Page 1 of 1

Fast Memory Cards

Posted: Sat Apr 02, 2016 3:41 pm
by raymate
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?

Re: Fast Memory Cards

Posted: Sat Apr 02, 2016 3:50 pm
by GTR2Fan
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.

Re: Fast Memory Cards

Posted: Sat Apr 02, 2016 10:57 pm
by Flagbit
Someone tested some SD-cards for the PI2:
http://www.jeffgeerling.com/blogs/jeff- ... crosd-card

Re: Fast Memory Cards

Posted: Sun Apr 03, 2016 11:50 am
by GTR2Fan
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.

Re: Fast Memory Cards

Posted: Sun Apr 03, 2016 12:23 pm
by Flagbit
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