Note: I'm even comparing the 2.33GHz C2D to the latest and greatest, since the 1.8GHz one isn't listed.
While you probably don't need to upgrade your CPU, I don't see how your CPU can be only 20% slower than the latest and greatest. > yet according to all the benchmarks I've seen by Anntech, Tom's Hardware and others, my performance results are less then 20 percent below the latest/greatest CPU's. > My current system is a C2D 1.8GHz E6300 that's now pushing 4 years of age, I have a quad core, but often have to wait for the hard drive to do anything. Yes, each core has overhead, but in general, more cores does increase the system's potential performance even if it maintains or decreases an application's performance. Imagine a single-threaded game with a high CPU demand that consumes all time on a single CPU, while background processes such as the OS, drivers, pr0n downloads, etc. There's also cpu (hardware)-level overhead to consider, and the possibility that caches aren't ramped to the same level, so now more cores may be sharing a same-sized cache. Now add more OS overhead to that cpu for core management. It is running as fast as possible, with only OS overhead getting in the way of using 100% of that cpu. Imagine a task running on an otherwise idle core. So all single-threaded tasks get slower as the number of cores rises. The 6 core system is slower in non-parallel tasks because the OS has per-core overhead. You notice too, using a multi-core, multi-threaded system. It allows for more things to happen at the same time, from an OS perspective, and lowers overhead. In a desktop the tasks are more intense so it is less useful to have lots of threads/CPU (currently 2 is the highest in the Core i3/5/7 series) but more cores are still quite useful. The more than can run side-by-side from the OSes perspective, the less overhead and the more efficient use of processor resources. The tasks it normally deals with are not high load, but they switch around a lot. Each core can handle 8 threads in hardware, meaning it acts like a 64-core CPU though only having 8 actual cores. Sun's new chips are designed with that in mind. This is the reason why web/DB heavy servers like to have lots of cores, even if less powerful. They don't switch contexts, they just keep running.
However that all goes away if instead multiple things run at the same time on hardware. If a processor is doing something, and the OS needs it to do something else, it has to generate an interrupt, push everything on to the stack, switch to the kernel, switch to the net process, etc.
Reason is what OSes really have is a heavy context switching overhead. Everything I see shows that modern OSes not only don't have an overhead with more cores, it helps things.
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