Do not overclock your computer! That is the dumbest thing I've ever heard anybody dough!(hard mode: watch the whole thing without throwing your monitor out of the Window)
Back on topic, what power supply do you have and what cooling do you have? You probably already know this, but heat and power usage increase dramatically when you OC and you don't want to overclock your processor and get a fireworks display because your fan wasn't strong enough or your power supply wasn't up to the job.
In any case, I think you're better off upgrading. It isn't worth messing around with such an outdated processor when you could buy something vastly superior for a low price. OCing a mono-core Sempron is a lot like polishing the proverbial turd: you're making it better, but it's still sh*t.
personally i try not to buy intel , there stuff is just way to much money for its proformance above amd's chips
i looked at the numbers and for nearly half the price yyou can get an AM3 system that performs at 90% of what the i7s do.
Let's make a distinction here between value for money and price/performance ratio. A lot of people talk about them as if they were the same thing, but they are very different.
Imagine someone makes the best processor in the world, better than the ones they have in supercomputers, and sells it for $1000. The price/performance ratio would be amazing; it would be far better than that of any other processor on the market. But it would still be bad value for money for most people. Why? Because most people don't need much processing power. For them, this processor would be no more useful than a C2D and a lot more expensive.
This is the difference between Intel's mid-high processors and AMD's. i7s blow Phenom IIs out of the water. So do i5s and even some higher-end Core2s. Their price/performance ratio isn't that bad. However, 99% of people don't need anywhere near half the power that you can get from the lower-end i7s, so they're not necessarily good value for money. Pyrozen, you said that AMD's processors will do 90% of what the i7 will do. That isn't true. What is true is that unless you decide to start doing heavy work on your PC (playing Crysis is not heavy work
) then the benefits of an i7 won't be worth the cost.
AMD and Intel are both roughly equal value for money when one disregards the extreme ends of the spectrum. The difference is that Intel caters to the higher end whereas AMD caters to the average Joe. Intel is what Macfags think Apple is: high performance at an appropriate price.