Are you talking about SH3
? I run it without any problems on a AMD Athlon XP 2000+ with 1.6GHz, ATI Radeon8600 and 1Gb RAM. It runs very fine, the only things I am concerned with are relatively long loading times and I had to cut down most of the harbour traffic from GWX to make it run smoothly in harbours.
That your CPU is called insufficient may just be a problem with it's 64 bit registers. This shouldn't bother you.
And even IF your CPU wasn't sufficient for SH3, the same programm said that my 1.6GHz wouldn't be enough for the SH3 recommendations but I get constant framerates about 50fps. And if your not playing a 3D shooter, this is way enough
.