p.3 #1 · Sony A9III CFE-a Memory Card Performance Data
dclark wrote:
Since the Z8 buffer size is the same, 21 Frames, for all RAW types, that seems to indicate the Nikon stores unprocessed RAW data in the buffer. Sony seems to compress the data before storing in the buffer for the lossy compressed and stores unprocessed RAW data for lossless compressed and uncompressed. Nikon Z8 lossless compressed is about the same file size Sony A1 uncompressed and they both hit the buffer at ~80 frames. Sony lossless compressed is smaller and hits the buffer at ~105 frames.
It is not documented by Nikon how fast it captures frames once the buffer is filled, so one would need to make some assumptions to get an estimate. Also there is no data I see for how fast the buffer is cleared once capture stops. It's a small buffer so I assume it should be very quick.
If I had a Z8 I would make the measurements (it's easy), although I think it's buffer limits are probably not operationally important to the way I operate a camera. At 20fps the same is true for the A1 or the A9III. At 30fps, which the Z8 cannot do, the Sony A1 is somewhat limiting and the A9III limit is beyond anything I require. I believe the main operational lesson of this data for the A9III is that I would normally use 120fps or 60fps only in boost. There may be a few situations where operating at 120 or 60 fps in conjunction with the pre-capture may be useful. Others may have different methods and will reach other conclusions, but I believe all the information needed for such decisions is presented.
Anyone using any of these cameras does not have much of a basis to blame the camera if you're not getting the shot. IMO, the weak link is the human attached to the finger that is pushing the shutter button. ...Show more →
I found using 120FPS on the A9III to be severely limiting. You need to have a very specific goal and strictly follow it. My example is I wanted to try 120FPS with precapture on an osprey entering the water. Just to try and get that perfect moment as the talons just touch the water without even breaking the surface. But old habits die hard and on my first couple attempts I fired during the dive and the buffer was done and when the osprey hit, precapture was probably giving me 5FPS as you show in the data.
I found that 60FPS with precapture was useable as a general setting most of the time. My preferred mode was 30FPS with precapture on all the time. That was a good middle ground to not be running into buffer issues.
p.3 #2 · Sony A9III CFE-a Memory Card Performance Data
snapsy wrote:
Here are my rough estimates/calcs based on the specs in Nikon manual. Note HE is infinite per Nikon manual so I just entered a large value instead.
The estimated sustained buffer clearing rate would be the values in rows 7 and 8, or some derivative of it.
Today I did an actual measurement on my Z8 with a Delkin 325GB Black CFE (lossless raw). The "FPS After Burst" is the sustained FPS after the buffer becomes full. The results are very close to what I calculated above from the Z8 manual. Explanation of graphs below.
p.3 #3 · Sony A9III CFE-a Memory Card Performance Data
snapsy wrote:
Here are my rough estimates/calcs based on the specs in Nikon manual. Note HE is infinite per Nikon manual so I just entered a large value instead.
The estimated sustained buffer clearing rate would be the values in rows 7 and 8, or some derivative of it.
As I stated you can make some assumptions to fill in the missing information and make calculations. That is what you have done. You assumed that you can take the buffer size, the frame rate, and the number of frames captured when the buffer fills and compute the sustained frame rate once the buffer is filled. What if I told you the A9III at 120fps has a buffer of 156 frames that fills after 191 frames. What you you conclude the sustained rate would be?
I expect the assumption you have made is probably OK for the Z8.
As I said, if I had a Z8 I would make the measurement, not make the assumption.
p.3 #4 · Sony A9III CFE-a Memory Card Performance Data
snapsy wrote:
Today I did an actual measurement on my Z8 with a Delkin 325GB Black CFE (lossless raw). The "FPS After Burst" is the sustained FPS after the buffer becomes full. The results are very close to what I calculated above from the Z8 manual. Explanation of graphs below.
p.3 #6 · Sony A9III CFE-a Memory Card Performance Data
dclark wrote:
As I stated you can make some assumptions to fill in the missing information and make calculations. That is what you have done. You assumed that you can take the buffer size, the frame rate, and the number of frames captured when the buffer fills and compute the sustained frame rate once the buffer is filled. What if I told you the A9III at 120fps has a buffer of 156 frames that fills after 191 frames. What you you conclude the sustained rate would be?
I expect the assumption you have made is probably OK for the Z8.
As I said, if I had a Z8 I would make the measurement, not make the assumption. ...Show more →
I would say consider running the additional tests I hinted at the other day to suss out the A9 III differences you discovered between 120fps and 30fps. The Z8 estimates I made from Nikon's specs were from a single fps rate (20fps).
p.3 #7 · Sony A9III CFE-a Memory Card Performance Data
dclark wrote:
Hmmm.....what happened at frame ~80
Stall from the buffer-full condition. That's the inflection point from running at the rated 20fps burst to the 15.5fps sustained thereafter. My measurement for was 10 seconds, which is intentionally done to get a stable sustained fps sample after the buffer full condition.
p.3 #8 · Sony A9III CFE-a Memory Card Performance Data
snapsy wrote:
Stall from the buffer-full condition. That's the inflection point from running at the rated 20fps burst to the 15.5fps sustained thereafter. My measurement for was 10 seconds, which is intentionally done to get a stable sustained fps sample after the buffer full condition.
