A7R3 - Best Choice SD Card for Slot 2???

Started 11 months ago | Discussions
oliveview Forum Member • Posts: 55
A7R3 - Best Choice SD Card for Slot 2???

So, I bought two top of the line UHS-2 300/300 Sony SD cards for the new camera. Both, 128gig. However, knowing that slot 2 doesn't exploit those speeds, I realize that I'm entirely wasting one of those cards in that slot. I've looked through the instruction manual, and it only mentions UHS-I for slot two, but with no mention of actual max read/write speeds.

Does anyone know what slot 2 maxes out at?

I'd like to just buy a third, cheaper SD card for that purpose, and therefore use the two ultra-fast UHS-2 cards in slot 1. But how low can I go? 30megs/sec?

Thanks!

Jekabs Contributing Member • Posts: 697
Re: A7R3 - Best Choice SD Card for Slot 2???
1

Multiple tests say the A9 can do around 70MB/s when recording to both slots simultaneously, or to the UHS-I slot. A7rIII, which shares most of the processing electronics, probably does about same.

So you probably want to have the top of the line UHS-I card in the second slot, if you are using dual slot recording for backup. Something like Sandisk 95MB/s or similar. Or you can go with slow UHS-II cards, like Sony M series, which are much cheaper than G series.

Personally, I decided against the fastest UHS-II cards in my A7rIII. They are still relatively expensive and would be of no benefit for what I shoot. The buffer is large enough for anything I can think I would use it for and camera is mostly operational while clearing the buffer, unlike A7rII. Also, it is pointless to have fast card if you will be mostly writing to both slots for backup, because the second slot will be the bottleneck anyway.

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OP oliveview Forum Member • Posts: 55
Re: A7R3 - Best Choice SD Card for Slot 2???
1

Thanks so much. I probably over-bought with the two UHS-II cards, but I'm kind of in the camp that likes to future-proof a little. So, I don't mind too much. Plus, much of the cost was in the jump up to 128gigs, and I almost wish that I had gone for 256 now. But I digress...

I was curious about that dual slot write bottleneck. But is that absolutely so? If I'm writing RAW files only to the fast slot one, and only JPEGS to slot two, is that slower slot really going to drag things down that much? If I were writing RAW to BOTH card slots simultaneously, obviously that would be an issue.

teddoman
teddoman Senior Member • Posts: 2,483
Re: A7R3 - Best Choice SD Card for Slot 2???

Jekabs wrote:

Multiple tests say the A9 can do around 70MB/s when recording to both slots simultaneously, or to the UHS-I slot.

This suggests the buffer does act as a bottleneck. Do you have a link? Love to read more.

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Jeff Sereno
Jeff Sereno Regular Member • Posts: 151
Re: A7R3 - Best Choice SD Card for Slot 2???
2

oliveview wrote:

I was curious about that dual slot write bottleneck. But is that absolutely so? If I'm writing RAW files only to the fast slot one, and only JPEGS to slot two, is that slower slot really going to drag things down that much? If I were writing RAW to BOTH card slots simultaneously, obviously that would be an issue.

Interesting question.

I currently use a Lexar 1000x UHS-II 128GB card in Slot 1 and a SanDisk Extreme (not Pro) V30 UHS-I 128GB card in slot 2 on my A7Riii.

SanDisk Extreme (not Pro) V30 UHS-I 128GB on the left (approx AUD$90) and the Lexar 1000x UHS-II 128GB on the right (approx AUD$140).

The Lexar in my case is definitely faster than the SanDisk card, though I have not run any formal benchmarks - you can just see it in general read/write operations on a PC.

