In terms of overall gaming performance, the Intel Core 2 Duo E8500 3.16GHz is noticeably better than the Intel Core 2 Duo E7300 2.66GHz when it comes to running the latest games. This also means it will be less likely to bottleneck more powerful GPUs, allowing them to achieve more of their gaming performance potential.

Both the Core 2 Duo E7300 2.66GHz and the Core 2 Duo E8500 3.16GHz were released at the same time, so are likely to be quite similar.

The E7300 2.66GHz and the E8500 3.16GHz both have 2 cores, and so are quite likely to struggle with the latest games, or at least bottleneck high-end graphics cards when running them. With a decent accompanying GPU, the E7300 2.66GHz and the E8500 3.16GHz may still be able to run slightly older games fairly effectively.

Both the Intel Core 2 Duo E7300 2.66GHz and the Intel Core 2 Duo E8500 3.16GHz have the same number of threads. Both CPUs have one thread per physical core.

Multiple threads are useful for improving the performance of multi-threaded applications. Additional cores and their accompanying thread will always be beneficial for multi-threaded applications. Hyperthreading will be beneficial for applications optimized for it, but it may slow others down. For games, the number of threads is largely irrelevant, as long as you have at least 2 cores (preferably 4), and hyperthreading can sometimes even hit performance.

More important for gaming than the number of cores and threads is the clock rate. Problematically, unless the two CPUs are from the same family, this can only serve as a general guide and nothing like an exact comparison, because the clock cycles per instruction (CPI) will vary so much.

The E7300 2.66GHz and the E8500 3.16GHz are from the same family of CPUs, and thus their clock speeds are directly comparable. With this in mind, it is safe to say that with a 0.5 GHz faster base clock rate, the E8500 3.16GHz manages to provide noticeably better performance than the E7300 2.66GHz.

Aside from the clock rate, the next-most important CPU features for PC game performance are L2 and L3 cache size. Faster than RAM, the more cache available, the more data that can be stored for lightning-fast retrieval. L1 Cache is not usually an issue anymore for gaming, with most high-end CPUs eking out about the same L1 performance, and L2 is more important than L3 - but L3 is still important if you want to reach the highest levels of performance. Bear in mind that although it is better to have a larger cache, the larger it is, the higher the latency, so a balance has to be struck.

The E8500 3.16GHz has a 3072 KB bigger L2 cache than the E7300 2.66GHz, but neither of the CPUs have L3 caches, so the E8500 3.16GHz wins out in this area with its larger L2 cache.

The maximum Thermal Design Power is the power in Watts that the CPU will consume in the worst case scenario. The lithography is the semiconductor manufacturing technology being used to create the CPU - the smaller this is, the more transistors that can be fit into the CPU, and the closer the connections. For both the lithography and the TDP, it is the lower the better, because a lower number means a lower amount of power is necessary to run the CPU, and consequently a lower amount of heat is produced.

Both the E7300 2.66GHz and the E8500 3.16GHz have the same TDP of 65 Watts, and were created with the same manufacturing size of 45 nm, which means they will affect your yearly electricity bill about equally.