Thank you , thats a very good tip . PCIE 3.0 and 6 ports, that is excellent.For SATA, ASMedia chips seem to consume less power and are more stable than Marvell chips.
Edit: This is ASM1166.
Well, after my last post a couple of weeks later the 6-port SATA card arrived and I set about replacing the HBA with it.
To my surprise the machine booted up and all the problems went away. The reason I didn't reply since May is because I didn't believe it. So I wanted to be absolutely sure that the problem had gone away for good.
As such I hammered the machine non stop over the summer, where outside temps here exceed 40°C. I only had the machine die on two occasions, both of them when the CPU exceeded 105°C, which I think is an internal over-temp cutoff.
After 4 months of stress...