ASUS EAH3870 TOP: Design and Specifications
Although belonging to the TOP series, this model of the EAH3870 is a copy of the reference card with a standard cooler. The difference boils down to the stickers: “Company of Heroes: Opposing Fronts” on the cooler casing and “ASUS” on the fan:
As we noted in our earlier review, the PCB of the ATI Radeon HD 3870 is much simpler than the one of the Radeon HD 2900 XT. There is nothing wrong about it considering the 256-bit memory bus and the more economical RV670 chip of the newer card. The simple two-phase GPU power circuit is governed by a uPI uP6201AQ controller. A uPI uP6101BSA controller is responsible for the memory chips. Manufactured on 55nm tech process, the RV670 chip is indeed very economical and RV670-based cards are satisfied with a single 6-pin PCI Express 1.0 power connector.
The ASUS EAH3870 TOP carries the same memory as the reference card, Samsung K4U52324QE-BC08. These 512Mb chips work at a voltage of 1.8V and have a rated frequency of 1200 (2400) MHz. ASUS didn’t overclock them much, though. The memory is clocked at 1143 (2286) MHz, which is just a little higher than the reference memory frequency of 1125 (2250) MHz. So we can’t expect great benefits from this side. The card offers a total of 512 megabytes of graphics memory although the official website mentions it as EAH3870 TOP/G/HTDI/256М. This must be a type and the card’s name should instead have “512M” at the end.
The GPU frequency is increased far above the reference card’s 775MHz to 851MHz. This can hardly add more than 5-10% to the frame rate. The maximum we can expect is 15% but ASUS only promises a 4% performance growth. The GPU has a standard configuration with 64 universal shader blocks with 5 ALUs in each, 4 texture processors, and 4 rasterization processors. In other terms, the GPU can be said to have 320 streamed processors, 16 TMUs and 16 ROPs. As we noted in our reviews, the Radeon HD architecture is unrivalled in its computational capacity, and the number of ROPs is not a bottleneck in modern games. It is the amount of TMUs that can have a negative effect on performance which can be further aggravated by insufficiently deep application-specific optimizations in the driver.
Like any Radeon HD 3870 with the reference design, the ASUS card supports CrossFireX subsystems built out of two to four graphics cards. The card is equipped with two dual-link DVI-I ports and supports the audio-over-HDMI feature by means of an included adapter. It can also output analog video in Composite, S-Video and YPbPr format via its 7-pin mini-DIN connector.
The ASUS EAH3870 TOP is cooled with a reference cooler developed by AMD for this card specifically and described in our review of the new series. It resembles the cooler of the Radeon X1950 XTX but has a different and simple design actually. The cooler is based around a heatsink milled out of a whole chunk of copper. The monolithic heatsink minimizes thermal resistance for higher cooling performance without heat pipes.
The heatsink is cooled by a 75mm blower like the one employed in the cooler of the Radeon X1950 XTX. The hot air is exhausted out of the system case through the slits in the card’s mounting bracket. The load-bearing transistors of the power circuit and the memory chips are cooled with individual heatsinks, the memory heatsink being made from copper, too. Thanks to low heat dissipation of the RV670 even when clocked at 850MHz the fan works at a low speed and the cooler is almost silent. Its only drawback is the dual-slot form-factor, but it has already become standard for high-performance graphics cards and its clumsiness is made up for by its ability to exhaust the hot air out of the PC case which is not possible with single-slot coolers.