In terms of overall gaming performance, the AMD Opteron 6320 is noticeably better than the AMD Opteron 4274 HE 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.

The Opteron 6320 was released less than a year after the Opteron 4274 HE, and so they are likely to have similar levels of support, and similarly optimized performance when running the latest games.

Both CPUs exhibit very powerful performance, so it probably isn't worth upgrading from one to the other, as both are capable of running even the most demanding games at the highest settings (assuming they are accompanied by equivalently powerful GPUs).

The Opteron 4274 HE and the Opteron 6320 both have 8 cores. Games are not yet able to harness this many cores, so it is probably excessive if you mean to just run the latest games; however, if you intend on running a server with this CPU, it would seem to be a decent choice.

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 Opteron 4274 HE and Opteron 6320 are not from the same family of CPUs, so their clock speeds are by no means directly comparable. Bear in mind, then, that while the Opteron 6320 has a 0.3 GHz faster frequency, this is not always an indicator that it will be superior in performance, despite frequency being crucial when trying to avoid GPU bottlenecking. As such, we need to look elsewhere for more reliable comparisons.

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 Opteron 4274 HE and the Opteron 6320 have the same L2 cache size, but the Opteron 6320 has a 16376 MB bigger L3 cache, so in this area, it wins out over the Opteron 4274 HE.

The System Bus Speed is important for providing higher bandwidth, and with higher bandwidth the system has the capacity to move more data over a certain time period than it would with lower bandwidth.

The Opteron 6320 has a 3200 MHz faster System Bus Speed than the Opteron 4274 HE, and as such, has a massively higher limit when it comes to the size of the data being processed at once.

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.

The Opteron 4274 HE has a 50 Watt lower Maximum TDP than the Opteron 6320 (though they were created with the same size 32 nm manufacturing technology). What this means is the Opteron 4274 HE will consume significantly less power and consequently produce less heat, enabling more prolonged computational tasks with fewer adverse effects. This will lower your yearly electricity bill significantly, as well as prevent you from having to invest in extra cooling mechanisms (unless you overclock).