it would accept CFe cards. Not because I wanted any exra speed, I've seen on here that th D850 hardware is a limiting factor, and it won't be much faster than XQD - if at all, but the CFe cards are now geting cheaper than XQD.

I don't need the bigger capacities that the CFe cards have either. A while ago I got 128GB CFe cards for just over £100 where a Sony 64GB XQD would have cost about £145.
 
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Angelbird 512Gb SE cfexpress card is a good bargain for size vs performance. Minimum write speed is 800MB/sec when device supports that speed. Retails for around 150GBP at Wexphoto.
Fast V90 rated sd cards are much more expensive and only have minimum write speed of 90MB/sec.

With D850, you can update firmware from sd if cfexpress not yet supported. Need to be careful on Z6/Z7 i with only one slot
 
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tigger4t said:
Thanks for your feedback but no, I don't have a Nikon grip but was thinking of getting an off-brand version to keep the costs down and other than build quality / weather sealing there doesn't appear to a performance issue with off-brand versions. Increasing the frame rate just puts more pressure on the buffer though I guess
Click to expand...
Remember grip needs D5 type en-el18 battery to get the faster frame rate. Those batteries and chargers, even 3rd party ones are pricey go get.
 
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dabhand16 said:
FWIW, I updated my D850 firmware so it would accept CFe cards. Not because I wanted any exra speed, I've seen on here that th D850 hardware is a limiting factor, and it won't be much faster than XQD - if at all, but the CFe cards are now geting cheaper than XQD.

I don't need the bigger capacities that the CFe cards have either. A while ago I got 128GB CFe cards for just over £100 where a Sony 64GB XQD would have cost about £145.
Click to expand...
Thanks that's useful information - from what I've read this morning it seems that a single card setup maximises the in-camera write speed which is interesting but maybe I'm overthinking this!
 
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tigger4t said:
Thanks - interesting that you mention that the D850 won't be able to take advantage of the CFE faster speeds (write speed of 1400 Mb/sec c/w 400 for the XQD card) - do you know the limitation on D850s write speed rather than that of the card? I have raised a support ticket with Nikon to ask the question.
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I don't know the maximum write speed of the card interface on the D850 and there are a number of issues that could impact the write speed. When the D850 was released I don't believe the specifications for CFexpress storage technology had even been finalized yet. I know one of the differences between XQD and CFE is that XQD can only use 1 PCIe lane to write data and CFE can use 4 PCIe lanes to write data.

I have tried to do a number of tests with my D500, Z6, and Z6ii to determine if there is any advantage to faster memory cards. It is pretty much impossible to test that on the D500 because the buffer depth is so big that you can take 200 shots on XQD or CFE cards and that is the max the camera will allow. My Z6 will show better performance with faster CFE cards but not proportional to the increased speed of the cards.

The SanDisk SD Extreme Pro labeled 300MB/s can write up to 260MB/s the ProGrade Digital CFexpress Cobalt series has a minmum sustained write speed of 1400 MB/s. A V30 SD card can write 4k video so it is capable of a 30MB/s sustained write speed, a V90 SD card can write 8k video so it is capable of 90MB/s sustained write speed. A V90 SD card is almost as expensive as a CFE card and is not nearly as fast.

There will be a bottleneck at some point in writing images to a storage device. You can't do anything about the bottleneck created by the technology in the D850 but you don't want to add an addition bottleneck caused by the card.
 
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I did a little test on my D500 to compare the usable performance difference between an SD card and an XQD card. The camera was set on 14bit RAW lossless compressed. Here are the results.

CameraCardBuffer ShowsTime to FPS Slow in secondsTime to Finish Write in secondsTotal Time in secondsImages captured
D500SanDisk 170MB/s SD29481240
D500Sony XQD 400MB/s 128Gb2920020200

With a 170MB/s SD card I could capture 40 images before the buffer filled and the FPS slowed, it then took an additional 8 seconds to write the buffer to the card. I also tested it with a 95MB/s SD card and it pretty much performed the same. I think since both cards are labeled V30 their sustained write speed is probably the same.

With a Sony XQD 400MB/s card, I could shoot 200 frames and then the camera limitation kicked in. I could not detect that there was any additional time required to write the buffer to the card. The buffer value decreased to 17 while shooting and stayed at that level until getting close to 200 images and then it quickly went to 0. The D500 performed the same way when I used a fast CFexpress card instead of the Sony XQD but there really isn't any way to test it. I believe the D500 might be able to capture many more than 200 images in a burst but Nikon has limited it 200.

I did a similar test on my Z6ii and the test is below if you are interested. The Z6ii is limited to 200 images in a burst. I have not performed any tests with my Z9.

CameraCardBuffer ShowsTime to FPS Slow in secondsTime to Finish Write in secondsTotal Time in secondsImages captured
Z6iiSanDisk 90MB/s SD467212888
Z6iiSanDisk 170MB/s SD467212890
Z6iiLexar XQD 400MB/s46131124157
Z6iiSony XQD 400MB/s 128Gb46131124166
Z6iiSanDisk Cfexpress46161127197
Z6iiAngelbird Cfexpress4616622200
Z6iiProGrade Cobolt Cfexpress4616824200
 
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MartyD said:
I did a little test on my D500 to compare the usable performance difference between an SD card and an XQD card. The camera was set on 14bit RAW lossless compressed. Here are the results.

