Author Topic: microSD speed  (Read 2251 times)

mithrandir

  • Full Member
  • ***
  • Posts: 191
    • View Profile
    • http://www.mygnu.de
microSD speed
« on: March 02, 2018, 08:38:12 pm »
Hi,
has anybody already performed a speed test (i.e. hdparm -t) with the geminis micro sd interface?

I am currently thinking about which kind of card to use with the gemini. From my point of view there are two options:

1. Use a high endurance card to ensure it lasts a while.
These seem to max out at 64GB and 20MB/s (read with hdparm). At least this is what I have been able to get out of the Sandisk one with my laptop.

2. Use a high performance / larger card

Any thoughts/experiences on that? Are there other high enduarance cards which are larger/support higher speeds.

Regards
mith

Hitherwood

  • Newbie
  • *
  • Posts: 19
    • View Profile
    • http://
microSD speed
« Reply #1 on: March 03, 2018, 03:34:59 pm »
Quote from: mithrandir
Hi,
has anybody already performed a speed test (i.e. hdparm -t) with the geminis micro sd interface?

I am currently thinking about which kind of card to use with the gemini. From my point of view there are two options:

1. Use a high endurance card to ensure it lasts a while.
These seem to max out at 64GB and 20MB/s (read with hdparm). At least this is what I have been able to get out of the Sandisk one with my laptop.

2. Use a high performance / larger card

Any thoughts/experiences on that? Are there other high enduarance cards which are larger/support higher speeds.

Regards
mith
Entirely depends what you want the PDA to do. Not sure what you mean by "high endurance" as this describes nothing technical!

If you want 4K video (little point on a small screen) then opt for 90MB/s
If you simply want to dump Docs/PDFs then anything will do

For myself, I bought a Samsung Evo Plus (3) rated 128Gb card because I love high definition audio (via headphones socket)

mithrandir

  • Full Member
  • ***
  • Posts: 191
    • View Profile
    • http://www.mygnu.de
microSD speed
« Reply #2 on: March 03, 2018, 05:52:54 pm »
Quote from: Hitherwood
snip
Entirely depends what you want the PDA to do. Not sure what you mean by "high endurance" as this describes nothing technical!

If you want 4K video (little point on a small screen) then opt for 90MB/s
If you simply want to dump Docs/PDFs then anything will do

For myself, I bought a Samsung Evo Plus (3) rated 128Gb card because I love high definition audio (via headphones socket)
These high endurance cards are designed for video recording, i.e. dashcams. Some reported these cards to last longer, when using as system disk for raspberrys. However, I have not found any reliable information on this. Originally I used a Sandisk class 10 in my banana pi router running debian, which broke after aproximately half a year (logging, etc). After I replaced it with one of these the system works without problems for longer than a year.  So if it does not make a huge difference in speed it might make sense to use one of these to avoid it getting broken due to heavy use.

Hitherwood

  • Newbie
  • *
  • Posts: 19
    • View Profile
    • http://
microSD speed
« Reply #3 on: March 04, 2018, 04:05:10 pm »
Quote from: mithrandir
Quote from: Hitherwood
snip
Entirely depends what you want the PDA to do. Not sure what you mean by "high endurance" as this describes nothing technical!

If you want 4K video (little point on a small screen) then opt for 90MB/s
If you simply want to dump Docs/PDFs then anything will do

For myself, I bought a Samsung Evo Plus (3) rated 128Gb card because I love high definition audio (via headphones socket)
These high endurance cards are designed for video recording, i.e. dashcams. Some reported these cards to last longer, when using as system disk for raspberrys. However, I have not found any reliable information on this. Originally I used a Sandisk class 10 in my banana pi router running debian, which broke after aproximately half a year (logging, etc). After I replaced it with one of these the system works without problems for longer than a year.  So if it does not make a huge difference in speed it might make sense to use one of these to avoid it getting broken due to heavy use.

There is nothing in the SD card specification about "high endurance". All Flash memory, by nature, starts to decay from the moment you use it. Typically, it might last for 100,000 write cycles. Some companies offer lifetime guarantee, but that means a replacement card and loss of data.Modern cards include wear-leveling to avoid hotspots. As an IT Technician in a secondary school, my guess is that 75% of cards are destroyed by static electricity! Don't finger the contacts and don't run defrag or optimisation on them.