This experiment compares the speed of Sandisk Ultra microSD 32GB vs. Sandisk Extreme microSD 32GB. Sandisk Ultra promises “up to 48 MB/s” speed and Sandisk Extreme promises “up to 60 MB/s”. Both cards are rated as Class 10 and UHS-I enabled. Sandisk Extreme is more expensive than Sandisk Ultra, so let’s see if the price difference is worth the performance difference.
For this test, I use a Mac mini with built-in USB 3.0 ports. The memory cards are accessed through a USB 3.0 memory card reader (Transcend RDF5). I prepared three sets of data to be written to, and read from the micro SD cards:
- Data A is 1 large file. The size is 4.25 GB.
- Data B is a set of 12 medium files. The total size is 5.81 GB.
- Data C is a set of 45,976 small files. The total size is 5.47 GB.
Testing process is simple. First I formatted each memory card using ExFAT so at the beginning of the test, they are empty. The formatting uses standard ExFAT from Windows with all default settings. To measure WRITE speed, I copied each set of data into each memory card and timed the process. To measure READ speed, I copied back those sets of data back into my computer and timed the process. To perform the file transfers, I use a tool named ChronoSync 4.6.2. This is a backup app for Mac, but I have good experience using it as file copier because it performs generally faster than using the standard Finder.
| Operation | Data | Sandisk Ultra |
Sandisk Extreme |
Samsung Evo |
| WRITE | A | 5 mins 20 secs avg speed 13.60 MB/s |
1 mins 23 secs avg speed 52.43 MB/s |
3 mins 24 secs avg speed 21.33 MB/s |
| WRITE | B | 8 mins 15 secs avg speed 12.02 MB/s |
2 mins 3 secs avg speed 48.37 MB/s |
4 mins 20 secs avg speed 22.88 MB/s |
| WRITE | C | 42 mins 13 secs avg speed 2.21 MB/s |
19 mins 0 sec avg speed 4.91 MB/s |
25 mins 15 secs avg speed 3.70 MB/s |
| READ | A | 1 mins 37 secs avg speed 44.87 MB/s |
1 min 37 secs avg speed 44.87 MB/s |
1 min 57 secs avg speed 37.20 MB/s |
| READ | B | 2 mins 27 secs avg speed 40.47 MB/s |
2 mins 26 secs avg speed 40.75 MB/s |
2 mins 34 secs avg speed 38.63 MB/s |
| READ | C | 15 mins 49 secs avg speed 5.90 MB/s |
5 mins 58 secs avg speed 16.62 MB/s |
7 mins 16 secs avg speed 12.85 MB/s |
As expected, Sandisk Extreme wins all tests. To be fair, Samsung Evo is positioned as direct competitor to Sandisk Ultra. Samsung still has Samsung Evo Plus and Pro with higher speed specifications, so this experiment does not show that Samsung memory cards are slower than Sandisk. We need to compare products from the same level to actually compare them.
Usually, copying a lot of small files take significantly longer time because there are additional process that must be completed for each file. However, this experiment shows interesting results as READ A is actually slower than WRITE A and READ B is slower than WRITE B. I can only guess that this is caused by the writing speed of my Mac mini’s internal HDD. With transfer speed reaches a point higher than the writing speed of my HDD, the READ process (which basically read data from micro SD card and write them to my internal storage) got limited by the writing speed of my HDD. If I do this experiment using Macbook Pro with SSD, the results might be different.
Edit 27 Jun 2020: today I repeat this experiment for the Sandisk Ultra and Sandisk Extreme micro SD cards with my Mac mini using SSD, you can see the results here.
Great, thanks very much. I now know to buy both an Extreme and an Ultra – these will be most suited to the 2 devices I have. Its easy to over specify/speed. Buying direct from WD as same prices as Amazon :-)
Thanks for these useful figures.
I am using an Extreme SDcard to run my Raspberry
I confirm that the performances are much better than with another SDcard
Thank you for posting these results. You are on dot regarding the analysis. Helpful to compare and decide.
Still confused. Camera is suppose to be WIFI & HDMI ultra HD 4K video. Up to 64GB Micro Sd card.
Should I get the Sandisk Ultra red and gray it has a 10 in the U. Would it be better to get 2 32 cards in the evwnt something happens to one? Its all greek to me, just a little action camera for underwater and sports. Not a GP but cheaper type. I orderd the camera but waiting to figure out the card. Thanks for any help. Maybe I got it right.
So it appears that the difference is in the reading or writing to the computer or whatever you are transferring to, right? Does it make a different in terms of actually taking the pictures or videos?
Correct. Taking photos and videos (up to 1080p) only requires SD card speed class 10. You can see this from the icon of 10 number inside a circle on the memory card. Anything with a number inside a U-shaped icon means it’s even faster than “standard” class 10. Since this article compares Sandisk Ultra and Sandisk Extreme, and both of them have class 10 speed or higher, the speed difference will only matter when transferring files to a computer/tablet.
However, recording 4K videos (or higher) is a different story. It does require faster memory card. Also, opening View mode in camera does feel noticeably faster with faster memory card when we have thousands of photos and videos inside.
@Robert.have you ever seen any card go over class 10? If you say yes you’re lying
Card class is to provide standard of MINIMUM speed. When a card is class 10, it means the card should have minimum write speed of 10 MB/s, the card’s speed itself can be higher than that. The fastest write speed of an SD card is 273 MB/s (Sony SF-G U3 UHS-II)
Thank for the great sharing and the comparison result for Sandisk Ultra versus Extreme.
Thanks Buddy…. very valuable information
Excellent! Thank you. This answers the question I had and makes a choice much easier.
Thank you for running this test and posting your results. The was “Extremely” helpful to me. Sorry, I know that’s bad but I couldn’t help it.