Here’s a refutation of the theory that NVIDIA’s partners receive all GeForce 7 series cards ready-made. Although the ASUS Extreme N7800GT uses the reference PCB design, its PCB is colored blue rather than traditional red.
The graphics card doesn’t have an NVIDIA logo, carrying ASUS’ ones instead. It means that the GeForce 7800 GT may come to graphics card makers as a GPU + memory kit, and it’s up to the manufacturer to choose the color of the lacquer, to put any logos on it and to mount an appropriate cooling system. ASUSTeK Computer took the opportunity to deflect from NVIDIA’s reference model, as you can see. According to the manufacturer’s website, this graphics card exists in two versions, a reference one and the one we are dealing with now. They are called Original Edition and ASUS Blue LED Edition, respectively.
The ASUS Extreme N7800GT strongly resembles ASUS’ V9999 Gamer Edition card we described in our earlier article (for details see our article called ASUS V9999 Gamer Edition Graphics Card Review ), largely due to the same cooling system. The system is a mixture of the reference coolers from GeForce 6800 Ultra and GeForce 6800. The former contributed the memory chips heatsink and the latter, the low-profile design. ASUS also added a few touches of its own: they replaced the material of the fan and of the cooler’s casing with blue translucent plastic that reacts to ultraviolet light, embellished the casing with an ASUS logo and installed bright blue LED highlighting. Well, beauty has nothing to do with functionality, yet this cooling system should surpass the reference GeForce 7800 GT cooler in efficiency and noise characteristics, too. First, it uses an all-copper heatsink which directly contacts with the GPU and, second, ASUS’ blower is less noisy than the one employed in the reference cooler.
High-efficiency thermal paste is used as thermal interface between the heatsink’s sole (which might have been polished better, by the way) and the GPU die. The memory touches the cooler through cloth pads soaked in thermal paste. This solution is quite efficient, we should say. The fan is attached via a two-wire cable, meaning the lack of smooth speed adjustment as was implemented on the ASUS V9999 Gamer Edition. And still, you can control the speed of the fan. The latest version of RivaTuner allows you to set up different speeds for 2D, Low Power 3D and Performance 3D modes.
A curious design detail is a metal plate that goes along the top edge of the PCB and prevents it from bending. This plate was present on the ASUS Extreme N7800GTX TOP where it was obligatory because of the massive cooling system installed on that card. Here, however, it is hardly really necessary and is nothing else but a decoration element. There’s a cut in the plate near the MIO connector so that nothing hindered you in attaching a SLI connector.
The graphics card employs Infineon HYB18T256324F-20 chips of GDDR3 memory with 256Mb capacity, 2.0V voltage, and 2.0ns access time. The memory is clocked at its rated frequency, i.e. at 500 (1000) MHz. The GPU is clocked at 400MHz (the default frequency of the GeForce 7800 GT). We want to remind you that this clock rate refers to the GPU’s pixel processors and raster operators only. Its vertex processors are clocked at 440MHz.
As mentioned above, the graphics card is VIVO-compatible by using a Philips SAA7115HL controller equipped with two 9-bit analog-to-digital converters and capable of hardware scaling of the captured image. This chip is installed on all GeForce 7 series cards, endowing them with additional functions.