So it's been a while. Picking up on this project, the next step was to cut the hole for the GPU intake fan.
After some deliberation I decided against crudely cutting a hole myself with a handheld drill and hole saw. Too much risk of damaging the beautiful finish or warping the panel. Instead of ruining it, it made sense to take this to be professionally CNC cut.
I'm very glad I did...
Money well spent. There is just no way I could have done this myself and achieved this level of accuracy and quality.
Now for the fans. Option #1 is usage of a 92mm axial fan, Arctic F9 as a mockup here:
Option #2 is use of the AC Infinity 120mm radial blower fan:
Using the 120mm blower fan will require trimming part of the heatsink, because there is only about 100mm of room, so I re-assembled the build to test the performance of the axial fan first.
On to the performance tests!
Test Configuration
For performance testing below, I evaluated the maximum performance at different voltage levels and the level of fans needed to keep temperatures in check. If the GPU reached 80C or CPU reached 75C during the test, it's considered a failure. Here is the breakdown on what exactly each level means, in terms of the fan RPM and noise:
"Silent" < ~20db (Estimate)
50mm GPU Exit Fans x4 (CHA header, Speedfan controlled): up to 40% speed, <2000 rpm
50mm CPU Exit Fans x2 (CPU header, Speedfan controlled): up to 40% speed, <2000 rpm
92mm Axial Intake Fan x1 (GPU header, Afterburner fan curve): up to 30% speed, <1000 rpm
"Audible" < ~30db (Estimate)
50mm GPU Exit Fans x4 (CHA header, Speedfan controlled): up to 60% speed, <3000 rpm
50mm CPU Exit Fans x2 (CPU header, Speedfan controlled): up to 60% speed, <3000 rpm
92mm Axial Intake Fan x1 (GPU header, Afterburner fan curve): up to 40% speed, <1300 rpm
"Max" > ~30db (Estimate)
50mm GPU Exit Fans x4 (CHA header, Speedfan controlled): up to 80% speed, >3000 rpm
50mm CPU Exit Fans x2 (CPU header, Speedfan controlled): up to 80% speed, >3000 rpm
92mm Axial Intake x1 (GPU header, Afterburner fan curve): up to 100% speed, >1900 rpm
Test results
Unigine Heaven Extreme @ .800mv (~1800mhz)
Silent: Pass
Audible: N/A
Max: N/A
Conclusion: Silent
Unigine Heaven Extreme @ .900mv (~1900mhz)
Silent: Fail
Audible: Pass
Max: N/A
Conclusion: Audible
Unigine Heaven Extreme @ 1000mv (~2025mhz)
Silent: Fail
Audible: Fail
Max: Pass
Conclusion: Max fans
Witcher 3, Ultra settings @ 1000mv (~2025mhz)
Silent: Fail
Audible: Pass
Max: N/A
Conclusion: Audible
Stalker: Call of Pripyat w/Graphics mods, Ultra quality @ 1000mv (~2025mhz)
Silent: Fail
Audible: Pass
Max: N/A
Conclusion: Audible
Summary
With the addition of the GPU intake fan, the rig is able to dissipate enough heat to achieve a silent gaming system at a decent level of boost. It remains to be seen if it will be possible to maintain maximum boost in all games while still having a silent profile. This won't be known until the blower fan is tested in my next post, because I estimate that the blower fan will be much more effective than the axial fan. Additionally I plan to add ducts to channel the airflow for further improvement.
In the two games I tested, real gaming performance turned out to be not as demanding as the Unigine synthetic stress test. Unigine just hammered the GPU Load% and power limit to maximum the entire time. In real tests though such as the Witcher, the engine is apparently limited to 60FPS and I observed the GPU getting some "rest" so to say on less demanding scenes, with the voltage dropping down in the .8v range when not needed. This reduced the fan requirements quite well and means this game could be run with high boost speeds.
Stalker COP does not have a FPS limiter like Witcher 3, and voltage was pinned at 1.0v the entire time. Still, it appeared to generate less heat than Unigine, and the boost speeds could still be maintained fairly high, if not quite as high as the Witcher.
So next, I will try out the blower fan and see if performance is improved further.