raymate
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Fast Memory Cards

Sat Apr 02, 2016 3:41 pm

Technically does anyone know how fast the Pi's can read and write to a memory card?

I have various cards ranging from cheap to not, so basic 10w/40r to 45w/90r and I was just about to pickup a 90w/95r

But does the Pi even work the very fast speeds some cards can now reach?
_______________________________________
Pi model B / Pi 2 / Pi 3 / Pi 4 / Pi Zero W

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GTR2Fan
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Location: South East UK

Re: Fast Memory Cards

Sat Apr 02, 2016 3:50 pm

Roughly 45MB/s read/write if you overclock the card slot to 100MHz. Any more is a waste and is probably stealing from a card's small file read/write performance. Have a Google for CrystalDiskMark reports until you find a card that tops out at around 45MB/s sequential whilst giving the best 4K read/write performance. That would be the sweetspot.
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

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Flagbit
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Re: Fast Memory Cards

Sat Apr 02, 2016 10:57 pm

Someone tested some SD-cards for the PI2:
http://www.jeffgeerling.com/blogs/jeff- ... crosd-card
-- My 2 Cents, Coin Heatsink: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=141441
-- Snappy Pi 3: Coin Heatsink, 1300Mhz Overclocked stable (could void warranty), Ubuntu-Mate on USB-stick

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GTR2Fan
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Joined: Sun Feb 23, 2014 9:20 pm
Location: South East UK

Re: Fast Memory Cards

Sun Apr 03, 2016 11:50 am

That's an interesting read, Flagbit. It's also further proof that a good microSD card can easily match or even beat a USB-connected mechanical hard drive, especially on small file reads/writes where even the best spinners often struggle to exceed a miserable 1MB/s. Overclock the card slot as well if it's a UHS-rated card and you can be miles ahead on typical spinner I/O performance.
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

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Flagbit
Posts: 37
Joined: Tue Mar 22, 2016 11:03 pm
Location: Earth, 51.316°N 9.393°E

Re: Fast Memory Cards

Sun Apr 03, 2016 12:23 pm

Nice to see the link I found is useful.

How about wear leveling of the SD-card?
And with overclocking, does it affect some temperature rise in the SD-card or somewhere else?

For long term use, would it be the best to switch to a SSD USB Drive?

Kind Regards
Flagbit
-- My 2 Cents, Coin Heatsink: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=141441
-- Snappy Pi 3: Coin Heatsink, 1300Mhz Overclocked stable (could void warranty), Ubuntu-Mate on USB-stick

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