One cannot ask for a comparison of products to determine the "better" one without specifying which products need be compared. So all I can assume is that your question is one of two things:
1. Which brand of CPUs is best.
2. Which CPU is best.
AMD and Intel are the market leaders in making CPUs. Simply put, Intel processors tend to have better performance and produce less heat, while AMD processors tend to be less expensive.
The question of which CPU itself is best is very difficult, depending on what aspects you are looking at.
According to cpubenchmark.net, the Intel Xeon X5472, a dual core processor at 3 GHz, performs the best of any CPU tested. However, this processor is extremely expensive at about $1500 USD.
An AMD processor down the line, the Athlon FX-74, ranks in about a third of the Xeon, yet its price is still over $300.
There is an Intel Core 2 Duo E8400, as well, which ranks below the AMD (but still very highly) at a more reasonable price of a little under $200.
Lower still, the Intel Pentium E2220 is undder $100.
For even less expensive CPUs, AMD processors may still bring a high GHz level (yet with other slower and hotter-running factors). For example, the Amd AM2 U-atx 8XAGP motherboard/cpu combo is just $50.
It's better to have the Quad Core 2.4 GHz CPU because most games nowadays support multi-core processors.
It is generally better to have a low CPU usage, as this indicates that your computer is not overly taxed and can better handle tasks efficiently. A high CPU usage can lead to slow performance, overheating, and reduced battery life.
Not necessarily. You get what you pay for.
After about 3-4 years. You may not want to replace the CPU of your computer more than once. It is better to buy a new system after you have replaced the CPU once.
The CPU runs everything, It's the brain of the whole computer. Usually, having a better/worse CPU will make your computer run faster or slower. Hope this helped!
You do many battles against level 9 cpu's.
If money is no concern, start by upgrading CPU. It helps more when running games with alot of data, but definately more to graphics card next
Intel CPU processors have a very stable price, they don't differ a lot from the CPU processors of AMD but AMD has more discount offers on it's CPU processors which in some occassions give them a better cost to performance ratio. In other words, buying an AMD processor with a good discount might just beat the Intel CPU processor cost to performance ratio.
It is probably better to stick with the same manufacturer.
I think the CPU does a better job
If the CPU is overclocked, reducing the overclocking will help the heat. Also be sure that your case is properly ventilated and air is flowing proprtly. Otherwise you may want to replace the CPU fan and thermal grease. The better the fan and CPU fit together, the better the heat transfer. You will also want to clean or replace the other systems fans because if all the air in the case is hot, it doesn't matter how good the CPU fan is.
Not really, if you have a cpu with 1 core and 3ghz vs a multi core with 2.6ghz, the multi core is much better, it can handle more stuff and do it quicker, more cache also helps determine performance.