microSD card

[vinceASPECT]

Hello there Foum,

sorry to bother the forum but i was just wondering something about Laptops  (generally)

my laptop here has TWO hidden slots.........one is for a MicroSD card and the other is for a SIM card.

it's clear from the BIOS that the machine will boot off a microSD card.
So i expect that the machine
wil also just SEE the microSD card as an internal DRIVE right?   (say 32 gigs).............so i presume
you could just use it as a sort of hard drive then?

Are it's speeds similar to USB 2.0  since i could also boot
from USB right......


thanks
C

[Juanito]

You should see the microSD as /dev/mmcblk*

I guess the speed depends on the interface and the card quality. There is also reliability to think about.

[vinceASPECT]

okay thanks

[mocore]

...i looked breifly .. and found

https://en.wikipedia.org/wiki/SD_card#Speed

https://www.pcworld.com/article/393331/why-your-laptops-sd-card-reader-might-be-terrible.html

+ https://www.youtube.com/watch?v=2U0-0IGTwc4 (Speed test: Laptop SD card slot vs. SD card readers vs. camera USB)


i think perhaps bootloader/hw driver might also have impact 

+ *some more low level hw* must connect the sd to the laptop/pc
how that is configured / acessed likely will have some impact

eg see the codeblock which contains '# Intialize SPI peripheral' in the below link
https://www.digikey.co.uk/en/maker/projects/raspberry-pi-pico-rp2040-sd-card-example-with-micropython-and-cc/e472c7f578734bfd96d437e68e670050

[gadget42]

@mocore, huge thanks for your post and good articles!

we've all probably come up against poor performing hardware of all kinds/types.

definitely buyer-beware, buyer-be-aware, and always do maximum permissable due-diligence

[patrikg]

To continue the sd card road, have you seen the leepspvideo for raspberry pi and sd cards speeds ?

Raspberry Pi 5 Vs Pi 4. micro sd speed tests
https://youtu.be/DcyCrUv-MLw

[xyz-worx]

Hi vinceASPECT,

I fully agree with Juanito. I made my own (bad) experiences with SD-cards
as a boot device. Take a look at this post:

https://forum.tinycorelinux.net/index.php/topic,23724.msg148850.html#msg148850

Maybe it helps.

best xyz-worx

[gadget42]

To continue the sd card road, have you seen the leepspvideo for raspberry pi and sd cards speeds ?

Raspberry Pi 5 Vs Pi 4. micro sd speed tests
https://youtu.be/DcyCrUv-MLw

for those who don't have the time or patience to wade through the _tube_ insanity:

Code: [Select]

Results: All Pi4 except 128 samsung EVO Pi5 test

braveeagle 32GB
Sequential write speed 21896 KB/sec (target 10000) - PASS
Random write speed 1123 IOPS (target 500) - PASS
Random read speed 3825 IOPS (target 1500) - PASS

alertseal 32GB
Sequential write speed 27970 KB/sec (target 10000) - PASS
Random write speed 1095 IOPS (target 500) - PASS
Random read speed 3796 IOPS (target 1500) - PASS

Adroitlark 32GB
Sequential write speed 36571 KB/sec (target 10000) - PASS
Random write speed 948 IOPS (target 500) - PASS
Random read speed 3656 IOPS (target 1500) - PASS

Kingston 64GB Canvas Go plus A2
Sequential write speed 32251 KB/sec (target 10000) - PASS
Random write speed 1521 IOPS (target 500) - PASS
Random read speed 3621 IOPS (target 1500) - PASS

Samsung EVO select 128GB Pi4
Sequential write speed 30159 KB/sec (target 10000) - PASS
Random write speed 731 IOPS (target 500) - PASS
Random read speed 3400 IOPS (target 1500) - PASS

Samsung EVO select 128GB Pi5
Sequential write speed 46315 KB/sec (target 10000) - PASS
Random write speed 818 IOPS (target 500) - PASS
Random read speed 4220 IOPS (target 1500) - PASS

Magix 32GB A1
Sequential write speed 14021 KB/sec (target 10000) - PASS
Random write speed 1188 IOPS (target 500) - PASS
Random read speed 3333 IOPS (target 1500) - PASS

Lexar 1066 64GB
Sequential write speed 33956 KB/sec (target 10000) - PASS
Random write speed 712 IOPS (target 500) - PASS
Random read speed 3278 IOPS (target 1500) - PASS

Sandisk 64GB Extreme A2 From GoPro
Sequential write speed 32204 KB/sec (target 10000) - PASS
Random write speed 894 IOPS (target 500) - PASS
Random read speed 2077 IOPS (target 1500) - PASS

tcell masstige 64gb
Sequential write speed 22938 KB/sec (target 10000) - PASS
Random write speed 510 IOPS (target 500) - PASS
Random read speed 1938 IOPS (target 1500) - PASS


[mocore]

@mocore, huge thanks for your post and good articles!

we've all probably come up against poor performing hardware of all kinds/types.

definitely buyer-beware, buyer-be-aware, and always do maximum permissable due-diligence

scrolling past the below quote (spesificly : compatible devices/testing conditions) reminded me of this topic
https://www.samsung.com/uk/memory-storage/memory-card/evo-plus-256gb-microsd-card-mb-mc256ka-eu/

Performance

    Speed
 Read : up to 130MB/s
 Write : Lower than Read Speed*
Read/Write speed requires compatible devices capable of reaching such speeds
and it may vary among different host devices and testing conditions.
* For products incompatible with UHS-I interface, the speeds may vary subject to different interface conditions

wrt/for varying degrees of 
>maximum permissable due-diligence

see also : Exploration and Exploitation of an SD Memory Card (by xobs & bunnie)
https://media.ccc.de/v/30C3_-_5294_-_en_-_saal_1_-_201312291400_-_the_exploration_and_exploitation_of_an_sd_memory_card_-_bunnie_-_xobs