Doing the completely unscientific filling the buffer test on my A7Riii, and starting the stopwatch at the first slow snap (approximately 80 images, RAW+JPEG, full res, X.FINE mode) and then stop the clock when the last image has finished writing:

  • For JPEG on Lexar Slot 2, RAW on SanDisk Slot 1: 54.47 seconds
  • For RAW on Lexar Slot 2, JPEG on SanDisk Slot 1: 49.42 seconds
  • For JPEG on Lexar Slot 1, RAW on SanDisk Slot 2: 54.56 seconds
  • For RAW on Lexar Slot 1, JPEG on SanDisk Slot 2: 47.77 seconds

So the largest difference was just under 7 seconds. The Lexar shows that is also performs better than the SanDisk even on the UHS-I-only slot 2.

Images appear to be written sequentially by the A7Riii, so one card will not finish writing all images before the other. They will always ultimately finish together.

Repeating the fill-the-buffer test with RAW + JPEG being written to the ONE card in Slot 1 only, shows:

  • Lexar: 62.47 seconds
  • SanDisk: 86.05 seconds

Most online reviews seem to pit the Lexar 1000x writing speed at between 75 and 85MB/s, and the SanDisk Extreme V30 (not Pro) writing speed at between 62 and 64MB/s.

This shows that the camera is very much as fast as the slowest card in either slot when writing to both at the same time. Since both these cards can be had relatively cheap, in my books it would not be worth buying a card that can only do 30MB/s when the UHS-I slot on the camera can do at least twice that speed. That said, if you only ever take single shots and never burst shots, then it probably won't affect you at all anyway.

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OP oliveview Forum Member • Posts: 55
Re: A7R3 - Best Choice SD Card for Slot 2???

Wow, Jeff. Thanks for that great effort and time. Very interesting, indeed. I think I'll pick up a moderately fast third card for slot 2, and do as I was thinking, and use both my ultra fast ones only for slot 1.

Steve W Veteran Member • Posts: 4,158
Re: A7R3 - Best Choice SD Card for Slot 2???

oliveview wrote:

So, I bought two top of the line UHS-2 300/300 Sony SD cards for the new camera. Both, 128gig. However, knowing that slot 2 doesn't exploit those speeds, I realize that I'm entirely wasting one of those cards in that slot. I've looked through the instruction manual, and it only mentions UHS-I for slot two, but with no mention of actual max read/write speeds.

Does anyone know what slot 2 maxes out at?

I'd like to just buy a third, cheaper SD card for that purpose, and therefore use the two ultra-fast UHS-2 cards in slot 1. But how low can I go? 30megs/sec?

Thanks!

I think it all depends on how you plan to shoot and I've had questions around this as well.

I heard of one user who bought two fast cards and just writes to the slot 1 all the time. First they fill up the first card, then swap and then they fill up the second card. They get the faster speed but no redundancy. Interesting approach.

I'm using the approach where I have a fast SanDisk Extreme Pro UHS-II 300 MB/s card in slot 1 (128GB) and a SanDisk Extreme Pro UHS-I 95 MB/s card in slot II.  B&H was and still maybe selling a bundle like this.

My Key question is what is faster in slot II?  A fast UHS-I card optimized for that interface or a UHS-II card, that is running in UHS-I mode? I can't tell because I never see a spec for a UHS-II card running in UHS-I mode. Does anybody know?

If your running in redundant mode is it best to just use two Fast UHS-I cards, since that will set the speed  in this mode? Or will using to UHS-II card provide the best speed?  Some of these combination really need to be tested to get a better feeling on what to buy.

Steve W

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Steve W Veteran Member • Posts: 4,158
Re: A7R3 - Best Choice SD Card for Slot 2???

Jeff Sereno wrote:

oliveview wrote:

I was curious about that dual slot write bottleneck. But is that absolutely so? If I'm writing RAW files only to the fast slot one, and only JPEGS to slot two, is that slower slot really going to drag things down that much? If I were writing RAW to BOTH card slots simultaneously, obviously that would be an issue.

Interesting question.

I currently use a Lexar 1000x UHS-II 128GB card in Slot 1 and a SanDisk Extreme (not Pro) V30 UHS-I 128GB card in slot 2 on my A7Riii.

