Cooling System

The card’s distinguishing feature, the one that gives it the Ultimate Edition title, is the passive cooling system. We have tested a lot of graphics cards with passive coolers in our labs, but the cooler installed on the Sapphire HD 4670 Ultimate Edition has one important advantage. It is compact.

Passive coolers for graphics card are usually very large and always have a dual-slot form-factor because the heatsink has to be made large in order to effectively dissipate all the heat produced by the GPU. The heatsink usually occupies the space below the PCB, but here the developer placed it partially on the other side of the PCB.

The solution seems to be logical because the graphics slot is usually the topmost one on the mainboard. Above it there can only be a rarely used PCI Express x1. So, the empty space can be given to the heatsink. Besides, this design improves the overall efficiency of the system because the hot air from the heatsink does not accumulate below the card but rises up freely to the CPU cooler and to the back-panel system fan that will exhaust it out of the system case.

The part of the cooler located on the face side of the PCB is a heatsink with a copper base that is connected to the main heatsink with two heat pipes. We don’t find a good reason for this technical solution because the heat flow of the RV730 is rather week and might be transferred by one pipe only. Moreover, the ends of the pipes are very close to each other. In other words, the second pipe does not help distribute the heat uniformly in the heatsink, although it would do that if it pierced its top rather than side section.

The only copper elements of this system are the heat pipes and the base that contacts with the GPU die. The other elements are made from aluminum, so the total mass of the cooler is not high. The four spring-loaded screws fasten it to the PCB quite securely. There is traditional dark-gray dense thermal grease between the heat-exchanger’s sole and the graphics core. The memory chips on the face side of the PCB contact with the aluminum heatsink via elastic thermal pads.

The efficiency of this design should theoretically be high enough to cope with a Radeon HD 4670, especially if you’ve got a system fan blowing at the card from a side. Our experiment proved that point: the GPU temperature quickly grew up to 86-88 °C without a fan. But when we added a fan to blow at the card, the GPU temperature was never higher than 56 °C even during a long test session. Thus, you should follow Sapphire’s recommendation and not install this card into a poorly ventilated system case.