upgrade dell xps 1710 motherboard

You'll need a new case; your old case and board is btx format, which isn't made for i5 or i7 cpus; I recommend this one:

http://www.newegg.com/Product/Product.aspx?Item=N82E16811139018 $50 after rebate
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130706 $110 socket 1150 for new haswell cpus
http://www.newegg.com/Product/Product.aspx?Item=N82E16819116897 $200 4570s haswell 65w quad core.

You may be able to reuse your old dell power supply; if not, then this one is adequate:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139027 $30 after promo code and rebate; must register with newegg for promo code to work