it will work fine electrically. It is a very tight fit along the top and will slightly interfere with the top connector mounts.
do you own this already? If not I think there are better choices for the XPS 8700. for starters, 850W well above the needs of any Single GPU you might add.
Also, are you refering to the RM or the RMx ? I'm not an expert on the Corsair PSUs but I seem to remember the RM series was just OK, and there are many better PSUs on the market for the same or less money. Better in terms of better / cleaner power or more efficient or quieter, or better cables etc.
Hi thanks for an answer no i was thinking to buy it. Just bought new gpu asus gtx 750i and thinking to change case for Corsair Graphite 230T.
you do not need a new PSU for a GTX 750ti. Unless you get up to a GTX 770 or higher 7x0 series, or a gtx 970 or higher 9x0 series the stock PSU is fine.