Geekin' out on SD Card speeds! - Page 2

atomic · #11 May 10th, 2012, 02:28 AM

Okay, I got started in this today. I'll post preliminary results. I should have reread the procedure before I started as I misremembered and counted shots for 10 seconds after full buffer instead of timing 10 shots. I have the data (recorded the audio so I could be sure to get my count right), so I can redo the numbers later. It's late and I'm tired, so here is the rough data. I'll add pictures of each card for identification purposes later.

Each card was empty, formatted. Camera is E-PM1, set to manual focus, 1/4000 shutter speed. I started the count on the second post buffer shot and counted for 10 seconds. In most cases the pause between the buffer filling and first, and between first and second shots was longer than the rest, so I eliminated these from my results. Math assumes 8Mb per shot, as above.

Sandisk Extreme Pro 45 Mb/sec 16GB - 30 shots in 10 sec = 3.0 shots per second = 24 Mb/sec
Lexar Professional 133x 32GB - 29 shots in 10 sec = 2.9 shots per second = 23.2 Mb/sec
Transcend class 10 SDHC 16GB - 28 shots in 10 sec = 2.8 shots per second = 22.4 Mb/sec
PNY Professional class 10 20Mb/sec 16GB - 17 shots in 10 sec = 1.7 shots per second = 13.6 Mb/sec
PNY SDHC class 4 (old) 4GB - 16 shots in 10 sec = 1.6 shots per second = 12.8 Mb/sec
Patriot LX series class 10 8GB - 12 shots in 10 sec = 1.2 shots per second = 9.6 Mb/sec
Eye-fi SD card 2GB - 9 shots in 10 sec = 0.9 shots per second = 7.2 Mb/sec

One thing I noticed is that while with all the other cards I got a fairly steady shot rate once the buffer filled and the first shot recorded, the PNY 16GB class 10 card would shoot 3 or 4 quickly, then pause, then 3 or 4 more. I have no theory as to why.

Chrisnmn · #12 May 10th, 2012, 02:32 AM

Hey guys, when i was looking SD cards for my EPL2, i got into this review which is also really nice and ended up buying the Trascend Class 10 cards and they are just perfect!

Best memory card for Olympus E-PL2 | Daisuki Photo

heedpantsnow · #13 May 10th, 2012, 05:01 AM

Quote:

Originally Posted by jff1625

Hi,
I'm trying to guesstimate what kind of continuous shooting speed I could get on my E-PM1 after the buffer fills up, when using various SD Cards that I don't have. Hopefully this will help me to decide whether or not I want to get a faster card, and if so which one. I'm posting my research here in the hope that some kind or curious person or persons might like to confirm or correct some of my numbers if they happen to have the cards in question, or their equivalents. If this info proves helpful to someone, so much the better. Also I find this kind of thing fun. I must be nuts

The resources I'm using for this are:
1) my own testing with my E-PM1 and Sandisk 8GB Class 4 card
2) dpreviews review of continuous shooting performance of the E-M5 an E-PM1
3) Giulio Scorios test on his blog of his E-M5 including the card I have and some that I'm interested in. Giulio didn't record his "buffer-full" shot rate but I think I can extrapolate it from his results by referring to and comparing with my and dpreviews numbers.
4) amazon.co.uk for pricing

I'm making a few assumptions, namely:
- E-M5 jpegs are 11MB
- E-M5 buffer takes 16 jpegs
- E-PM1 jpegs are 8MB
- E-PM1 buffer takes 9 jpegs

Same 4 cards as on Giulio's test minus the eye-fi.
Remember the main thing I'm looking for is a shots per second speed when the buffer is already full.
Numbers and maths follow from here, lets dive in!

