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Read speeds of microSD slot and eMMC - Printable Version

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Read speeds of microSD slot and eMMC - bartgrefte - 12-08-2020

When Googling for the max read speeds, I came across the PinePhone FAQ, which says

Quote:What's the speed difference between the eMMC and SD cards?
Maximum transfer speed of the eMMC is around 85 MB/s, while SD cards are limited to approximately 23 MB/s (even with faster cards).
Do those speeds apply to the PineTab as well? Since both seem to be around 23MBps.

For testing I followed https://www.binarytides.com/linux-test-drive-speed/ , dd'ing a large file to /dev/null.


RE: Read speeds of microSD slot and eMMC - evilbunny - 12-08-2020

(12-08-2020, 02:51 AM)bartgrefte Wrote: When Googling for the max read speeds, I came across the PinePhone FAQ, which says

Quote:What's the speed difference between the eMMC and SD cards?
Maximum transfer speed of the eMMC is around 85 MB/s, while SD cards are limited to approximately 23 MB/s (even with faster cards).
Do those speeds apply to the PineTab as well? Since both seem to be around 23MBps.

For testing I followed https://www.binarytides.com/linux-test-drive-speed/ , dd'ing a large file to /dev/null.


The pinetab and pinephone use the same CPU etc


RE: Read speeds of microSD slot and eMMC - bartgrefte - 12-08-2020

(12-08-2020, 03:19 AM)evilbunny Wrote: The pinetab and pinephone use the same CPU etc
Then I'm curious why Mobian on eMMC shows the same read speed as Mobian on microSD. If the hardware is similar/the same as the PinePhone, shouldn't eMMC have faster read speeds?


RE: Read speeds of microSD slot and eMMC - evilbunny - 12-09-2020

(12-08-2020, 11:01 AM)bartgrefte Wrote:
(12-08-2020, 03:19 AM)evilbunny Wrote: The pinetab and pinephone use the same CPU etc
Then I'm curious why Mobian on eMMC shows the same read speed as Mobian on microSD. If the hardware is similar/the same as the PinePhone, shouldn't eMMC have faster read speeds?

I'm speculating, but maybe it's a software issue in mobian.


RE: Read speeds of microSD slot and eMMC - bartgrefte - 12-09-2020

(12-09-2020, 05:44 AM)evilbunny Wrote: I'm speculating, but maybe it's a software issue in mobian.
The only thing I could thing of, is a partition alignment issue, I checked with parted, no problem there.


RE: Read speeds of microSD slot and eMMC - dukla2000 - 12-09-2020

(12-08-2020, 11:01 AM)bartgrefte Wrote: ...
Then I'm curious why Mobian on eMMC shows the same read speed as Mobian on microSD.
...

Where is the data for that statement? It certainly is NOT true for Mobian on a PinePhone.


RE: Read speeds of microSD slot and eMMC - bartgrefte - 12-15-2020

(12-09-2020, 02:30 PM)dukla2000 Wrote: Where is the data for that statement? It certainly is NOT true for Mobian on a PinePhone.
See 1st post: "For testing I followed https://www.binarytides.com/linux-test-drive-speed/ , dd'ing a large file to /dev/null."
I don't have the exact values at hand, but with both the read speed was between 20-25MBps.


RE: Read speeds of microSD slot and eMMC - bartgrefte - 12-27-2020

(12-09-2020, 02:30 PM)dukla2000 Wrote: Where is the data for that statement? It certainly is NOT true for Mobian on a PinePhone.
mobian@mobian:~/Downloads$ sudo dd if=mobian-pinetab-phosh-20201113.img.gz of=/dev/null bs=64
17384441+1 records in
17384441+1 records out
1112604243 bytes (1.1 GB, 1.0 GiB) copied, 54.7591 s, 20.3 MB/s

Same with microSD.


RE: Read speeds of microSD slot and eMMC - dukla2000 - 12-27-2020

I am not sure dd is that useful for benchmarking.

bs=64 cannot be expected to report any meaningful maximum unless that is your specific use case. From your results it can be easily deduced that the throughput bears little relation to the media which is a bad benchmark if you are trying to compare media. When dumping a 1G file bs=4M is my preference but I still wouldn't use dd to benchmark.


RE: Read speeds of microSD slot and eMMC - bartgrefte - 01-01-2021

(12-27-2020, 05:01 PM)dukla2000 Wrote: I am not sure dd is that useful for benchmarking.
Well, that's what Google came up with when I googled for ways to measure eMMC read speeds.

(12-27-2020, 05:01 PM)dukla2000 Wrote: bs=64 cannot be expected to report any meaningful maximum unless that is your specific use case. From your results it can be easily deduced that the throughput bears little relation to the media which is a bad benchmark if you are trying to compare media. When dumping a 1G file bs=4M is my preference but I still wouldn't use dd to benchmark.
Just tried it with bs=4M, that's showing better read speeds: ~57MBps.