I have a mining rig, with 2 PCIe (already being used) and 4 PCIs without use. I was thinking to buy a PCI based ATI card like http://www.club-3d.com/index.php/products/reader.en/product/radeon-hd-5450-pci-noiseless-edition.html but I was wondering if anybody has experience running PCI GPUs to mine.
EDIT: to avoid off-topic:
I'm not interested in FPGA or ASIC. I just want to know if the card cited is able to, for example, do opencl.