Upgrade from 10.4.11 to 10.9 on a Mac Pro I have an old Mac Pro with the following serial number G87391T6UPZ. Can I upgrade this computer to 10.9 or 10.10?

I can't seem to find an official website that tells me 'yes' or 'no'. It runs on a 2.66 Ghz Quad-Core Intel Xeon.  There was a website that mentioned early 2008 and up can upgrade. But not sure when this was made...

Edit:

It says it is MacPro 1,1
There is only one available 2.66 GHZ Quad-Core Intel Xeon Mac Pro, which actually is powered by two 2.66 GHz dual core Intel Xeon 5150 processors: MacPro1,1

The maximum OS is Mac OS X 10.7.5, if the RAM was upgraded to at least 2 GB.