Q9650 is max. Bios update should be done BEFORE trying to change cpu.
750 TI only fits in the TOWER and Only After Cutting the Bracket off and ONLY with Short cards with 1 fan aka 8.4 inches max.
There are Very few single slot cards. If one was put in they hacked the bracket in half or removed bracket altogether. If you remove the bracket on EVGA models you can use tin snips to CUT OFF half the bracket. The cooling vents are blocked so you might also have to drill holes in the case to let air out. Long Cards with 2 fans DO NOT FIT and WILL NOT EVER FIT into the Tower or any other size.
Only Short cards with Short fans Fit.