The choice of processor:
The processor is the most important component in a flightsim PC. This part should be a priority in your choice for maximum performance.
FSX Performance: Up to more than 75% the frame rate is produced by the CPU. Quad core processors will show further improvement in frame rates and increased quality of the autogene scenery, traffic and generated weather. Intel Core i7 technology has proven to have the greatest positive impact on FSX performance. The Core i7 9xx Extreme Edition CPU performance tests with various FSX add-ons show only a few frame rate loss in case of heavy sceneries and aircraft simultaneously processed.
Over-clocking Intel i920
We used the following settings to over-clock our Core i7 920. Most of the selected voltages were necessary to successfully and reliably over-clock the processor to 3.8 and 4.0 G Hz. Speeds faster than 4.0 G Hz were not reliable on several air coolers, but we know that they can be achieved if you’re willing to spend more on cooling.
Core i7 Turbo Mode
Turbo Mode is available on all Core i7 processors; it allows the processor to accelerate one core by one or two multiplier increments (133 MHz or 266 MHz at stock speed) when fast single-thread performance is required. We left this mode enabled at the settings up to 3.33 G Hz (3.314 MHz), as it introduces a further clock speed increase of 169 MHz (equivalent to one multiplier at increased Quick Path Interconnect base clock) without requiring a voltage increase.
At 4 G Hz we observed that Intel’s over-speed protection kicked in. The primary purpose of this feature is to protect the processor from overheating at highly over-clocked settings by effectively throttling the processor speed. The feature could not be switched off with the BIOS version we used, and it kicked in when we set the system to run at 4.0 G Hz. Its activation became obvious as we observed performance that was actually not much superior to that at the 3.8 G Hz setting, and also by the system power consumption: while we initially measured a 417 W peak power, this number fell to 370 W after a few minutes of operation, showing that the CPU was throttling. CPU-Z confirmed the results.
It is typically possible to delay the overspeed protection kicking in by applying more powerful cooling products such as a liquid cooling solution. Since the focus of this article is reasonable overclocking, though, we decided to stick with the stock cooler from Intel (although it’s certainly not the best choice for serious overclocking).