PCB Design and Specifications
As opposed to the Palit GeForce GTX 470 described in our previous review, the Zotac GeForce GTX 480 AMP! is a copy of the reference card equipped with a nonstandard cooler. The PCB is long and may press against the HDD rack in some system cases.
The cooling system is developed by the world-famous Zalman. The VF3000 cooler is designed for today’s top-end graphics cards. Running a little ahead, we must acknowledge that it copes with its job excellently, yet is not absolutely free from downsides. Here is how the Zotac card looks with its cooler removed:
The additional heatsink takes the heat off the memory chips and the voltage regulator components but may provoke some problems if you want to remove the main heatsink: when you try to undo the screws on the reverse side of the PCB, the poles the heat-exchanger stands on turn around together with the screws. We don’t think that ordinary users will ever have to do that, though.
The Zotac card is no different from the reference sample in components as it uses the same PCB. The 6-phase GPU voltage regulator is managed by a CHL8266 chip from CHiL Semiconductor. MSI Afterburner allows changing the GPU voltage but you must be aware that software-based volt modding is just as dangerous as hardware modifications. The 2-phase memory voltage regulator is controlled by an uP6210 chip from uPI Semiconductor. The card is powered through one 6-pin and one 8-pin connector, like the competing flagship Radeon HD 5970. The 8-pin power connector is indeed called for as its load is quite high.
There are 12 Samsung K4G10325FE-HC0 memory chips under the auxiliary heatsink. They have a combined capacity of 1536 megabytes. The memory frequency is increased above the reference card’s to 950 (3800) MHz, which is still not really high for memory chips that can be clocked at much higher frequencies. Coupled with the 384-bit memory bus, this frequency ensures a peak bandwidth of 182.4 GBps. This is a good but not record-breaking level. The Zotac GeForce GTX 480 AMP! won’t feel a lack of memory bandwidth. Like the rest of GeForce GTX 480 models, the card can automatically lower its memory frequency to 67 (270) MHz in the power-saving mode.
This sample of the GF100 chip was manufactured on the 13th week of 2010. Its frequency is increased from the default 701/1401 MHz to 756/1512 MHz. The 15 active multiprocessors provide a total of 480 ALUs and 60 TMUs. The rasterization subsystem is made up by 48 RBEs. The GPU voltage is 1.037 volts which is much higher than that of the GeForce GTX 470, so we should not expect this card to have low power consumption and heat dissipation.
Zotac’s factory overclocking is far from impressive. The 8% GPU frequency growth may increase the frame rate somewhat in games but the difference can hardly be spotted with a naked eye, especially as this overclocking cannot improve the main downside of the GF100 architecture, the texture-mapping performance which is lower than that of the G200 processor even.
The GPU clock rates are automatically lowered to 51/101 MHz and to 405/810 MHz in the two power-saving modes: Windows applications and simple computing tasks like HD video decoding, respectively.
Like most other GeForce GTX 480 cards, this one has a couple of DVI-I ports and a mini-HDMI connector that usually calls for an adapter. There are also MIO connectors on the PCB which are especially important for us since we are going to benchmark the Zotac GeForce GTX 480 AMP! in pair with a Gigabyte GeForce GTX 480 in SLI mode.
The card’s cooling system is a separate story. As we noted above, the cooler is an OEM version of the Zalman VF3000 which can keep even the hottest of today’s single-GPU cards like GeForce GTX 480 and Radeon HD 5870 cool and running. With the casing removed, the cooler looks like this:
The heatsink ribs go in parallel to the mounting bracket, so not even a portion of the hot air will be exhausted out of the system case. This is not good considering the hot temper of the GeForce GTX 480. Besides, we found a construction defect: the screws holding the casing on the heatsink are inserted into the holes in the heatsink plates and bend them a little. This was enough for the plastic fan locks of our sample to slip out of their sockets. As a result, the mounting bracket bent a little and the left impeller began to catch on the cooler’s casing. You should check everything out for this defect if you are going to purchase this version of GeForce GTX 480 or install a Zalman VF3000 on an ordinary version of the card.
The cooler represents a simple design with a copper heat-exchanger that does not use the direct touch technology. The heat-exchanger is connected with five heat pipes to a heatsink consisting of aluminum plates. The plates are press-fitted to the pipes without any soldering or thermal glue and do not sit very tight. We easily took off a couple of outermost heatsink plates from the heat pipes of our sample of the VF3000.
The plastic frame fastened to the heatsink with locks carries two 3.6W Zalman ZE9215BSH fans connected in parallel. As you can guess, the fan has a diameter of 92 millimeters. It is even more correct to say that the fans are not installed on the frame but make up a single whole with it. As we’ve said above, this thing is fastened to the heatsink tight enough and the edge of the frame may lift up, making one of the impellers catch on the aerodynamic casing of the cooler.
It is important that the heatsink is rather tall and, together with the fans, takes up not one neighboring slot (like the reference cooler from Nvidia) but two. Thus, the Zotac GeForce GTX 480 AMP! won’t do for each system case. For example, on our ASUS P6T Deluxe mainboard this graphics card blocked both available PCI slots. So, if you are going to purchase this GeForce GTX 480, you should make sure it won’t interfere with your other expansion cards.
The cooling system of the Zotac GeForce GTX 480 AMP! seems to be efficient but it is not free from downsides such as its height and the mediocre assembly quality. We’ll check it out in practical tests in the next section.