SanDisk Extreme (not Pro) V30 UHS-I 128GB on the left (approx AUD$90) and the Lexar 1000x UHS-II 128GB on the right (approx AUD$140).

The Lexar in my case is definitely faster than the SanDisk card, though I have not run any formal benchmarks - you can just see it in general read/write operations on a PC.

Doing the completely unscientific filling the buffer test on my A7Riii, and starting the stopwatch at the first slow snap (approximately 80 images, RAW+JPEG, full res, X.FINE mode) and then stop the clock when the last image has finished writing:

  • For JPEG on Lexar Slot 2, RAW on SanDisk Slot 1: 54.47 seconds
  • For RAW on Lexar Slot 2, JPEG on SanDisk Slot 1: 49.42 seconds
  • For JPEG on Lexar Slot 1, RAW on SanDisk Slot 2: 54.56 seconds
  • For RAW on Lexar Slot 1, JPEG on SanDisk Slot 2: 47.77 seconds

This doesn't seem right. Shouldn't 3 and 4 in your list take the minimum time since the faster card is in the faster slot? Did you mix up your times? Shouldn't 3 and 4 be faster than 1 and 2?

So the largest difference was just under 7 seconds. The Lexar shows that is also performs better than the SanDisk even on the UHS-I-only slot 2.

Images appear to be written sequentially by the A7Riii, so one card will not finish writing all images before the other. They will always ultimately finish together.

Repeating the fill-the-buffer test with RAW + JPEG being written to the ONE card in Slot 1 only, shows:

  • Lexar: 62.47 seconds
  • SanDisk: 86.05 seconds

Most online reviews seem to pit the Lexar 1000x writing speed at between 75 and 85MB/s, and the SanDisk Extreme V30 (not Pro) writing speed at between 62 and 64MB/s.

This shows that the camera is very much as fast as the slowest card in either slot when writing to both at the same time. Since both these cards can be had relatively cheap, in my books it would not be worth buying a card that can only do 30MB/s when the UHS-I slot on the camera can do at least twice that speed. That said, if you only ever take single shots and never burst shots, then it probably won't affect you at all anyway.

See my question above?

Steve

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vett93
vett93 Senior Member • Posts: 4,292
Re: A7R3 - Best Choice SD Card for Slot 2???

Jekabs wrote:

Personally, I decided against the fastest UHS-II cards in my A7rIII. They are still relatively expensive and would be of no benefit for what I shoot. The buffer is large enough for anything I can think I would use it for and camera is mostly operational while clearing the buffer, unlike A7rII. Also, it is pointless to have fast card if you will be mostly writing to both slots for backup, because the second slot will be the bottleneck anyway.

This is what I thought as well. When I use 2 cards, I plan to use the 2nd slot for RAW backup. So I am not sure it would help even if I get a faster card for slot 1.

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Jeff Sereno
Jeff Sereno Regular Member • Posts: 151
Re: A7R3 - Best Choice SD Card for Slot 2???

Steve W wrote:

This doesn't seem right. Shouldn't 3 and 4 in your list take the minimum time since the faster card is in the faster slot? Did you mix up your times? Shouldn't 3 and 4 be faster than 1 and 2?

No, because even at UHS-I limits, the Lexar is still a faster card than the SanDisk.

You CAN buy 100MB/s+ cards that are only UHS-I spec.

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AW9nineteen Forum Member • Posts: 80
Re: A7R3 - Best Choice SD Card for Slot 2???

Bummer. I just ordered a Sony G UHS-II to use for faster writing. Initially I wanted to shoot RAW in one slot and JPEG in another. This is making is seem like if you want to do that then you should just save the money and get two UHS-I, am I correct? I like not shooting RAW in slot 2 because if I ever wanted to just quickly transfer some images to my iPhone or iPad I can do so without touching it up.

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Jeff Sereno
Jeff Sereno Regular Member • Posts: 151
Re: A7R3 - Best Choice SD Card for Slot 2???

