Devil's Canyon Overclocking
Intel targets its Devil’s Canyon processors at enthusiasts, so the new CPUs both have unlocked frequency multipliers which allow to overclock the processor, bus, memory and graphics core independently. Well, that's in fact the same functionality we had with the previous Haswell K series models.
Haswell processors with unlocked multipliers used to be rather neglected by overclockers due to their high temperature. The typical top frequency was limited to 4.3-4.5 GHz as the consequence. The Devil’s Canyon series, on the contrary, is promoted as optimized specifically in terms of cooling. Being less hot, the new CPUs are promised to conquer higher clock rates without replacing the internal thermal interface.
Practical tests performed right after the Devil’s Canyon release didn't show anything special, though. We didn't even review engineering samples of the new processors because they were no better than their predecessors. But now we've got off-the-shelf samples – and they are no different, either!
First we took the junior quad-core i5-4690K and reached a conventional 4.4 GHz with it. It is the maximum frequency our sample can work continuously at in a typical desktop PC. We don’t try to set any overclocking records, so we limit ourselves to a dual-tower Noctua NH-D15 air cooler, one of the most efficient in its class.
To ensure stability during our tests, we had to increase the voltage to 1.15 volts. We had no issues at such settings but the hottest CPU core would reach a temperature of 98°C when running LinX 0.6.5, which was very close to the 100°C threshold. Thus, overclocking an i5-4690K is limited by overheat which is caused by the low efficiency of the internal thermal interface. You can hardly cope with this problem by using a higher-performance air cooler.
The overclocking results are poor because you can only change the voltage in a very narrow range. The best we could achieve with our i5-4690K - 4.4 GHz - is no better than the typical results of the i5-4670K released over a year ago. It also equals the specified clock rate of the i7-4790K in Turbo mode.
Is the flagship model better, perhaps? Well, it is almost the same. The maximum clock rate we reached was 4.5 GHz. And we had to increase the voltage to 1.2 volts to avoid BSODs. The temperature of the hottest CPU core was up to 96°C at such settings in LinX 0.6.5.
So we cannot expect better overclocking even with high-performance air coolers just because the internal thermal interface limits your voltage adjustment range. The 32nm Sandy Bridge processors could work at a voltage of 1.4 or 1.5 volts with a high-efficiency air cooler. The Haswell and Devil’s Canyon models, on their part, are manufactured on 22nm tech process but can only work at 1.2 volts without overheating. This is a clear indication of the low quality of the thermal interface.
Unfortunately, the Devil’s Canyon series has the same overclocking-related problems as the Haswell. The temperature of the CPU cores rises up quickly and high as soon as you launch a heavy application and it takes some effort to keep it within an acceptable range. The new LGA1150 models turn out to be no better than their overclocker-friendly Haswell predecessors at ordinary overclocking. The new thermal interface doesn’t help. We can only hope that the next breed of LGA1150 products for enthusiasts will use fluxless indium-based soldering of the semiconductor die to the processor cap. Right now, only the recently released Haswell-E processors use soldering but they cost much more than the Devil’s Canyon series.