Sandisk 8GB Class 4
My test:
10 shots in 15.99sec -> 0.63 shots/sec when buffer full on E-PM1
14.37 sec to clear buffer
Giulio:
Buffer cleared just under 56 seconds.
11MB/shot * 16 shots = 176MB / 56sec = 3.1MB/sec = 0.3 shot/sec on OMD, or 0.5 on PM1

So for this card our numbers are much the same, when allowing for timing inaccuracies and rounding errors and whatnot.
Price per speed for this works out at £4.48 / 3.1MB/sec = 1.40£/MB/sec

Sandisk Extreme 4GB 30MB/s
Giulio:
Buffer cleared just under 13 seconds.
11MB/shot * 16 shots = 176MB / 13sec = 13.5MB/sec = 1.2 shots/sec on OMD, or 1.6 on PM1
DPReview:
8MB/shot @ 1.6 shots/sec = 12.8MB/s = 1.1 shots/sec on OMD, or 1.6 on PM1

Again the two sources match up pretty well. Interestingly the buffer-full-shooting write speed is considerably less that the speed written on the card label, but greater that the 'class rating' speed (which is 10 for this card)
Price per speed £8.79 / 13MB/s = 0.67£/MB/sec

Sandisk Extreme Pro 16GB 45MB/s
Giulio:
Buffer cleared just under 17 seconds.
11MB/shot * 16 shots = 176MB / 17sec = 10.3MB/sec = 0.9 shots/sec on OMD, or 1.2 on PM1
I don't have other data to compare for this card so I'll have to take Giulios word for it, but he looks like a trustworthy bloke. As G noted, this card tested a bit slower than the smaller but slower-rated 4GB 30MB/s card.
Price per speed £14.40 / 10.3MB/s = 1.40£/MB/sec

Sandisk Extreme Pro 16GB 95MB/s
Giulio:
Buffer cleared just under 10 seconds.
11MB/shot * 16 shots = 176MB / 10sec = 17MB/sec = 1.6 shots/sec on OMD, or 2.1 on PM1
Price per speed £32.30 / 17MB/s = 1.90£/MB/sec

Sandisk Extreme Pro 64GB 95MB/s
DPReview didn't post numbers for Large/SFine jpeg/11MB, so from the numbers they did post I guesstimate the E-M5 buffer full rate at 2.2shots/sec so:
11MB/shot * 16 shots = 176MB / 6sec = 29MB/sec = 2.4 shots/sec on OMD, or 3.6 on PM1

Price per speed £128.87 / 29MB/s = 4.44£/MB/sec

It looks like DPRs 64GB card is faster than Giulios 16GB one.
Also DPRs card can apparently write at pretty close to the PM1s continuous shooting speed of 5fps!

The price / performance sweet spot among these is owned by the Sandisk Extreme 4GB 30MB/s card, which for £8.79 should give a buffer-full shooting rate of 1.2 shots/sec on OMD, or 1.6shots/sec on PM1. Above this the law of diminishing returns starts to kick in.

What do you think? Is this kind of thing helpful? Does anyone have any corrections or extra info to add? Did anyone read all the way down this far?

cheers,

-J

Thanks for the information! IMHO one suggestion to make it even more useful (and maybe you already thought of this): could you modify your cost per speed to be cost per speed per GB? It seems like it would be more 'fair'.

jff1625 · #14 May 10th, 2012, 03:59 PM

Quote:

Originally Posted by atomic

Sandisk Extreme Pro 45 Mb/sec 16GB - 30 shots in 10 sec = 3.0 shots per second = 24 Mb/sec
Lexar Professional 133x 32GB - 29 shots in 10 sec = 2.9 shots per second = 23.2 Mb/sec
Transcend class 10 SDHC 16GB - 28 shots in 10 sec = 2.8 shots per second = 22.4 Mb/sec
PNY Professional class 10 20Mb/sec 16GB - 17 shots in 10 sec = 1.7 shots per second = 13.6 Mb/sec
PNY SDHC class 4 (old) 4GB - 16 shots in 10 sec = 1.6 shots per second = 12.8 Mb/sec
Patriot LX series class 10 8GB - 12 shots in 10 sec = 1.2 shots per second = 9.6 Mb/sec
Eye-fi SD card 2GB - 9 shots in 10 sec = 0.9 shots per second = 7.2 Mb/sec

One thing I noticed is that while with all the other cards I got a fairly steady shot rate once the buffer filled and the first shot recorded, the PNY 16GB class 10 card would shoot 3 or 4 quickly, then pause, then 3 or 4 more. I have no theory as to why.

