Digikam. rychlost převodu databáze

uklízím i v počítači a jednu z vecí, které dělám je převod databáze digikamu z verze 4 na 5. obě databáze jsou lokalizovány na SSD (jednom) ve dvou různých adresářích. A jede to jako šnek.

A když si vypíšu zátěž, kterou má počítač v atop dostanu

RC | sys    9.18s | user   9.66s |              |               | #proc    342 | #trun      4 | #tslpi   667 | #tslpu     3 | #zombie    0 | clones     1  |              |              | #exit      0 |
CPU | sys      82% | user     86% | irq       4% |               |              | idle    512% | wait    116% |              | steal     0% | guest     0%  |              | avgf 1.85GHz | avgscal  56% |
cpu | sys      14% | user     14% | irq       0% |               |              | idle     48% | cpu004 w 23% |              | steal     0% | guest     0%  |              | avgf 2.00GHz | avgscal  60% |
cpu | sys      12% | user     14% | irq       1% |               |              | idle     58% | cpu002 w 15% |              | steal     0% | guest     0%  |              | avgf 1.99GHz | avgscal  60% |
cpu | sys      12% | user     15% | irq       1% |               |              | idle     44% | cpu006 w 29% |              | steal     0% | guest     0%  |              | avgf 1.99GHz | avgscal  60% |
cpu | sys      14% | user     14% | irq       1% |               |              | idle     58% | cpu000 w 14% |              | steal     0% | guest     0%  |              | avgf 1.97GHz | avgscal  59% |
cpu | sys      10% | user      6% | irq       0% |               |              | idle     76% | cpu003 w  7% |              | steal     0% | guest     0%  |              | avgf 1.71GHz | avgscal  51% |
cpu | sys       6% | user      8% | irq       1% |               |              | idle     70% | cpu001 w 15% |              | steal     0% | guest     0%  |              | avgf 1.72GHz | avgscal  52% |
cpu | sys       8% | user      7% | irq       1% |               |              | idle     76% | cpu007 w  9% |              | steal     0% | guest     0%  |              | avgf 1.69GHz | avgscal  51% |
cpu | sys       7% | user      8% | irq       1% |               |              | idle     80% | cpu005 w  5% |              | steal     0% | guest     0%  |              | avgf 1.70GHz | avgscal  51% |
CPL | avg1    6.28 |              | avg5    5.04 |  avg15   4.40 |              |              | csw   514992 |              | intr  259261 |               |              | numcpu     8 |              |
MEM | tot    23.5G | free  192.4M | cache  14.2G |  dirty   2.9G | buff    4.9G | slab  572.7M | slrec 438.3M | shmem 140.2M | shrss 138.5M | shswp   0.0M  | vmbal   0.0M | hptot   0.0M | hpuse   0.0M |
SWP | tot     4.0G | free    4.0G |              |               |              |              |              |              |              |               | vmcom   6.0G |              | vmlim  15.8G |
PAG | scan  264304 | steal 264302 |              |  stall      0 |              |              |              |              |              |               | swin       0 |              | swout      0 |
LVM |       crroot | busy     96% |              |  read      10 | write   6096 | KiB/r     61 | KiB/w     14 |              | MBr/s    0.1 | MBw/s    8.8  | avq     1.06 |              | avio 1.50 ms |
LVM |     _dev_sdd | busy     24% |              |  read     436 | write      0 | KiB/r    830 | KiB/w      0 |              | MBr/s   35.3 | MBw/s    0.0  | avq     5.19 |              | avio 5.37 ms |
DSK |          sdf | busy    104% |              |  read       0 | write   2831 | KiB/r      0 | KiB/w    118 |              | MBr/s    0.0 | MBw/s   32.8  | avq   143.28 |              | avio 3.53 ms |
DSK |          sda | busy     94% |              |  read      10 | write   5975 | KiB/r     61 | KiB/w     15 |              | MBr/s    0.1 | MBw/s    8.8  | avq     1.04 |              | avio 1.50 ms |
DSK |          sdd | busy     22% |              |  read     581 | write      0 | KiB/r    622 | KiB/w      0 |              | MBr/s   35.3 | MBw/s    0.0  | avq     6.13 |              | avio 3.72 ms |
NET | transport    | tcpi     844 | tcpo    1150 |  udpi     254 | udpo     294 | tcpao    193 | tcppo      0 |              | tcprs    217 | tcpie      4  | tcpor     44 | udpnp      0 | udpie      0 |
NET | network      | ipi     1111 |              |  ipo     1663 | ipfrw      0 | deliv   1111 |              |              |              |               | icmpi     13 |              | icmpo      2 |
NET | enp6s0    0% | sp 1000 Mbps | pcki    1111 |  pcko    1663 | si  116 Kbps | so  509 Kbps |              | coll       0 | mlti       0 | erri       0  | erro       0 | drpi       0 | drpo       0 |

podstatné je, že zátěž crroot, což je blokové zařízení sda po rozšifrování je na 96% a stejně tak přímo sda je na 90+% přičemž datový tok je pouze kolem 10MB/s. Proč? FS je btrfs, disk Samsung 840 Evo 256G.

Dotaz: Digikam. rychlost převodu databáze