Slow is a relative term. I am sure that PC is blazing fast compared to a 4 year old dell dimension but probably not as fast as an i7.
Overall though it looks like a fairly strong build, should be able to handle most games at high to medium high settings at 16x10 res. If you used the PSU that comes with that raidmax case you should swap it out for a better one. Raidmax PSU's blow. As in blow up.