What's the difference between <A HREF="http://www.newegg.com/app/ViewProductDesc.asp?description=13-136-151&depa=0" target="_new"> DFI LANPARTY nF4 SLI-DR </A> and <A HREF="http://www.newegg.com/app/ViewProductDesc.asp?description=13-136-152&depa=0" target="_new"> DFI LANPARTY UT nF4 Ultra-D </A> ? SLI-DR costs $225, which is much more expensive than $147 Ultra-D, does that mean SLI-DR is better? thanks.