CameraCardBuffer ShowsTime to FPS Slow in secondsTime to Finish Write in secondsTotal Time in secondsImages captured
D500SanDisk 170MB/s SD29481240
D500Sony XQD 400MB/s 128Gb2920020200

With a 170MB/s SD card I could capture 40 images before the buffer filled and the FPS slowed, it then took an additional 8 seconds to write the buffer to the card. I also tested it with a 95MB/s SD card and it pretty much performed the same. I think since both cards are labeled V30 their sustained write speed is probably the same.

With a Sony XQD 400MB/s card, I could shoot 200 frames and then the camera limitation kicked in. I could not detect that there was any additional time required to write the buffer to the card. The buffer value decreased to 17 while shooting and stayed at that level until getting close to 200 images and then it quickly went to 0. The D500 performed the same way when I used a fast CFexpress card instead of the Sony XQD but there really isn't any way to test it. I believe the D500 might be able to capture many more than 200 images in a burst but Nikon has limited it 200.

I did a similar test on my Z6ii and the test is below if you are interested. The Z6ii is limited to 200 images in a burst. I have not performed any tests with my Z9.

CameraCardBuffer ShowsTime to FPS Slow in secondsTime to Finish Write in secondsTotal Time in secondsImages captured
Z6iiSanDisk 90MB/s SD467212888
Z6iiSanDisk 170MB/s SD467212890
Z6iiLexar XQD 400MB/s46131124157
Z6iiSony XQD 400MB/s 128Gb46131124166
Z6iiSanDisk Cfexpress46161127197
Z6iiAngelbird Cfexpress4616622200
Z6iiProGrade Cobolt Cfexpress4616824200
Click to expand...
Thanks for the test, that's really useful and helps inform my decision on what card to buy. My current thinking is to buy a 512 Gb CFE card and just leave the SD slot empty. But keep some cards as backup in my bag.
 
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I don’t believe I read it above (if I missed it and this is a repeat of someone else I’m sorry) but another option to help with buffer is to change from 14 bit to 12 bit. Smaller file size will deepen buffer. I used to do that when I photographed airshows. Never really noticed a major difference in picture quality.
I had an after market grip with my D850 (actually still have it). Worked with no issues. I used Nikon battery and battery door with it. Just make sure you grab correct grip because some won’t add the two fps.
 
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Having a D850 I would recommend you go with the Nikon Vertical Grip, you can find them used for a reasonable cost. Both of my cards in the D850 are cards that are at least
having a write speed of 1200 MB/s and a read speed of 1700 MB/s.
 
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Bennvdm said:
Angelbird 512Gb SE cfexpress card is a good bargain for size vs performance. Minimum write speed is 800MB/sec when device supports that speed. Retails for around 150GBP at Wexphoto.
Fast V90 rated sd cards are much more expensive and only have minimum write speed of 90MB/sec.

With D850, you can update firmware from sd if cfexpress not yet supported. Need to be careful on Z6/Z7 i with only one slot
Click to expand...
Thanks for the Angelbird recommendation - is that what you use in your D850 or were you just pointing out a good deal ? Nikon have just sent me a link to their memory card compatibility page which only includes the more well known brands of course.

 
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I use it on my z6 ii after having card hot warnings on my lexar 64gb cfexpress cards. Runs a lot cooler than the Lexar, ironically most noticeable on the Lexar cfexpress reader. I also tested it on my D500 after upgrading the firmware and works fine.
The D850 is a bit newer than the D500, so might even work a bit faster than on the D500. I am contemplating replacing the D500 with an used D850 as there are good deals to be had.

It is also a recommended card per Angelbirds compatibility checker for the D850.

Camera Compatibility

www.angelbird.com www.angelbird.com

Angelbird cfexpress cards are also the only cards with upgradable firmware afaik, with the catch being that you need an angelbird card reader to perform the update. There was several updates for older cards for better Z9 and D850/D500 compatibility.
The only complaints I have seen thus far was wit the Mk1 cards on the Z9, that have a not compatible rating on Angelbirds compatibility checker.
 
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tigger4t said:
Hi,

I have just bought a used Nikon D850 and shooting in Large RAW 14bit Lossless Compressed files it gives me only 14 shots in the buffer when I half press the shutter release so it's not even testing the transfer rate to the card - which is a 128Gb Sandisk Extreme SDXC 150 Mb/s. I have yet to buy an XQD card as I still have the D850 on 14 day approval but I am not aware the the transfer rate of the card is an issue as (a) I am not actually shooting and (b) when I tried a much slower SD card in the slot the buffer size stayed the same at 14.

By comparison, my D7200 gives me 19 frames in the buffer and my D800E gives me 14 using the same card. I know that the D850 has much bigger files but I would still expect some improvement over my older cameras if not the 51 according to the manual (albeit with an XQD card).

Is the camera actually taking the transfer speed into consideration before I shoot or do I have a problem?

**UPDATE** After a hard reset with the same image settings as above the D850 is giving me 27 in the buffer which reduces to 20 if I turn Auto-ISO on.

All advice gratefully received.

Simon
Click to expand...
That card is a UHS-I SD card which has a peak write speed in the camera of around 72 MB/s. In contrast, a fast UHS-II SD card (Sandisk Extreme Pro 300 MB/s UHS-II) will be around 140 MB/s and a fast CF Express card around 220 MB/s in that camera. A slow CFExpress card may be in the 90 MB/s range, so get a fast CFEXpress card like Delkin Black, Delkin Power, or ProGrade Cobalt.

It would be even slower if you are writing RAW + JPEG - the files are written sequentially.

Keep in mind the file size of the D850 is much larger than a D7200. That means the buffer fills faster unless you have a very fast card.
 
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