Testing
The test rig consists of the following parts:
Processor: Intel Core i5 2500K
Motherboard: ASUS P8P67 EVO
Video Card: SPARKLE Calibre Series X480 GeForce GTX 480
Memory: Corsair Vengence 8 GB @ 1600mhz Samsung Green low profile 30nm 8 GB @ 1600mz
Power Supply: High Power Astro PT 700w
Storage: OCZ Vertex 2 120 GB Running Windows 8 64bit
Cooling: be quiet! Dark Rock Pro 2
Case: Nanoxia Deep Silence 1
Testing was done using Intel Burn Test (IBT) with the AVX instruction set. The reason I use this instead of Prime95 with this setup is that it pushes our i5 2500K a whole lot harder, giving us a better sense of load temps. Most of the testing was done at the high memory setting for a single pass. While admittedly this in no way would qualify the chip as stable when overclocking, it gives us a realistic idea of what temps it will be hitting.
First though here are our results from the stock Intel cooler, at the stock motherboard settings, in the test rig:
Ambient temps: 22.22C/71.99F
Idle temps: 31.25C/88.25F core average
IBT temps: 78.5C/173.3F core average
After installing the cooler I started the rig up and got a CPU fan error and was forced to go into bios to resolve. For whatever reason when the fan settings are set to any of the automatic speed increases in bios, including Turbo, the fan reports as running at only ~ 540rpm. This required me to manually set the speed to a percentage. I set the fans first to 50% but felt that although very quiet, it just wasn’t moving very much air. So I went back in and set the speed to 100%. Interestingly enough it was still quite quiet, much more so than many other coolers we’ve tested at slower speeds. For this reason the fans were left at 100% for all testing.
So we ran the Dark Rock Pro 2 through the exact same test at the same motherboard settings:
Ambient temps: 17.78C/64F
Idle temps: 29.5C/85.1F core average
IBT temps: 49.75C/121.55F core average
These results are very good, but I was still wondering what would happen if we turned the cooler 90 degrees and let it blow out the back of the case. So before further testing I took the cooler off, re-applied thermal compound and reinstalled.
Here are the results with the Dark Rock Pro 2 through the exact same test at the same motherboard settings turned 90 degrees:
Ambient temps: 17.78C/64F
Idle temps: 27.5C/81.5F core average
IBT temps: 47C/116.6F core average
Turning the cooler must have allowed it to breath much more, as it gave us a load temperature average 2.75C lower. The cooler was left in this orientation for the rest of the testing as it seemed to be optimal.
I figured that we would have a pretty high overclocked ceiling with this one since it had such great stock temperatures. So we set off to see what the Dark Rock Pro 2 would do under extreme loads and clocks:
Ambient temps: 17.78C/64F
Max overclock: 4.8 ghz/1.432V vCore
IBT temps: 74C/165.2F core average
Try as I might, I just could not get the chip stable and temperatures under control higher than 4.8. The amount of voltage required to step up to 4.9 was just too much for the cooler to handle.
I was a little disappointed that we couldn’t take it any higher, but really these are first-class results considering it’s an air cooler.