Sorry USN, I forgot to mention the Areca controller type:
Areca 1680ix with 4GB cache on-card

These controllers also have several internal SAS/SATA channels, but we only use the 2 external ones.

Until now, no bad expirience (compared to the mess with the Adaptec controllers, nothing “bad” can happen, anyways…).

Meanwhile we removed the Adaptec controllers on all such systems (=6 controllers) and replaced them by technically similar Areca controllers.

The Adaptec controllers constantly made problems, from not reacting on disk exchange to loosing data while doing write operations (which ends up in restoring huge databases here, I did that several times).

Since I installed the Areca controllers, all problems seem to have vanished, the IO is comparable (today a bit better, because I installed 4GB cache each controller) and I never restored a database on those systems since then.