pica200
Posts: 138
Joined: Tue Aug 06, 2019 10:27 am

Re: Fastest Micro SD card for Pi 4? Does it support XC U3?

Tue Aug 20, 2019 8:31 pm

As someone in the comments of the blogpost pointed out there seems to be support for command queue already which makes me wonder what is going on? https://github.com/raspberrypi/linux/bl ... st/cqhci.c

Is that driver not stable yet? Is it exclusively for eMMC?

Rasp16
Posts: 2
Joined: Fri Sep 13, 2019 9:07 pm

Re: Fastest Micro SD card for Pi 4? Does it support XC U3?

Sat Sep 14, 2019 1:26 pm

This guy tested several micro SD cards on Raspberry pi 4 4 iops speed
www.pidramble.com/wiki/benchmarks/microsd-cards

ejolson
Posts: 3585
Joined: Tue Mar 18, 2014 11:47 am

Re: Fastest Micro SD card for Pi 4? Does it support XC U3?

Sat Sep 14, 2019 4:41 pm

Rasp16 wrote:
Sat Sep 14, 2019 1:26 pm
This guy tested several micro SD cards on Raspberry pi 4 4 iops speed
www.pidramble.com/wiki/benchmarks/microsd-cards
An interesting comparison. As cards age they slow down due to the need for wear leveling. Strangely, it would appear that
  • Only one card of each type was tested.
  • The age of each card was not mentioned.
  • Links are provided to Amazon but no output from commands such as hwinfo disc to verify manufacturer and batch number.
  • The raw data from the benchmark runs was not provided preventing further analysis and interpretation.
  • No mention of wear leveling or whether steps like filesystem trim were performed to help mitigate those effects.
While such oversights are common in the journalistic coverage of science, engineering and technology, on a positive note, a script and discussion of how to download and install the software used to perform the tests was provided at the end of the report. Moreover, even with some information about the SD cards missing, the comparison between different Pi models is quite interesting.

I wonder if the same cards would still give the same results if run through the tests a second time.

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