It really depends on how you shoot. The only reasons you would want a lightning fast card for is probably just:

  • Doing regular burst shoots, emptying the buffer asap
  • Dumping over a thousand photos or hours of videos from your most recent shoot to your computer
  • Recording high bit rate, high frame rate video

If you shoot one shot here and there every few seconds and never more than a hundred or so photos at your heaviest, then a slower and cheaper card may suffice.

But don't skimp out on quality if going for something cheaper. You want at least one spare card handy for the inevitable day that your primary card fails, or at the very least use the second card to rotate the card wear.

 Jeff Sereno's gear list:Jeff Sereno's gear list
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Steve W Veteran Member • Posts: 4,158
Re: A7R3 - Best Choice SD Card for Slot 2???

Jeff Sereno wrote:

Steve W wrote:

This doesn't seem right. Shouldn't 3 and 4 in your list take the minimum time since the faster card is in the faster slot? Did you mix up your times? Shouldn't 3 and 4 be faster than 1 and 2?

No, because even at UHS-I limits, the Lexar is still a faster card than the SanDisk.

You CAN buy 100MB/s+ cards that are only UHS-I spec.

So what UHS-1 cards do > 100MB/s ?

Steve W

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Abrak Veteran Member • Posts: 4,130
Re: A7R3 - Best Choice SD Card for Slot 2???

I did some testing too.... (with A7riii)

Bottom line....

You only get write speeds 'significantly' above 100MB/s (about 150 MB/s) shooting 'uncompressed' RAW to slot 1 with the 300 MB/s cards.

Essentially the 'compression' slows down the write times quite a bit, so you dont lose much in terms of speed with the 95MB/s Scandisk cards that write at about 80 MB/s to slot 1.

Unless you are shooting 'uncompressed' RAW I dont really think that the superfast SD cards are worth the expense.

AW9nineteen Forum Member • Posts: 80
Re: A7R3 - Best Choice SD Card for Slot 2???

Jeff Sereno wrote:

It really depends on how you shoot. The only reasons you would want a lightning fast card for is probably just:

  • Doing regular burst shoots, emptying the buffer asap
  • Dumping over a thousand photos or hours of videos from your most recent shoot to your computer
  • Recording high bit rate, high frame rate video

If you shoot one shot here and there every few seconds and never more than a hundred or so photos at your heaviest, then a slower and cheaper card may suffice.

But don't skimp out on quality if going for something cheaper. You want at least one spare card handy for the inevitable day that your primary card fails, or at the very least use the second card to rotate the card wear.

Thanks, that definitely makes sense. The only thing I know for a fact I will be doing is recording High bit rate, high frame rate video. With the way tech and displays are going, I want to record the best possible video. Birthday parties, some parts of sporting events, etc I will want the best I can get out of the camera. As I am writing this, it makes me think I should have gone 128gb and not the 64gb.

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Abrak Veteran Member • Posts: 4,130
Re: A7R3 - Best Choice SD Card for Slot 2???
1

AW9nineteen wrote:

Jeff Sereno wrote:

It really depends on how you shoot. The only reasons you would want a lightning fast card for is probably just:

  • Doing regular burst shoots, emptying the buffer asap
  • Dumping over a thousand photos or hours of videos from your most recent shoot to your computer
  • Recording high bit rate, high frame rate video

If you shoot one shot here and there every few seconds and never more than a hundred or so photos at your heaviest, then a slower and cheaper card may suffice.

But don't skimp out on quality if going for something cheaper. You want at least one spare card handy for the inevitable day that your primary card fails, or at the very least use the second card to rotate the card wear.

Thanks, that definitely makes sense. The only thing I know for a fact I will be doing is recording High bit rate, high frame rate video. With the way tech and displays are going, I want to record the best possible video. Birthday parties, some parts of sporting events, etc I will want the best I can get out of the camera. As I am writing this, it makes me think I should have gone 128gb and not the 64gb.

