Comparing Lexar Class 10 SDHC with Sandisk SDHC Class 10

[John 2]

Thought this might be of interest to others. Up to now I have using 16GB Sandisk Pro cards in my cameras rated at 95 GB/s. I recently treated my self to a 16GB Lexar Pro 1000x rated at 150MB/s. Out of curiosity I thought that I would just see what difference the faster card makes. I set my Fuji XT-1 up on fast repetitive mode, set the aperture to wide open for the target chosen which gave a shutter speed for both cards of 1/50 Sec @f2.8. These were the results:

Sandisk /Lexar
Card Speed 95MBps /150MBps
Available shots 472 /463
Time to slow 4 secs /3 secs
Shots fired 25 /22
Time to Write 24 secs /30 secs


Not a scientific test by any means but fairly controlled in terms of comparing like with like. My interpretation is that the card that purports to be 50% faster turns out to have less capacity (only just - can't get excited) and is slower to write with the result that the camera buffer fills up more quickly and you get less high speed shots before the process slows down to the write speed. Don't get me wrong, both cards do the job well but was it worth paying extra for the apparent increased speed of the Lexar? I think that this perhaps down to the "up to" tag in describing the performance as in "up to 150MB/s". Thought I would pass these results on.

[dem]

Where both cards formatted in camera just before the shoot?

It appears that you are shooting RAW+jpeg in continuous drive till the camera buffer is full. Is this correct?

[DanK]

The speed will be limited by the slowest part of the system. I don't know that camera, but it may be that the card speed is in excess of what the camera can write. I recently read some tests indicating that the fastest cards are a waste for many cameras, but I don't recall the link.

[John 2]

Dem, no I was just shooting RAW until the buffer filled up at which point the frame rate fell to what ever rate the card in question was accepting images.

Dan you are absolutely right but if the camera was a bottleneck, the speed at which images were written to the card would be the same for both cards. That clearly wasn't the case. The fact that the Sandisk could accept images at a higher rate meant that the buffer could process more images before it filled up (i.e. to put it crudely, before the input caught up with the output) - as the results seem to demonstrate.

[Manfred M]

John - I haven't found a lot of difference in write time, but I find that the read time can make a lot of difference; some of my fastest cards download at several times the speed of my slower ones.

[Shadowman]

Thought this might be of interest to others. Up to now I have using 16GB Sandisk Pro cards in my cameras rated at 95 GB/s. I recently treated my self to a 16GB Lexar Pro 1000x rated at 150MB/s. Out of curiosity I thought that I would just see what difference the faster card makes. I set my Fuji XT-1 up on fast repetitive mode, set the aperture to wide open for the target chosen which gave a shutter speed for both cards of 1/50 Sec @f2.8. These were the results:

Sandisk /Lexar
Card Speed 95MBps /150MBps
Available shots 472 /463
Time to slow 4 secs /3 secs
Shots fired 25 /22
Time to Write 24 secs /30 secs


Not a scientific test by any means but fairly controlled in terms of comparing like with like. My interpretation is that the card that purports to be 50% faster turns out to have less capacity (only just - can't get excited) and is slower to write with the result that the camera buffer fills up more quickly and you get less high speed shots before the process slows down to the write speed. Don't get me wrong, both cards do the job well but was it worth paying extra for the apparent increased speed of the Lexar? I think that this perhaps down to the "up to" tag in describing the performance as in "up to 150MB/s". Thought I would pass these results on.

I wonder if camera manufacturers do the same testing or do they just enter into service agreement with one or two manufacturers. I usually try to stick to the approved cards, but once in awhile I'll purchase a non-sanctioned card and just keep my fingers crossed.

[dem]

Assuming that each RAW file is about 30 MB, we've got the actual writing speeds as

30 * 25 / 24 = 31 MBps for SanDisk
30 * 22 / 30 = 22 MBps for Lexar

I suppose the speed all manufactures quote on their card is always the "read" speed as it is faster than the "write" speed and therefore better for marketing purposes. And then they come with obscure descriptions like "transfer rate" or "write/read speed up to" to further hide this fact. Lexar in particular seems to be very cagey about their write speed:

*Up to 150MB/s read transfer, write speeds lower. Speeds based on internal testing. Actual performance may vary.

While SanDisk actually quotes both speeds for every card they sell:

40 MBps write (10 MBps read)
60 MBps write (40 MBps read)
95 MBps write (90 MBps read)

I was about to buy a few more SD cards. Will stick with Sandisk for now. Thanks for the heads up, John.

[John 2]

John, Fuji have their own brand so not surprisingly, they don't have a recommended list.

Good thought Manfred. All I can find on the Lexar site is:"Up to 150MB/s read transfer, write speeds lower. Speeds based on internal testing. Actual performance may vary. x=150KB/s." I couldn't find out what "x" is.

Sandisk on the other hand quote: "Delivers up to 90MB/s**Up to 95 MB/sec (633X) read speed."

Like DEM, I think I will stick to Sandisk for the time being.

[Ken MT]

From Lexar web site

Capacities:
SDHC
16GB—Class 10, UHS-I (U1), 633x (up to 95MB/s read, 20MB/s write)
32GB—Class 10, UHS-I (U3), 633x (up to 95MB/s read, 45MB/s write)

says it all

[John 2]

Different Cards Ken but as you say, says it all.

[Manfred M]

John - My cards are exclusively a collection of Lexar and Sandisk, mostly lexar. Not being a burst shooter, the write rates don't impact me very much, but the read rate sure does (64GB cards across the board).

Both companies manufacturer their own cards, whereas most of the rest are made for them by other manufacturers (nicely said, the lowest bidder to meet the spec makes the cards). I've never had a card from either fail (i.e. have any kind of an error) and they both stand behind their product.

[John 2]

Manfred, ditto here. In fact I use a Lexar USB 3 card reader that is excellent. My comment wasn't so much a crit of the Lexar card so much as acknowledging that ken had found the probable reason for the result and comment on my failure to realise what I should have looked for i.e. the write speed. I do a bit of sport and wild life and use burst mode quite a lot for them and I should have known better.