I have 3 ivy bridge PCs with ASrock extreme LGA 1155 boards. 2 extreme4s, 1 extreme6. Specs vary slightly, but all have: ivy bridge cpus, samsung ssd boot drives on intel sata3_0, 2TB seagate hdd on intel sata3_1, blu-ray writers on intel sata2_xx, win8 64-bit.

I keep ASmedia sata3_A2 (or sata3_A1, for the extreme4s) clear on all 3 PCs, in order to use the rear eSATA port for backup duties.

The 2 extreme4 PCs hot-plug-initialize my backup drives with no problem, but the extreme6 one is very balky. I'll hear the system sound I'm supposed to hear when hot-plugging, but often the drive can't be read, or I'll quickly hear the 'unplug' sound even though I didn't unplug it.

Usually I can eventually get the drive to be seen & usable, but only after repeated plugging/unplugging/replugging.

I have multiple esata cables and bare-drive-docks (e.g. MassCool), and multiple backup drives, and have tried all of them on all three PCs. All work fine on the extreme4 pcs; all are balky on the extreme6. All 3 pcs have ASMedia sata3 driver 1.3.8.

BIOS (whoops, UEFI) configurations are similar for all three PCs. Both intel & ASmedia sata are set to AHCI, and 'sata boot ROM' for asmedia is disabled.

I can't imagine what the problem is here, other than a physical defect of some kind in the port connector or circuitry. Any ideas would be appreciated.

Also, the extreme6 board does one other weird thing that the extreme4s don't. The mobo speaker occasionally emits random short single beeps--not during boot or shutdown, but while windows is up and running. I have no idea what it's trying to tell me. These are not related to hot-plugging my esata drives. I can go for days without ever hearing them, but then will hear them for several days in a row. Nothing seems wrong in terms of performance, I've never had a bluescreen or any indication from Windows of a problem. Nothing is overclocked. Again, any ideas would be appreciated.

fwiw, here are the extreme6 PC specs.

cpu - intel ivy br i7 3770K
fan - Cooler Master Hyper 212 Plus
ssd - samsung 840pro 256gb, on sata 3_0
ram - 16 gb gskill ripjaws x ddr3 1866 (2 x 8gb, slots 2 & 4)
hdd - seagate barrac 2TB, on sata 3_1
bd-RW - asus blu-ray burner SATA BW-12B1ST, on sata 2_5
video - gigabyte GeForce GTX 660 2GB, running 3 monitors
sound - xonar essence stx
psu - corsair cs600M

The extreme4 pcs are similar, but mostly use components 1 or 2 notches below these (e.g., samsung 830, intel i5 3470K, etc.)

Thanks again for any ideas.