The maximum 'bit' rate that the A7riii shoots video at is 100mbit/s which is roughly equivalent to 12MB/s which isnt very fast. I record video in slot 2.

teddoman
teddoman Senior Member • Posts: 2,483
Re: A7R3 - Best Choice SD Card for Slot 2???

Steve W wrote:

Jeff Sereno wrote:

Steve W wrote:

This doesn't seem right. Shouldn't 3 and 4 in your list take the minimum time since the faster card is in the faster slot? Did you mix up your times? Shouldn't 3 and 4 be faster than 1 and 2?

No, because even at UHS-I limits, the Lexar is still a faster card than the SanDisk.

You CAN buy 100MB/s+ cards that are only UHS-I spec.

So what UHS-1 cards do > 100MB/s ?

How's that possible? Isn't 100 MB/s the limit for UHS-I?

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Ted
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Jeff Sereno
Jeff Sereno Regular Member • Posts: 151
Re: A7R3 - Best Choice SD Card for Slot 2???

Steve W wrote:

So what UHS-1 cards do > 100MB/s ?

Dunno, haven't looked.

The UHS-I v3.01 spec supports up to 104MB/s, so it's possible.

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OP oliveview Forum Member • Posts: 55
Re: A7R3 - Best Choice SD Card for Slot 2???

Abrak wrote:

AW9nineteen wrote:

Jeff Sereno wrote:

It really depends on how you shoot. The only reasons you would want a lightning fast card for is probably just:

  • Doing regular burst shoots, emptying the buffer asap
  • Dumping over a thousand photos or hours of videos from your most recent shoot to your computer
  • Recording high bit rate, high frame rate video

If you shoot one shot here and there every few seconds and never more than a hundred or so photos at your heaviest, then a slower and cheaper card may suffice.

But don't skimp out on quality if going for something cheaper. You want at least one spare card handy for the inevitable day that your primary card fails, or at the very least use the second card to rotate the card wear.

Thanks, that definitely makes sense. The only thing I know for a fact I will be doing is recording High bit rate, high frame rate video. With the way tech and displays are going, I want to record the best possible video. Birthday parties, some parts of sporting events, etc I will want the best I can get out of the camera. As I am writing this, it makes me think I should have gone 128gb and not the 64gb.

The maximum 'bit' rate that the A7riii shoots video at is 100mbit/s which is roughly equivalent to 12MB/s which isnt very fast. I record video in slot 2.

Sony hoses in this regard, I feel. With my older Nikon gear, I always had the fully discrete choice over every format / card location. So, I always recorded RAW to one card, then redundant JPEGs and all movies to the second. However, with the A7R3, now that I have selected RAW to slot 1 and JPEG to slot 2, it forces me to record movies to slot 1 as well.

But perhaps, there are more card write speed requirements for HQ video, which still necessitate that full speed from slot 1?

terryreid
terryreid Senior Member • Posts: 1,740
Re: A7R3 - Best Choice SD Card for Slot 2???

oliveview wrote:

So, I bought two top of the line UHS-2 300/300 Sony SD cards for the new camera. Both, 128gig. However, knowing that slot 2 doesn't exploit those speeds, I realize that I'm entirely wasting one of those cards in that slot. I've looked through the instruction manual, and it only mentions UHS-I for slot two, but with no mention of actual max read/write speeds.

Does anyone know what slot 2 maxes out at?

I'd like to just buy a third, cheaper SD card for that purpose, and therefore use the two ultra-fast UHS-2 cards in slot 1. But how low can I go? 30megs/sec?

Thanks!

I do not use slot 2 and wish I could find a way to disable it on the A9 too.

I am not certain but I believe the slower slot 2 has to have some affect on the write speed when using continous Hi, it certainly cannot help.

I have taken over 500,000 photos and never had a card fail and if it every happens it is just some pictures I will live. I have a lot bigger problems than that occur often in my companies. It is hardly a concern of mine. For paid shooters perhaps but not for me.

I have been stopped in my tracks twice when card 2 filled up on my A9 and was as done for the day. And no I do not always carry extra SD cards in my pocket.

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