I'm writing you all to ask about USB3 on G5s. I did check prior posts, which mostly said no way. However, on macsales.com there are multiple options for PCI-e cards that support USB3 on G5s (on late model G5s running 10.5.8), e.g. http://eshop.macsales.com/item/CalDigit/U3HOSTADPTR/ I own an old but working-flawlessly dual-2.3 late-2005 PMG5. The PMG5 is presumably v1 PCI-e and I don't know what the peak speed, if it works under OS 10.5.8, could be achieved (probably 3 Gb/s). I'm trying to do better than FW800, and I'd just as soon skip eSATA. To those 'buy a new mac' questions, I own a retina MBP at work and i5 MBP at home. But USB3 would be a nice addition to the MBP. Anyone try this? As I understand it FW### is DMA and USB is not ,so even if it works it may drag down the processor - but I'd like the option for moving large-ish (100s GB, not TBs) files around. Thanks for any comments.