What is difference between Core 2 Quad Pro and Core 2 Quad

I found two versions of the same processor and the only difference i see is that one of them is 95W Energy Efficient. Is this the only difference? The names of the two products are:

Intel CPU Core 2 Quad Pro Q6600 95W Energy Efficient 2.4GHz SLACR G0 Stepping
Link: http://www.microdirect.co.uk/(2180 [...] nergy.aspx

Intel CPU Core 2 Quad Core Q6600 2.40GHz 1066FSB LGA775 8MB cache (4x2MB)
link: http://www.microdirect.co.uk/(1640 [...] 66FSB.aspx

Please can you tell me why there is a another version of the same processor and if one is better than the other?

Some retailers use the Core 2 Quad Pro as short for Core 2 Quad Processor.

Intel® Core™2 Quad Processor Q6600 is the official name, thus the similarities.

Nonetheless,

Intel® Core™2 Quad Processor Q6600 "G0",

http://processorfinder.intel.com/d [...] spec=slacr

is better than

Intel® Core™2 Quad Processor Q6600 "B3",


http://processorfinder.intel.com/d [...] spec=sl9um

Thus,

get the

Intel® Core™2 Quad Processor Q6600 "G0",

http://www.microdirect.co.uk/(2180 [...] nergy.aspx

Because the production of the B3 version was stopped and was replaced by the G0 version. There's not much supply of the B3 version, so price goes up.