Notes:

1.
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As you can see in dmesg for 5.3-BETA1, there is a weird message for
atapci0 (an additional PCI-card called "Promise TX4000 RAID"):

atapci0: <Promise PDC20619 UDMA133 controller> [...]
atapci0: failed: rid 0x20 is memory, requested 4

For 5.2.1-RELEASE this controller doesn't work, please see also the
PR-Database for more details for this problem:
http://www.freebsd.org/cgi/query-pr.cgi?pr=i386/63828

Additonal some Notes from the owner of this board:
"Yes, running perfect with R5.1. And no chance with R5.2.x. Looks like
R5.3 is running fine on it (NO RAID problem anymore) but has a weird
"fail: xxx" message which upseted me (see the attached dmesg)."
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Wie Sie anhand des dmesg-Auszuges von 5.3-BETA1 sehen können, ist eine
seltsame Meldung für atapci0 (PCI-Karte "Promise TX4000") zu erkennen:

atapci0: <Promise PDC20619 UDMA133 controller> [...]
atapci0: failed: rid 0x20 is memory, requested 4

Für 5.2.1-RELEASE funktioniert dieser Controller nicht. Bitte lesen
sie dazu diesen Problemreport:
http://www.freebsd.org/cgi/query-pr.cgi?pr=i386/63828

Noch ein paar Kommentare vom Eigentümer (nicht übersetzt):
"Yes, running perfect with R5.1. And no chance with R5.2.x. Looks like
R5.3 is running fine on it (NO RAID problem anymore) but has a weird
"fail: xxx" message which upseted me (see the attached dmesg)."
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