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Hi Everyone, Is there a way to test a fake SD Card on MacBook Pro ?
- Thread starter Alpal0301
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If it‘s a ”fake” card why would you bother testing it? if you already know it’s fake seems like you have your test results already. What do you mean when you say “fake”?
Sorry maybe I should have put I want to test whether it’s fake or not. Fake means not original. ie it’s supposed to be a Samsung SD Card. I want to test whether it is or not. Thanks for your reply.
Run a BlackMagic Speed test on it. It'll give you a readout of how fast it performs for read and write operations, but there's one caveat. It can only test as fast as your SD Card slot performs. An SDXC II card isn't going to be able to run at full speed unless you're using an external SDXC II card reader.
Fake = Counterfeit
What you’re really asking is “can I test that the card is running to its advertised specs.“ ruslan120’s method would do exactly that.
The big name manufacturers buy their chips in bulk from various suppliers. As long as those chips run to the manufacturers specs there’s no problem. Occasionally a bad chip slips through their quality control. It happens. Take the slow card back where you bought it. They should replace it no questions asked as this type of thing is not unheard of.
What you’re really asking is “can I test that the card is running to its advertised specs.“ ruslan120’s method would do exactly that.
The big name manufacturers buy their chips in bulk from various suppliers. As long as those chips run to the manufacturers specs there’s no problem. Occasionally a bad chip slips through their quality control. It happens. Take the slow card back where you bought it. They should replace it no questions asked as this type of thing is not unheard of.
+ my understanding of fake cards is many come from China, and say they’re advertised as 256GB, some people will actually sell you a 32GB card and flash it to report 256GB. They overwrite data cyclically if you write more than 32GB, and by the time most people notice the refund window expires.
Except for the FinalCut tip, a very stupid set of answers. I ended up here trying to find a way to check capacity and speed of a couple of 128GB microSD cards I bought. Blackmagic's DST is not the answer, because a fake microSD usually doesn't test capacity. Even copying files won't show all problems... the Final Cut one would work though.
There is not a great solution for Mac beyond manually creating a file the same size of the SD card, moving it to the SD card, and then verifying the files copied over and are readable. I use H2TestW, but this is a Windows legacy program. (Effectively, this program writes data to fill up the entire drive and then attempts to read that data back. If it is unsuccessful in reading this data, it is an indication that you may have a defective and/or a fraudulent media device--combined with a speed test that shows vastly slower speeds than advertised by the maker, this is even more suggestive of an issue.)
There are tons of fake cards out there and some even come from reputable and authorized retailers (my guess is people buy them, take the real one, substitute it with a fake one (which is a forgery even down to the outer packaging), and return it. The retailer, not knowing the difference, then (unknowingly) sells the (fake) card to someone else. IMHO, it is definitely worth using one of these programs to verify EVERY SD card/flash drive you buy, no matter where you buy it from. These fake cards sometimes say a certain size on the packaging but actually are much smaller...without this sort of testing, you only know this when you go to retrieve the data and it isn't there as it simply overwrites itself.
A speed test can also potentially signal an issue. Do note, however, that many of the cheaper SD cards will advertise only read speed and write speeds will be drastically slower--with these cards that might vaguely advertise 100 MB/s, you might see 100 MB/s read speeds and less than 10 MB/s write speeds and this is not necessarily unusual. That doesn't necessarily indicate an issue. However, if you have a higher end SD card (say like one of the Samsung or Lexar models that are advertised at close to 100 MB/s read speeds and write speeds), it is only reading and writing at say 2.5 MB/s, and you are confident your SD card reader/system is not the bottleneck, that's a red flag!
There are tons of fake cards out there and some even come from reputable and authorized retailers (my guess is people buy them, take the real one, substitute it with a fake one (which is a forgery even down to the outer packaging), and return it. The retailer, not knowing the difference, then (unknowingly) sells the (fake) card to someone else. IMHO, it is definitely worth using one of these programs to verify EVERY SD card/flash drive you buy, no matter where you buy it from. These fake cards sometimes say a certain size on the packaging but actually are much smaller...without this sort of testing, you only know this when you go to retrieve the data and it isn't there as it simply overwrites itself.
A speed test can also potentially signal an issue. Do note, however, that many of the cheaper SD cards will advertise only read speed and write speeds will be drastically slower--with these cards that might vaguely advertise 100 MB/s, you might see 100 MB/s read speeds and less than 10 MB/s write speeds and this is not necessarily unusual. That doesn't necessarily indicate an issue. However, if you have a higher end SD card (say like one of the Samsung or Lexar models that are advertised at close to 100 MB/s read speeds and write speeds), it is only reading and writing at say 2.5 MB/s, and you are confident your SD card reader/system is not the bottleneck, that's a red flag!
I found a Mac/Linux app that does the trick: f3read and f3write. It can be downloaded through Homebrew with a simple 'brew install f3'. The procedure basically is something like 'f3write /Volumes/your_sdcard_label'. It will write a bunch of files until it fulfill your card. At the end it will show an average write speed. Then you run 'f3read /Volumes/your_sdcard_label'... it will read the written files and show an average read speed at the end. Pretty simple and free.
SDSpeed
Software to verify the integrity of your photography flash SD card or USB device.
App Store or
Software to verify the integrity of your photography flash SD card or USB device.
App Store or
sdspeed check SD card photo
sdspeed - check speed and integrity of your photography SD card sdspeed is the only product that measure the read and write rate and testing every bit of your SD memory card you can trust with no "conflict of interest". sdspeed software to verify the integrity of a flash SD Card. Easy to use...
apps.apple.com
Good for people who are afraid of using Terminal, but f3write and f3read (f3 package on Homebrew) do the trick for free.SDSpeed
Software to verify the integrity of your photography flash SD card or USB device.
App Store or
sdspeed check SD card photo
sdspeed - check speed and integrity of your photography SD card sdspeed is the only product that measure the read and write rate and testing every bit of your SD memory card you can trust with no "conflict of interest". sdspeed software to verify the integrity of a flash SD Card. Easy to use...apps.apple.com
You can find a GUI for macos port of f3 package at https://github.com/vrunkel/F3XSwift
The downloadable version of F3XSwift to test SD cards to see if they are faked is here: https://github.com/vrunkel/F3XSwift/releases/tag/v1.0.3. Same as above but a regular ol' application file. Works fine. Be careful; don't have files on the card when you test it. Given the increase in prices in cards I expect we'll be seeing more fakes.
This is the best answer — super simple, instructions are here: https://fight-flash-fraud.readthedocs.io/en/latest/usage.html#how-to-use-f3write-and-f3read