Samsung Pro Endurance microSDXC 128GB

* hdparm -t: Timing buffered disk reads: 52 MB in 3.10 seconds = 16.80 MB/sec
* hdparm -T: Timing cached reads: 3436 MB in 2.00 seconds = 1719.28 MB/sec

# flashbench -a /dev/sdd --blocksize=1024
align 34359738368 pre 502µs on 593µs post 530µs diff 77µs
align 17179869184 pre 538µs on 597µs post 509µs diff 74.1µs
align 8589934592 pre 524µs on 599µs post 501µs diff 86.4µs
align 4294967296 pre 567µs on 640µs post 532µs diff 90.8µs
align 2147483648 pre 548µs on 646µs post 534µs diff 105µs
align 1073741824 pre 544µs on 652µs post 530µs diff 114µs
align 536870912 pre 550µs on 641µs post 528µs diff 102µs
align 268435456 pre 541µs on 635µs post 566µs diff 81.5µs
align 134217728 pre 494µs on 602µs post 500µs diff 105µs
align 67108864 pre 544µs on 630µs post 530µs diff 93.3µs
align 33554432 pre 528µs on 646µs post 533µs diff 115µs
align 16777216 pre 518µs on 634µs post 541µs diff 105µs
align 8388608 pre 532µs on 529µs post 537µs diff -5560ns
align 4194304 pre 546µs on 540µs post 550µs diff -7164ns
align 2097152 pre 538µs on 542µs post 558µs diff -6592ns
align 1048576 pre 566µs on 551µs post 554µs diff -9238ns
align 524288 pre 586µs on 540µs post 533µs diff -19417n
align 262144 pre 547µs on 579µs post 551µs diff 30.3µs
align 131072 pre 549µs on 571µs post 530µs diff 30.9µs
align 65536 pre 559µs on 561µs post 533µs diff 15.8µs
align 32768 pre 528µs on 546µs post 528µs diff 18.6µs
align 16384 pre 531µs on 551µs post 554µs diff 7.75µs
align 8192 pre 558µs on 548µs post 543µs diff -2634ns
align 4096 pre 544µs on 533µs post 535µs diff -6448ns
align 2048 pre 535µs on 534µs post 551µs diff -9341ns

=> Erasureblocksize = 16 MiB
→ ext4 stripe-width=16 MiB/8 KiB=2048 =>
mkfs.ext4 -E stride=2,stripe-width=2048

Niet optimaal gepartitioneerd geeft een 2GB Rpi4B met 5.10.14-1-ARCH en ext4 deze "bonnie++ -n 0" resultaten:
[pre]
Version 1.98 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Name:Size etc /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
influxPi4B 4G 248k 99 31.7m 9 14.2m 4 1141k 99 41.4m 4 1080 22
Latency 35876us 2309ms 2584ms 8008us 28095us 3273us
[/pre]


Zodra de partities op 16MiB uitgelijnd worden en met stride=2,stripe-width=2048:
[pre]
Version 1.98 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Name:Size etc /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
influxPi4B 4G 248k 98 31.3m 9 16.4m 5 1066k 99 41.4m 4 1834 36
Latency 32073us 1408ms 1368ms 8376us 26703us 61324us
[/pre]

en een tweede keer voor de vergelijking:
[pre]
Version 1.98 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Name:Size etc /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
influxPi4B 4G 250k 98 29.9m 9 13.7m 4 1140k 99 41.6m 4 1193 17
Latency 40079us 1533ms 2549ms 7863us 8992us 5189us
[/pre]