lol. The ASIC chips don't need the bandwidth that a PCI-E slot has to offer. I like good old USB. I have a potential of running multiple miners off a credit card size $30 Raspberry pi computer. That's not a lot of space needed. For a 4U size, I could run hundreds of GH/s in that space with a pi or two. Mine aren't going in racks, so the pros of standalone aren't needed for me.