You have only PCI Express slots? Didn't you read my P.S. stating that this is a PCI card that won't work in a PCI Express slot???
There are firewire cards that are made for PCI Express, but that isn't one of them.
Here are some PCI Express cards with T.I. chip:
http://www.amazon.com/gp/product/B002S5 ... T2SERP82TZ" onclick="window.open(this.href);return false;
http://www.outletpc.com/c5556.html" onclick="window.open(this.href);return false;
Can't say whether the above have the additional power connector on them. I know some of the cards that sell for a lot more do. But if you're ok with using the MOTU power adapter, you don't care.