The AMD rig in my spec below processes 8.2 gb/sec in memory bandwidth, that tops the chart in Everest and it's the fastest rig I've ever seen, I know there are plenty of faster (in some respects) PC's out there, but the AMD cpu is not the cause of your woes.
AMD and Intel both make a large range of CPU's with a wide range of power. It's up to you to do the research and choose the correct components for your PC, but like so many people, you haven't got the time or the knowledge to do that, so you just went and bought a Gateway with a XXXX cpu which sounded good.
Did it occur to you why the Gateway was cheap and attractively priced? It's because they use cheap mainboards, cheap ram, cheaper cpu's, cheaper everything! It's not just gateway, it's all the big PC dealers. I say dealers, because they don't make the components, they buy them, from the cheapest suppliers.
Until you understand what a chipset is and you start building your PC based on that knowledge, bagging this manufacturer or that one will do no more than blow off frustrations.
If I were a betting man, I'd lay money that your problems are not even hardware related, but instead related to software and bios, and I'd lay 10:1 odds as well, because over 95% of PC problems are simply caused from the operators filling the PC up with garbage software (unwittingly) until it no longer runs at all.
Some current flight sims seem to fit this category

PS. There is a paradox in your signature

My signature contains one as well, but mine is hardware related......