Wow, great results Atomic! Your real cards are faster than my imaginary ones

I would guess that your PNY card has a slow 'random' read/write rate (try saying that 5 times quickly!) So it kinda loses the plot when trying to figure out where to start writing the next file.
I don't think the exact procedure matters too much as long as you're getting a buffer-full-shots-per-second figure and the speed is fairly consistent.

Quote:

Originally Posted by heedpantsnow

Thanks for the information! IMHO one suggestion to make it even more useful (and maybe you already thought of this): could you modify your cost per speed to be cost per speed per GB? It seems like it would be more 'fair'.

yeah, the cost per speed figure was just a bit of fun - all the cards bar one are under £20, so it hardly seems worthwhile unless you;re comparing the extreme high-end cards like that 64GB UHS-1 beast.

-J

jff1625 · #15 May 10th, 2012, 04:29 PM

Quote:

Originally Posted by Chrisnmn

Hey guys, when i was looking SD cards for my EPL2, i got into this review which is also really nice and ended up buying the Trascend Class 10 cards and they are just perfect!

Best memory card for Olympus E-PL2 | Daisuki Photo

Thanks Kiwi-Chris. Mr DaiSuki doesn't seem to say exactly what it was he was testing. I have to assume he just clicked the button once and waited till the 'card' light stopped flashing. It's not the same thing as buffer-full write speed but it should be reasonably comparable. His result for the "16GB Transcend class 10" and Atomic's, earlier in this thread, are roughly the same after adjusting for differences in file size, even tho the card capacities are different.
His relatively "meh" results for the UHS-1 cards seem to be explained by the specs for the E-PL2 not listing UHS-1 among its many talents.

Can anybody find a coherent way to explain or predict the difference in speed seen between two cards of different capacities but are otherwise identical? I've been told by various people that smaller cards are faster than bigger, and that bigger cards are faster than smaller. At least one of those opinions must be wrong! I suspect it's just random, and a side-effect of the "binning" process where are faster part might be badged as a slower one just to fill a gap in the market.

-J

jnewell · #16 June 30th, 2012, 08:03 PM

Based on the results in the first post and Giulio's blog, I bought a couple of Extreme Pro 95MB/s cards and tested them against my Extreme 45MB/s cards (both 16GB). I did a little different test routine (shoot continuous low till buffer fills, time to clear) so I got more pics off before the buffer filled, but a little to my surprise the number of pics to fill the buffer was actually either the same or only one greater with the 95MB/s card (due to greater read/write speeds) and the time to clear the buffer was only slightly faster with the 95MB/s card. I expected a greater difference...will be re-testing.

jff1625 · #17 September 12th, 2012, 02:43 AM

Hi All,
I finally bought my own Sandisk Extreme 8GB 95MB/s UHS-1 card. Test results added to the first post. It came out a little faster than the Sandisk 16GB 45MB/s and a little slower than the Sandisk 16GB 95MB/s. 1.8 shots/sec with buffer full on E-PM1.
I also tested in RAW mode with 11.1MB ORF files, and it wrote about 150MB worth of them in ten sec = 1.3 RAW shots/sec, so it seems the card writes faster with bigger files, altho not so much faster than you get a higher shots per second count.

Papayoyo · #18 November 2nd, 2012, 06:57 AM

Just received a Transcend 32GB class 10 and pretty disappointed by its 12.5 MB/s write benchmark, which is not even fast enough for the 13 MB/s needed for HD video on my E-PM1. Wondering why it's performing at half the speed of Atomic's 16GB Transcend. Should've gone for the Sandisk Extreme for £5 more. :(

kinlau · #19 November 2nd, 2012, 07:45 AM

Quote:

Originally Posted by Papayoyo

Just received a Transcend 32GB class 10 and pretty disappointed by its 12.5 MB/s write benchmark, which is not even fast enough for the 13 MB/s needed for HD video on my E-PM1. Wondering why it's performing at half the speed of Atomic's 16GB Transcend. Should've gone for the Sandisk Extreme for £5 more. :(

13Mb/s, not MB/s, note the lowercase vs uppercase, 13Mb/s is only 1.6MB/s. HD video typically only needs class 4 or 6, not even class 10.

Papayoyo · #20 November 2nd, 2012, 08:34 AM

Ah that's a relief. Haven't had a chance to try it out yet as expecting the camera tomorrow. Will update with in-camera performance.