|EVGA GTX 460 SC Superclocked Video Card|
|Reviews - Featured Reviews: Video Cards|
|Written by Bruce Normann|
|Saturday, 04 September 2010|
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EVGA GeForce GTX460 SC (01G-P3-1372-TR) Detailed Features
With high-end video cards, the cooling system is an integral part of the performance envelope for the card. Make it run cooler, and you can make it run faster has been the byword for achieving gaming-class performance with all the latest and greatest GPUs. The EVGA GeForce GTX460 SC / 01G-P3-1372-TR uses the standard GPU cooler concept of the NVIDIA reference design, which has some distinct benefits.
Two flattened, 6mm diameter heatpipes are clamped between the thin copper mounting plate and a small aluminum heatsink, passing directly over the GPU die. Once they exit from there, they spread to the outer reaches of two semi-circular aluminum fin assemblies. Considering the power density of modern GPU devices, it makes sense to contact every square millimeter of the top surface with the heatsink if you can. The GF104 chip, like most NVIDIA GPU packages has a very large heat spreader mounted to it, and the copper mounting plate covers it completely.
The air all flows out in a radial fashion from the centrally mounted fan, and the plastic shroud contains most of it, channeling half out to the vents on the I/O bracket at the rear of the case. The other half passes over the power supply section at the rear of the card and flows out into the case. All GPUs produce a fair amount of heat, so make sure your chassis has plenty of airflow, in the right direction, in order to move hot air out of the case. This cooler design is better suited to multi-card SLI applications than some, but the cards with radial blower wheels (squirrel cages, I call ‘em...) push more than 90% of the heated air out the back of the PC case, so they are the best. EVGA is one of the few vendors that have these available for the GTX 460 product line; in fact they have several.
The GPU makes direct contact with a copper plate that is soldered to the heatpipes passing directly over the top of the GPU. The thermal interface material (TIM) was very evenly distributed by the factory, but was applied slightly thicker than necessary. One day, anxious manufacturing engineers are going to figure out that too little TIM is better than too much. For the rest of us who pay attention to these things, a thorough discussion of best practices for applying TIM is available here.
Here is a close-up of one of the tantalum capacitors on the back side of the card. They are incredibly small for the amount of charge they hold, which allows them to be placed much closer to the active components they support. This greatly improves the filtering performance at high frequencies. If you remember when ATI upgraded the HD 4870 GPU to HD 4890 status, it was the addition of small filter caps right on the GPU package substrate that allowed the 4890 to reach such high clock rates. Tantalum caps were what made that design change possible.
The main power supply controller chip used on the EVGA GTX460 SC is an NCP5388 chip from ON Semiconductor. It is a 2/3/4 Phase PWM control IC that does not supports I2C software voltage control, however the NVIDIA BIOS provides its own software control that interfaces with the controller at the hardware level. The VRM section uses a relatively simple and straightforward 3-phase design for powering the GPU. I've seen some custom GTX 460 designs recently that bump this number up to six phases, but the three provided by the reference design seem to work well, even with some serious overclocking.
The EVGA GeForce GTX460 SC uses standard Power-SO8 packaging for the Single N-Channel MOSFET power transistors and drivers in the VRM section. This discrete implementation gives up the opportunity to save a little space, but it does give the designer a broader choice in component selection, compared to a DrMOS design. The 4935N devices driving the GPU can source a whopping 93A at an ambient temp of 25C, and are downgraded to 59A at 85C. We all know how hot video cards get, so it's a good idea to have plenty of reserve current capacity for these power devices.
The memory choice for the EVGA GeForce GTX460 SC is also consistent with the NVIDIA reference designs. The basic GTX 460 specs only require 900 MHz chips for the memory, but most cards have been using these Samsung K4G10325FE-HC05 GDDR5 parts, which are designed for up to 1000 MHz. The EVGA Precision software supplied with this Superclocked edition doesn't have the capability to increase memory voltage, so don't presume that you will get much more than the rated memory speed. The 1250 MHz versions of this chip have been mediocre overclockers on the Radeon platform; we'll have to see if the lower specified parts are a little more willing to exceed their ratings.
Now that we've had the grand tour of the EVGA GTX460 SC, inside and out, it's time to put it to the test. Well, Benchmark is our first name, so don't worry. There are a wide variety of tests waiting for you in the next several sections. Let's start off with a complete description of the Video Card Testing Methodology.