Difference between a Geforce 840M and a GT 840M?

[Jordan Gonzalez]

Going to buy a laptop soon and saw two different models of it, i noticed that one had a Geforce 840M and the other had a Geforce GT 840M. So i was wondering whats the difference between the two and which one would be better for gaming?

laptops
840M
http://www.amazon.com/dp/B00R45UFUY/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=2SE7NGVDZQLE5&coliid=I7TU95RLGCW7J
GT 840M
http://www.newegg.com/Product/Product.aspx?Item=N82E16834314807&cm_re=Acer_Aspire_V_15_V3-_-34-314-807-_-Product

 

[RobWHS]

http://www.tomshardware.co.uk/answers/id-2295330/840m-2gb-840m-4gb.html

 

[velo3100]

The gpu is the same.