Q: I have a MacPro 1,1 with a NVIDA GeForce 7300 GT, and want to set up 3 20in monitors HD, Any Ideas?

just go out and buy the Apple Store ATI 5770. It supports those and much better - the 7300GT what I had now in a drawer wtih its 256MB is 7 yrs plus and overdue for ugrade. not the cheapest. But $240

Otherwise there are not a lot and other sites might walk you through the whole flashing PC version

Nope. Low end PC card that will not provide early boot and don't know that it works at all though 10.7.5 might you would have to 'ask' the sites that deal with PC cards rather than Apple which will have Apple EFI firmware which yours lacks.

It will work when you run Windows natively, but that is a big pile of road blocks and other issues.

I said it supports three. by itself.

Apple Mini DisplayPort adapters: Frequently asked questions (FAQ)

http://support.apple.com/kb/HT3382

Guide to Apple graphic display adapters needed

https://support.apple.com/kb/HT3235

Atlona (Dual Link) DVI to Mini DisplayPort Converter for Apple 27-inch LED and 27-inch iMac

http://www.atlona.com/Atlona-Dual-Link-DVI-to-Mini-DisplayPort-Converter-USB-Pow ered.html

Mac Pro (Early 2009), Mac Pro (Mid 2010), Mac Pro (Mid 2012): Issues with three displays and multiple DVI, HDMI connections

It's not the USB data that is needed to run three displays. It's the extra POWER. If you read the Apple article, they say the only solution they endorse is their US$100 Dual-Link adapters. Check the table at the end of the article.

Mac Pro (Early 2009), Mac Pro (Mid 2010): Supported display configurations

If I recall correctly, the HD 5770 requires a PCIe 2.0 slot while the PacPro 1,1 has only a PCI 1.0 slot so the HD 5770 wouldn't work in a PacPRo 1,1.

Am I confused here?

regards

Yes you are misled confused led astry: ATI 5770 works in ALL Mac Pro models with 10.6.5 and above.

Posting on a "solved" thread doesn't help you or I.

And if you read comments on Apple product page there are many 1,1 owners.

Barefeats.com compares performance in all models and against 5870 (which also works).

I mean look at 3 yrs of threads saying this same thing, over and over - there is one monster thread still active.