The card was installed in a system with the following specs:
- Antec P180 with fans in configuration #5: Nexus D12SL-12 soft-mounted in the back, plus a Scythe SY1225SL12L in the PSU chamber
- Seasonic X-650 PSU
- i7-870 CPU with Scythe Mugen-2 heatsink and stock fan
- one SSD; and in the PSU chamber two WD Red 3TB, and a Seagate 7200RPM 2TB
- an outgoing ATI HD 5850 with Arctic Cooling Accelero S1 and Scythe SY1225SL12L
Back to the GTX 970: when it was first installed, the fans ramped up to 100% then down to about 50%. After installing the Geforce drivers they lowered to 34%, or 1600 RPM. Neither Gigabyte's OC Guru II software nor MSI Afterburner could convince the fans to spin any slower. At this speed the graphics card fans are the most prominent noise source, but I can still hear the monitor and Seagate drive. The noise is not distracting when music, games, or movies are played, but can be heard during breaks in the sound. The fans mostly sound like a tonal whoosh, but I can hear some pulsing, probably due to the three fans running at slightly different speeds. I may have also heard some electronics interference in the headphone output, but too be fair I heard it with the old video card too--the Asus Xonar D1 sound card has been a real disappointment in this regard (and many others).
So, out-of-the-box, I cannot recommend this card to someone who wants a quiet computer. But I intend to try several things to lower the noise:
- I've asked Gigabyte support how I can turn off the fans at low temperature. MSI and Asus have GTX 970 models that do this, and I heard that EVGA is developing a BIOS update to allow the same. So maybe Gigabyte will follow suit.
- I may try to install a Zalman Fanmate. X-bit labs says the Windforce fans can run as low as 3 volts, or 1000 RPM.
- More likely, I will remove the stock fan shroud and tie a quiet 120mm fan (or two) to the heatsink.
- Finally, I might install another aftermarket heatsink, such as the Prolimatech MK-26.
I took some power measurements done by eyeballing a Watt's Up power meter that measures whole system AC consumption. Load measurement was taken while running the Bioshock Infinite benchmark at 1080p, Ultra + DDOF graphical settings. Additional measurements were taken with GPU-Z.
HD 5850:
Idle: 95-100W
Load: 210?-235W
FPS: 29.4
GTX 970:
Idle: 85-90W
Load: 225-285W
FPS: 94.4
Frequency: 1367MHz
Voltage: 1.225V
Peak TDP: 66%
The GTX 970 responded well to forced TDP throttling. I lowered the TDP limit to 40% using OC Guru II and re-ran the benchmark:
Load: 215-225W
FPS: 81.0
Frequency: 900-1367MHz
Voltage: 1.03-1.225V
Peak TDP: 42%
I'm rather CPU-limited, so someone with a more modern processor might see a bigger performance drop. I may test again with supersampling antialiasing, to more fully load the card.
In conclusion, I think the GTX 970 is an okay GPU for quiet gaming. It has an FPS/watt ratio higher than anything else bar the GTX 980. However it is difficult to cool silently, and it may be wiser to wait a month or two for a GTX 960 / 960 Ti with lower TDP, or wait longer for Nvidia to produce 20nm parts.
Either way, Gigabyte's card is probably not the best one to get if you want a near-silent PC.