In a Z600 I put the card in the very top PCIe slot, just above the top video card.

The Molex brand part number is 88751-1311. You can carve on the rubber some, or buy a perfect fitting adapter which I have located, via, made by Molex itself. the card will need a supplemental power source, and this HP card's SATA power connector has tolerances that precludes many SATA power adapters from fitting perfectly. The +5V DC that USB 2 and 3 lives on does not come up from the PCIe slots. You can run this card in a xw6400 or xw8400 but will only get about 1/2 USB 3 speeds. Same idea for the xw8400 versus the xw8600. So, in the xw6600 put the USB 3 card in the second (lower) PCIe x16 video slot so you get the bandwidth that at least matches what USB 3 can do. In the Z workstations the PCIe slots are at least Generation II, but for the xw workstations in the xw6400 none are, and in the xw6600 only the two PCIe x16 video slots are. I've been wanting to post this info for some time, and am building up a Z600 so took some pictures.

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