guys, I asked a friend to lend us his card, which is the card2 listed below and not things are becoming really weird card1, Silicon Image, Inc. Adaptec AAR-1210SA card2, Silicon Image, Inc. SiI 3124 PCI-X Serial ATA the card1 is a PCI32 bit card, and uses the "sata_sil" driver the card2 is a PCI64 bit card, and uses the "sata_sil24" driver card1 is installed in a PCI32 slot, and it's moving 32Gbyte in a loop without any issue I have just tested card2 in each of the PCI-X slot (including the 3.3V one) and ... it has always triggered the HPMC unit, crashing the machine the hardware is different, and drivers are also different, but .... maybe the problem is related to 32 vs 64bit? I am going to repeat the test with card2 installed in a PCI32 slot. This should force it to 32bit: will it work correctly? (hope this makes sense) --- we have also checked if the kernel is correctly handling the ram we have a C3600 with 8Gbyte of ram mount -t tmpfs -o size=7G tmpfs /mnt/ramdrive/ dd if=/dev/zero of=/mnt/ramdrive/test.bin badblocks -swv /mnt/ramdrive/test.bin checking for bad blocks in read-write mode >From block 0 to 7340031 Testing with pattern 0xaa: done Reading and comparing: done Testing with pattern 0x55: done Reading and comparing: done Testing with pattern 0xff: done Reading and comparing: done Testing with pattern 0x00: done Reading and comparing: done Pass completed, 0 bad blocks found. no problems found