PCI I-RAM Working Without A PCI Slot

[Gnif] had a recent hard drive failure in his home server. When rebuilding his RAID array, he decided to update to the ZFS file system. While researching ZFS, [Gnif] learned that the file system allows for a small USB cache disk to greatly improve his disk performance. Since USB is rather slow, [Gnif] had an idea to try to use an old i-RAM PCI card instead.

The problem was that he didn’t have any free PCI slots left in his home server. It didn’t take long for [Gnif] to realize that the PCI card was only using the PCI slot for power. All of the data transfer is actually done via a SATA cable. [Gnif] decided that he could likely get by without an actual PCI slot with just a bit of hacking.

[Gnif] desoldered a PCI socket from an old faulty motherboard, losing half of the pins in the process. Luckily, the pins he needed still remained. [Gnif] knew that DDR memory can be very power-hungry. This meant that he couldn’t only solder one wire for each of the 3v, 5v, 12v, and ground pins. He had to connect all of them in order to share the current load. All in all, this ended up being about 20 pins. He later tested the current draw and found it reached as high as 1.2 amps, confirming his earlier decision. Finally, the reset pin needed to be pulled to 3.3V in order to make the disk accessible.

All of the wires from his adapter were run to Molex connectors. This allows [Gnif] to power the device from a computer power supply. All of the connections were covered in hot glue to prevent them from wriggling lose.