Yes, I misread your post and thought it was for compressed RAW. It's obviously labeled uncompressed.
p.3 #9 · Sony A9III CFE-a Memory Card Performance Data
arbitrage wrote:
I found using 120FPS on the A9III to be severely limiting. You need to have a very specific goal and strictly follow it. My example is I wanted to try 120FPS with precapture on an osprey entering the water. Just to try and get that perfect moment as the talons just touch the water without even breaking the surface. But old habits die hard and on my first couple attempts I fired during the dive and the buffer was done and when the osprey hit, precapture was probably giving me 5FPS as you show in the data.
I found that 60FPS with precapture was useable as a general setting most of the time. My preferred mode was 30FPS with precapture on all the time. That was a good middle ground to not be running into buffer issues....Show more →
120fps even with a bigger buffer is a tough use case because of the sheer number of photos you have to slog through. I mostly use my A9III at 30fps with precapture. I used 120fps when I was trying to capture hummingbirds in flight or similar things where the incredibly fast action also calls for an incredibly fast frame rate but you most certainly have to train your brain and finger to work differently in these cases.
For something like your example of the osprey, hitting the shutter right at the moment it is hitting the water is probably ideal if you have a decent-sized recapture turned on.
p.3 #10 · Sony A9III CFE-a Memory Card Performance Data
arbitrage wrote:
I found using 120FPS on the A9III to be severely limiting. You need to have a very specific goal and strictly follow it. My example is I wanted to try 120FPS with precapture on an osprey entering the water. Just to try and get that perfect moment as the talons just touch the water without even breaking the surface. But old habits die hard and on my first couple attempts I fired during the dive and the buffer was done and when the osprey hit, precapture was probably giving me 5FPS as you show in the data.
I found that 60FPS with precapture was useable as a general setting most of the time. My preferred mode was 30FPS with precapture on all the time. That was a good middle ground to not be running into buffer issues....Show more →
I thought of a feature and wanted to see if you think it might be useful in the field. What if the camera gave you the option to discard all the remaining photos in the buffer, as in not write them to the card, allowing you to shoot another 120fps burst without further delay? I'm thinking it could show you the first and last frame of the most recent burst (perhaps as a split-screen, with each side zoomed on the focus point), to let you quickly evaluate whether you likely got the sequence you wanted - if not, let you press a single button to discard all unwritten photos and return the camera to a fully empty buffer. Do you think this is something you would find useful and integrate into your shooting?
p.3 #11 · Sony A9III CFE-a Memory Card Performance Data
Shuttermuse has an interesting article about the best card for an A9iii and he recommends one with the highest sustained write speed ie the ProDigital Gold Type A card with a sustained write speed of 600mb/secBest memory cards for the A9iii -I was wrong
Can I ask what capacity cards would be recommended for an exciting day of wildlife action and how do you configure slots 1 and 2
For the A1 I use 160gb Sony card in Slot 1 with compressed RAW and 80gb in slot 2 for JPEG as back up which gives about 2200 images for each slot However I sort through the images each day and have never run out of space on the 160gb card with my shooting style which is short bursts
p.3 #12 · Sony A9III CFE-a Memory Card Performance Data
UKBob wrote:
Shuttermuse has an interesting article about the best card for an A9iii and he recommends one with the highest sustained write speed ie the ProDigital Gold Type A card with a sustained write speed of 600mb/secBest memory cards for the A9iii -I was wrong
Can I ask what capacity cards would be recommended for an exciting day of wildlife action and how do you configure slots 1 and 2
For the A1 I use 160gb Sony card in Slot 1 with compressed RAW and 80gb in slot 2 for JPEG as back up which gives about 2200 images for each slot However I sort through the images each day and have never run out of space on the 160gb card with my shooting style which is short bursts ...Show more →
This is why I have mentioned the Angelbird 1TB cards several times now when this topic comes up. They have a sustained write speed of 650MB/s. They have been discontinued but AngelBird did reply to my email request and indicated that a new version is in the works. I'd guess it will be PCIe 4.0 like the other new cards and hopefully have an even faster sustained write speed.
p.3 #13 · Sony A9III CFE-a Memory Card Performance Data
jhapeman wrote:
This is why I have mentioned the Angelbird 1TB cards several times now when this topic comes up. They have a sustained write speed of 650MB/s. They have been discontinued but AngelBird did reply to my email request and indicated that a new version is in the works. I'd guess it will be PCIe 4.0 like the other new cards and hopefully have an even faster sustained write speed.
