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microSDXC card for Galaxy S9... what is adequate?

Muse

Lifer
Jul 11, 2001
27,389
2,299
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My Sandisk Extreme 256GB microSDXC card with adapter arrived yesterday from B&H Foto.

I put the card in the included adapter and into the card reader in this 2018 Lenovo Thinkpad P1 laptop and tested with h2testw.exe Version 1.4. The results concern me. The write speed isn't terrible but I expected a much faster read speed.

The Samsung Galaxy S9 has rated performance with a capable microSD card of 100mbps read and 90mbps write. I expected the Sandisk Extreme 256GB microSDXC card, which is rated UP TO 160mbps read, 90mbps to have read speeds much better than what the test shows, with read speed only a little faster than write speed. I hope to be doing some pretty high res 4K video to the card. Is the card legit?

H2testw reported this:

Warning: Only 243950 of 243952 MByte tested.
Test finished without errors.
You can now delete the test files *.h2w or verify them again.
Writing speed: 80.7 MByte/s
Reading speed: 88.0 MByte/s
H2testw v1.4

What do you make of this?
 

VirtualLarry

Lifer
Aug 25, 2001
49,163
5,441
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I think UHS-I / U1 is around 100MB/sec tops. Is your reader UHS-II / U3? I think that's what would be needed to realize the full speeds of the card.
 

mxnerd

Diamond Member
Jul 6, 2007
5,519
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126
No problem.


  • Up to 160MB/s read speeds to save time transferring high res images and 4K UHD videos(2); Requires compatible devices capable of reaching such speeds
  • Up to 90MB/s write speeds for fast shooting; Requires compatible devices capable of reaching such speeds
  • 4K UHD and Full HD Ready(2) with UHS speed class 3 (U3) and video speed class 30 (V30)(5)
4K recording only requires 30Mbps.
 
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mxnerd

Diamond Member
Jul 6, 2007
5,519
667
126
Untitled.jpg

Don't trust any SD card for long term storage though. It's easy to go bad any time. Makes backup or move the contents to the PC ASAP.
 
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Muse

Lifer
Jul 11, 2001
27,389
2,299
126
I think UHS-I / U1 is around 100MB/sec tops. Is your reader UHS-II / U3? I think that's what would be needed to realize the full speeds of the card.
I ordered a UHS-I card reader and then saw your post again... cancelled the Amazon order and ordered this slightly costlier UHS-II reader instead. Thanks!

UGREEN USB C Card Reader, USB Type C SD 4.0 UHS-II Dual Slot OTG Card Adapter for iPad Pro 2018, MacBook Pro, Google Pixel, Samsung S10, LG, Micro SD, UHS-II, UHS-I, MMC, Micro SDXC, Micro SDHC

 

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