Several people have messaged us asking why we chose a quad-core CPU for our test rig when there are processors with hex-core, octo-core, or even higher-base cores available, along with the option of dual-processor motherboards.
In short: the Intel Core i7 6700K Skylake 4.0 GHz quad-core is one of the best value high-end processors on today’s market, and beyond that, one of the top processors at any price for a personal computer.
Having multiple cores in a processor is great. What multiple cores do is allow the computer to multitask. Each core is a separate instruction that can be completed at once. The more, the merrier… to an extent. Many programs are not optimized to take full advantage of these extra cores, and this is especially true for core counts above four. Games and graphics editing software typically lean more on a single core at once as the tasks they demand of the CPU tend to be singular large ones. Where having a large number of extra cores really shines is in typical small business server use. Server workloads for businesses often involve a large number of small tasks needing to be performed at once. We are not saying that gaming and graphics use do not utilize extra cores, but that a high performance per core is more desirable than a high core count. The 4.0 GHz in each core of the i7 6700K leads the market in performance and can handle heavy loads whether or not the software is not multi-core optimized.
While comparably priced true hex-core and octo-core processors do perform faster with all cores running at maximum capacity, for single-core use they lag significantly behind. An octo-core processor priced equally to the i7 6700K has about half the frequency per core: which means half the performance. To get single-core performance as high as our chosen processor from a hex-core or octo-core processor requires exponentially increasing the price of the CPU. This puts the builds beyond what most clients deem a reasonable price.
Furthermore, we feel that hex-cores and octo-cores are still too bleeding edge to be cost-effective for the typical client. Buying bleeding edge equipment often results in a person having hardware that is not yet fully matured. This means later generations of that technology appear quickly afterward which rapidly improve upon it in performance and cost. A similar concept can be seen with the first quad-core processors, which were hugely more expensive than the dual-core processors of the time—but within a short time they were eclipsed by newer quad-core processors that were not only more powerful but were also less expensive.
We did consider a dual-processor motherboard running two i7 6700Ks in tandem. We decided against it for a few reasons. The most important was that it would increase the total cost of the system by 150%. Most builds we have tested with the i7 6700K were not bottlenecking with the processor, so spending a lot of money to improve it was an inefficient way of improving the speed of the computer. Finally, at this point most of our clients have not needed that extra processing power. We wanted our primary test rig to best represent the most typical type of personal workstation, gaming rig, or graphics editing system we design. We felt it would give us better test data than a rig that spares no expense in the pursuit of maximum speed and performance. Meanwhile, a dedicated server test build is slated for later development.
It’s worth mentioning here that the i7 series of Intel processors does have a special feature called hyperthreading that works as a pseudo-dual core capability for each core. This does not actually double the number of cores. It is a method of managing incoming tasks more efficiently, that boosts performance from 20-30% above what could otherwise be expected from the processor.
An important feature we took note of with the i7-6700K is the comparatively low-wattage requirement. This allows our power supply to be allocated to other components, such as the GPU, without requiring an overly large PSU. Increasing the PSU size would generate more heat, restrict airflow, and cost more.
The i7-6700K’s 4.2GHz overclock speed will be appealing to certain clients. However, we have not yet done tests on overclocking the processor, and do NOT recommend overclocking for non-expert users nor support its use in our builds.
As far as choosing between Intel vs AMD, we have more experience with Intel processors and appreciate their versatility. We’ve talked about single-core vs multi-core strength. Using an Intel processor doubles down on that with Intel processors having stronger single-core performance than AMD processors. AMD processors typically contain more cores than their comparatively priced Intel competition, which we find to make them a fantastic choice for our clients’ servers, but less optimal for single-user machines. Intel’s integrated graphics and on-board video decoding capability are welcome additions to their processor. For the base test machine the i7-6700K is our first choice; however, we have an AMD Phenom II X4 975BE on our testing schedule to get a side by side comparison in the near future. Stay tuned!