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micro SDs card for Pinebook Pro
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01-14-2020, 05:57 PM
I want to buy 2 micro SD cards for running of alternative OSes.
The faster the more expensive  . What speed class may be a sensible tradeoff?
01-14-2020, 07:32 PM
I use SanDisk Ultras to boot a lot of things, including Manjaro on my PBP, they all work great and are very well priced. (Best Buy price matches SanDisk's Amazon listings, too.)
01-14-2020, 11:19 PM
If you really want to know how fast a uSD (or any storage) is
iozone -e -I -a -s 100M -r 4k -r 16k -r 512k -r 1024k -r 16384k -i 0 -i 1 -i 2 Pay attention to the 4K and 16K speeds, esp random writes You will be SHOCKED until you have done a few It's hard to beat samsung evo (any version), don't get 16GB, they are slower They are NOT marked A1 or A2 The high speeds shown are probably bogus, cached (too high to be believable) But I suspect the PBP uSD slot is 50 mHz so top speed is limited to ~23MB/s (for test, in a usb3 dongle, in usb3 slot, I think most usb3 dongles do uhs104)
OK, I am glad to say I was wrong, the uSD slot is 200? mHZ
For your edification,, this with iozone on PBP (debian iozone does not want -l, BTW) This, I think, is the fastest uSD I have ever tested, most will have 4k <10000,,, crap cards 1000 or less (numbers are K/s) Samsung EVO Select 64G random random kB reclen write rewrite read reread read write 102400 4 17313 17328 649082 704138 651892 17466 102400 16 25964 17453 974273 810781 712337 18438 102400 512 20166 30826 921817 916929 1070827 18496 102400 1024 16714 29684 900426 891031 836840 30842 Oops, damn forum SW messed up my table formating, when I try to edit looks fine, sorry
01-15-2020, 04:28 PM
Here on the forum you can probably find what works best with the different Pine devices.
but I think most class 10 will do a satisfactory job of "loading" an OS, but if you are "running" from an SD card, some may perform better.
LINUX = CHOICES
**BCnAZ**  Donate to $upport your favorite OS Team
you know (or maybe you don't) that armbian has been making images for
SBC for maybe 4? years now? All of these SBC run and boot from uSD There is a reason (hard won experience) that they say.... Is the card crap? Have you tested it? Lots of speed 10 cards are inadequate to run an OS, If the card does poorly with iozone, it won't work very well at all A1 or A2 is a much better indicator of quality for OS use Oh, BTW, I have run iozone on maybe 30-40 different cards, FWIW
@wdt
Perhaps you could share/post those some where on this site, share your experiences with those cards.. ?
LINUX = CHOICES
**BCnAZ** Donate to $upport your favorite OS Team
01-15-2020, 09:53 PM
(This post was last modified: 01-15-2020, 10:24 PM by wdt.
Edit Reason: table formatting
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Well, this seems to be a good spot, labeled and all
All the tests are from 1-2 years ago, I can summarize This is from my own research and following armbian/tkaiser, and trying to find out how to use flash "best" The people who really test the longevity are those using dash-cams Rare for a card to last a year, but that is a single threaded job The cards controller is doing all kinds of things, "behind your back" and web browser keep a cache, just checked ,, 400M, gets really laggy waiting to write updates, also apt-get dist-upgrade can take hours with a crap card Anyway, the #1 rule,ALWAYS check for fakes, the first time it is in your hand (f3 or h2testw) Even amazon has sold fakes Cards were originally made for cameras, a simple job, 1 write, 1 read Try taking 3 photos quickly, doesn't work so well does it? anyway, no name cards always have poor 4k and 16k speeds ~ or< 1000 Brand name (sandisk, kingston, lexar, etc) are often OK, but not exceptional (1000-3000) Generally evo are better, sometimes only a bit, sometimes 50% (not the 16G,,only OK) I have stopped buying "crap" cards unless they are REALLY cheap, those I ALWAYS test right away (well, I always test), and I wouldn't use them for an OS Here another,,samsung evo plus 64G (not sure if same as evo+) random random kB reclen write rewrite read reread read write 102400 4 3927 4100 10320 10313 10165 2640 102400 16 6460 10519 25852 25728 25699 10796 102400 512 25605 20796 82719 82950 76700 27167 102400 1024 23151 22794 84709 84991 81562 20229 102400 16384 23476 25132 85421 86309 86470 26595 These are "typical" good speeds, anything 1/2 (or<)the 4k and 16k speed is not fit for an OS And something different, a 32G eMMC module, all usb3 (sandisk,, from amerdroid?) I don't know why so slow random random kB reclen write rewrite read reread read write 102400 4 4247 4289 6256 6290 5368 4205 102400 16 11641 11937 19502 19549 11819 11961 102400 512 40563 43955 47143 47122 36640 38861 102400 1024 40829 44497 47316 47248 41644 41384 102400 16384 40857 44390 47338 47354 46975 44020 Really you have to test yourself, a slow card will give disappointing results The last 2 columns should have 'random' over them  (01-15-2020, 04:14 PM)wdt Wrote: OK, I am glad to say I was wrong, the uSD slot is 200? mHZwow, 900MB/s, what's the mode of operation it is? looks like the freshly invented SDe.  you probably forgot to assign the flag for the direct operation to the storage. and I forgot it too, and cannot check now. anyway, Rockchip makes the input frequency for the SDMMC controllers at 150MHz, so when possible, even SDR104 will be SDR75 only. which is not that bad.and honestly, while I don't insist, I can't get the hype about A1/A2 classes. that often are promoted almost like panacea. first, it's just markings without too much of explanation on what's behind it (the whole IOPS magic is pretty obscure) and second, flash based storages don't have such a drastic difference between sequential and random IO (tests kind of prove that). it's random inside anyway. also, for boot/start up time speed up, high sequential read speed is important too. it's advantageous not only for "taking selfies and filming stupid instastories", as A1/A2 believers often tell. but of course, if one has the the will to spend a little bit more, than the more expensive the better. if not fake.
ANT - my hobby OS for x86 and ARM.
01-16-2020, 04:44 AM
(01-15-2020, 06:31 PM)wdt Wrote: you know (or maybe you don't) that armbian has been making images for The mass-market use of SD-card for linux root started with Raspberry Pi nearly 8 years ago. One of the guys who has done a lot of work to understand their performance is Jeff Geerling. I have put a link to him in the Resources section of the PinePhone software page as well. TL;DR - Samung Evo+ (and my 64G is faster than my 32G is faster than my 128G IIRC at 4k writes!)
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