Question Why is my MicroSD card very slow ?

[procat1234]

I have a Sandisk MicroSD card (red-gray). The advertized read speed is up to 140MB/s, but i only got 83MB/s. Is it because of the silicon lottery? Also, when I tried copying files from my card to my laptop, it starts copying at around 60MB/s for a few seconds before gradually slowing down to only around 8MB/s. I tested my card and it should have 83MB/s read and 30MB/s write.

Thank you for your help .

 

[kanewolf]

I have a Sandisk MicroSD card (red-gray). The advertized read speed is up to 140MB/s, but i only got 83MB/s. Is it because of the silicon lottery? Also, when I tried copying files from my card to my laptop, it starts copying at around 60MB/s for a few seconds before gradually slowing down to only around 8MB/s. I tested my card and it should have 83MB/s read and 30MB/s write.

Thank you for your help .

What type storage are you copying onto in the laptop ? NVMe SSD? SATA SSD? SATA HDD ?

 

[USAFRet]

I have a Sandisk MicroSD card (red-gray). The advertized read speed is up to 140MB/s, but i only got 83MB/s. Is it because of the silicon lottery? Also, when I tried copying files from my card to my laptop, it starts copying at around 60MB/s for a few seconds before gradually slowing down to only around 8MB/s. I tested my card and it should have 83MB/s read and 30MB/s write.

Thank you for your help .

Many possible reasons.

Data transfer is only as fast as the slowest device in the chain.
What type of adapter is the micro plugged in to?
Composition of the data? Many small files transfer slower than a single large file.

Remember, that advertised speed is a theoretical, in perfect lab conditions.

 

[Misgar]

Are you using a high quality UHS I or UHS II card reader? Cheap readers can give mediocre results.

I can recommend the Kingston FCR-HS3 and FCR-HS4.
https://www.cameramemoryspeed.com/reviews/card-readers/kingston-memory-card-reader-fcr-hs4/

I've had read speeds in excess of 180MB/s from a UHS II SD card in the FCR-HS3. It would have been around 220MB/s if I'd used the more modern FCR-HS4.

The FCR range is handy for reading CF cards from my DSLRs, plus microSD from my GoPro.

Alternatively, you could try a Lexar card reader.

 

[procat1234]

What type storage are you copying onto in the laptop ? NVMe SSD? SATA SSD? SATA HDD ?

NVMe SSD

 

[USAFRet]

NVMe SSD

What make/model
Some are better than others.

 

[procat1234]

Many possible reasons.

Data transfer is only as fast as the slowest device in the chain.
What type of adapter is the micro plugged in to?
Composition of the data? Many small files transfer slower than a single large file.

Remember, that advertised speed is a theoretical, in perfect lab conditions.

It's plugged into a USB -A 3.0 port. I put a lot of small files and some large ones that amounted to about 20GB.

 

[procat1234]

What make/model
Some are better than others.

I used my laptop, task manager just said INTEL SSDPEKNW512G8L

 

[procat1234]

Are you using a high quality UHS I or UHS II card reader? Cheap readers can give mediocre results.

I can recommend the Kingston FCR-HS3 and FCR-HS4.
https://www.cameramemoryspeed.com/reviews/card-readers/kingston-memory-card-reader-fcr-hs4/

I've had read speeds in excess of 180MB/s from a UHS II SD card in the FCR-HS3. It would have been around 220MB/s if I'd used the more modern FCR-HS4.

The FCR range is handy for reading CF cards from my DSLRs, plus microSD from my GoPro.

Alternatively, you could try a Lexar card reader.

I just used a cheap Micro SD Card reader from a brand called "Orico". It said it could support up to 5Gbps transfer speed?

 

[USAFRet]

It's plugged into a USB -A 3.0 port. I put a lot of small files and some large ones that amounted to about 20GB.

USB-A, and lots of small files...that WILL transfer slowly.

 

[Misgar]

It said it could support up to 5Gbps transfer speed?

5Gbps is the theoretical maximum speed of good old fashioned USB3, before they started to get clever and add go-faster stripes. Just because Orico quote 5Gbps doesn't mean your card reader will be able to achieve this speed in the real world.

I've been using Kingston FCR-HS3 readers for at least six years and they too work on 5Gbps USB3, with a standard Type A plug on the end of a short plug-in cable.

Despite this USB Type A 5Gbps "limitation" I get very good speeds transferring JPG files (10 to 15MB) from full size SD cards and RAW image files (35 to 55MB) from Compact Flash cards.

Even better are transfers of GoPro 4K video files (1GB to 12GB) from microSD cards in the same FCR-HS3 readers connected to USB Type A inputs on my laptops.

If I get the time over the New Year, I'll run a few tests on microSD, SD and CF cards and report back with transfer rates. A lot depends on the speed of the card too (obviously). Cheaper slower cards cannot be expected to keep up with faster more expensive cards, regardless of the reader used.

I tried to log in to the Orico shop, but all I got was a "shop closed" message and "please try again in a few days". This does not inspire me with much confidence.

If your small files are really small (less than 1MB) you won't see fast transfers. Big files (over 50MB) should transfer faster. This applies pretty much regardless of what media/drives you're transferring from/to. Small files slow things down.

I zip folders full of small fles (under 10MB per file) before saving to LTO tape, because my tape drive requires a constant data rate of 80MB/s. Anything less than a continuous 80MB/s and the tape drive starts "shoe shining".

I suspect your speed limitations may be due to a less than ideal card reader. See if you can get a (potentially obsolete) Kingston FCR-HS3 (on eBay?) or the newer FCR-HS4.

Alternatively try one of the other Kingston, Sandisk or Lexar readers. Expect to pay $25+ (probably more) for a good reader.
https://www.digitalcameraworld.com/buying-guides/the-best-memory-card-readers

You can ignore the CF Express readers. These provide truly phenomenal transfer rates up to a theoretical 4,000MB/s, which puts even UHS III SD card 600MB/s to shame.
https://www.fixationuk.com/cfexpress-cards-explained/

 

[Moonstick2]

It's plugged into a USB -A 3.0 port. I put a lot of small files and some large ones that amounted to about 20GB.

Look at it a bit like car speeds. You buy a car with 130 mph top speed and drive it on a long journey with a variety of roads and traffic. You wouldn't expect to reach 130 mph average.