La carte
ASUS decided to equip the GeForce GTX 980 Ti STRIX with a new version
of their famous DirectCU cooler. This is actually the third version of it and they decided to come up with a triple fan cooler. In the case of this card you get no less than
five heatpipes, one measures six millimeter, two measure eight millimeter and two offer massive ten millimeter diameter. As with the DirectCU II cooler there is no base plate. ASUS actually communicates, that this should help decreasing temperatures even further, since there are less heat transfers. If you have a very close look at the heatpipes, you notice that there are rather large gaps inbetween the pipes. These gaps need to be filled with enough thermal compound. Apart from that this has has uneven cooling as a result, since the layer of thermal compound in the gaps is much thicker than between the GPU and the heatpipe. This actually leads to the point that cooling is not provided to the GPU uniformly, when there is the so called "Direct Touch" approach in place. Apparently this is nothing to worry about, but in countless cooler reviews we noticed, that models with a copper baseplate perform better than others with Direct Touch Heatpipes.
Soldered to the heatpipes you find the fin stack which is being
provided with fresh air by three fans, which are being manufactured by Everflow. The fans on the new STRIX Gaming series cards are designed to spin only when the GPU temeprature reaches 65 degrees, which means that in 2D mode they are completeley off. Also, under low loads the fans don't start to spin. Under high-load the noise level is still silent, subjectively
speaking.
The ASUS GTX 980 Ti STRIX Gaming graphics card, or to be precise our sample of
it, allowed a maximum stable overclock of 1'539 MHz
for the GPU and 1'825 MHz on the memory side. We used Furemark V1.11.0 Geeks3D
benchmark with 15 minutes duration. With these clocks we had to feed the GPU
with 1.243 Volts and the memory ran at stock voltages.
A closer look at the PCB shows that ASUS equipped this card with a
12+2+1 phase digital power design. The GPU gets its current from twelve phases, two phases take good care of the 6GB of GDDR5 memory and on additional phase is in charge of PLL. Once more, ASUS is using high quality super alloy chokes. Apart from that it's the first time that ASUS has a fully automated production process in place. This means, that the human error can be completely removed from the production line and the individual parts are being mounted on the PCB in always the same, perctly uniform manner.
Checking the voltage regulation chip, we find a digital multi-phase buck
controller ASP1500U. Apart from that there is uP1641P, which is taking care of voltage regulation for the memory chips.
The memory chips used are made by SKHynix and carry the model number
H5G04H24MFR. They are specified to run at 1'750 MHz (7'000 MHz
effective)