Can you measure the performance of the Angelbird 1TB card and post for comparison the same curves as are posted in this thread for the Lexar, Delkin and Sony cards. Those cards showed no difference in performance, even though they differ in their specs. As noted, that is even true for the Lexar Gold and Silver, and the Lexar Gold lists minimum write speed spec that is better than the Angelbird. Also, it has been rumored that the Angelbird was withdrawn because it failed to qualify VPG-200 certification. I don't have much confidence in any of the specs which is why I prefer to make measurements. A set of actual measurements for the Angelbird would be very interesting. I tried to get a card to test but could not buy, rent, or borrow one.
p.3 #14 · Sony A9III CFE-a Memory Card Performance Data
I'm wondering why no camera manufacturer offers RAID0-like card access? Of course not on the sector level but on the file level. I.e. odd files go on the card 1 and even files go on the card 2. Even if you lose a card - you'd still have half of your files. That would reduce the image dump time in half.
p.3 #15 · Sony A9III CFE-a Memory Card Performance Data
docusync wrote:
I'm wondering why no camera manufacturer offers RAID0-like card access? Of course not on the sector level but on the file level. I.e. odd files go on the card 1 and even files go on the card 2. Even if you lose a card - you'd still have half of your files. That would reduce the image dump time in half.
That would help image write time only if it is limited by card bandwidth, not camera electronic processing. It appears to be limited by camera electronics ability to process files not the card's bandwidth..
p.3 #16 · Sony A9III CFE-a Memory Card Performance Data
dclark wrote:
That would help image write time only if it is limited by card bandwidth, not camera electronic processing. It appears to be limited by camera electronics ability to process files not the card's bandwidth..
I'm not sure, but I thought the files are already processed (in the manufacturer-specific raw format) when they get into the buffer, no? If we're dealing with a slow system bus, then switching to the CFeA 4.0 cards won't make any difference
p.3 #17 · Sony A9III CFE-a Memory Card Performance Data
docusync wrote:
I'm not sure, but I thought the files are already processed (in the manufacturer-specific raw format) when they get into the buffer, no? If we're dealing with a slow system bus, then switching to the CFeA 4.0 cards won't make any difference
There are a number of things that need to be done to prepare a file for writing onto the memory card, including things like adding metadata, adding jpeg image that is processed according to the users settings, possibly noise reduction, possibly compression, etc. It appears that in the Sony A1 compression is completed before the file is written into the buffer for one type of compression, but not the other (see the linked thread). Regardless, all the processing operations take part of the bandwidth of the processor and may be the limiting factor in the sustained throughput. The data presented here seems to show that the sustained throughput is independent of the card. That would imply, as you stated, that in order to see the benefit of faster cards, the cameras electronics needs to be improved.
p.3 #18 · Sony A9III CFE-a Memory Card Performance Data
dclark wrote:
There are a number of things that need to be done to prepare a file for writing onto the memory card, including things like adding metadata, adding jpeg image that is processed according to the users settings, possibly noise reduction, possibly compression, etc. It appears that in the Sony A1 compression is completed before the file is written into the buffer for one type of compression, but not the other (see the linked thread). Regardless, all the processing operations take part of the bandwidth of the processor and may be the limiting factor in the sustained throughput. The data presented here seems to show that the sustained throughput is independent of the card. That would imply, as you stated, that in order to see the benefit of faster cards, the cameras electronics needs to be improved.
p.3 #19 · Sony A9III CFE-a Memory Card Performance Data
docusync wrote:
I'm not sure, but I thought the files are already processed (in the manufacturer-specific raw format) when they get into the buffer, no? If we're dealing with a slow system bus, then switching to the CFeA 4.0 cards won't make any difference
There is a long image pipeline the raw sensor data has to undergo before it becomes a fully-formed image read for writing. This includes the various flavors of noise reduction (spatial filtering, impulse noise removal), WB scaling, PDAF pixel interpolation, pixel remapping interpolation, etc... and that's just the raw bayered data. Even raws then undergo the full debayered pipeline since they all included embedded jpgs. For a general idea of what this pipeline entails here's the documentation of RawTherapee's pipeline:
Think about how long it takes for a computer-based raw processor to render a single raw image and then multiply that by a camera's continuous frame rate and you'll get a sense for how computationally and data intensive the specialized imaging ASICs in cameras are, and why they are often the bottleneck in buffer clearing performance.
p.3 #20 · Sony A9III CFE-a Memory Card Performance Data
snapsy wrote:
Think about how long it takes for a computer-based raw processor to render a single raw image and then multiply that by a camera's continuous frame rate
I never thought about this from a "general purpose" computer perspective, but you're absolutely right, it must be a seriously powerful server to process 24Mpx 14bit images at 120 fps, especially considering the pipeline mentioned in RawTherapee.
