ECS GeForce GT 640 Reviewformerstaff - May 13, 2013
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ECS GeForce GT 640 Closer Look:
The GT 640 is based on a scaled down Kepler architecture: the GK107. The GT 640 itself is very small, dual width card measuring in at 5.70 inches in length (barely the length of the PCIe slot it occupies) and 4.38 inches in height. To say the card itself is inconspicuous would be up for understatement of the year. A small 60mm fan with a beveled shroud sits atop the 28nm Kepler core using an all aluminum radial split fin heat sink. The design of the heat sink and lack of an additional power connector is an indication of how the GT 640 sips less power than even the 75W afforded by the PCIe interface. The rest of the PCB is sparsely littered with a few capacitors, two power phases, and is PCIe 3.0 compatible for the generation of motherboards so equipped.
Display connectivity consists of one Dual Link DVI-I, one Dual Link DVI-D, and a Mini HDMI. The ECS GT 640 supports NVIDIA multi monitor surround output with maximum digital resolution of 4096x2160 and 2048x1536 maximum VGA resolution. The GT 640 also supports HDMI, HDCP, and an internal audio input for HDMI. Like the rest of the Kepler line up, the GK107 is setup for DX11, Open GL 4.3, and Open CL 1.2. While this is a low end card, the subject of SLI'ing the GT 640 would rarely come up, but note there are no SLI bridge connectors.
The GT 640 is also 3D Vision Ready with support for 3D Blu-ray and 3D Photos in addition to the 3D surround I mentioned earlier. For those using triple monitors all of the DVI persuasion, fear not. You can add an HDMI to DVI adapter to the provided DisplayPort to HDMI adapter and you are good to go as pictured in the bottom image. (Note the HDMI to DVI adapter is not included with the GT 640 accessories.)
The cooling solution capping the GK107 Kepler of the ECS GT 640 is rather petite as you might expect for a 65W graphics card that requires that you have only a 350W power supply aboard. The 60mm fan is of Cooler Master make, model number FA06010H12LNA, and electrically is a 12v 0.45A part and is topped off with a small ECS Elite Group sticker on the hub. The Cooler Master fan sits atop an all aluminum radial split fin heat sink that is attached to the PCB by four spring loaded screws from the back of the card. The aluminum heat sink does an adequate job of dissipating the limited heat generated by the GK107 chip as well as providing cooling to the VRM components by way of airflow from the down force directed and focused by the beveled shroud the fan is nested in. The fan solution runs relatively loud as you would expect from small, high RPM fans and is noticed over other fans in the system.
Removing the cooling solution via the four spring loaded screws gives us a look at the Kepler GK107 graphics processor with its generous allotment of thermal compound. The GK107 is of the 28nm fabrication process and made in Taiwan by TSMC. The GK107 has a die size of 118mm² with 1.3 billion transistors and 384 CUDA cores. Our ECS GT 640 core is clocked at 930MHz while the shader cores are clocked at 1860MHz. This coupled with a 128-bit bus and the choice of the slower DDR3, the GK107 has a GFLOP rating of 691 GFLOPS of computing power. I was unable to make out the model of voltage controller used here on the ECS GT 640, so unfortunately I cannot report on this.
Unlike its high end and midrange siblings, the GT 640's GK107 carries no boost technology to take it to the maximum core frequency during high loads, however it does retain the Adaptive V-Sync feature to reduce screen tearing. While taking a look at the specs it appears that some of them are impressive for a low end part with its architectural configuration of 384 cores, 32 texture units, and 16 ROPs. However, you may run into a weakest link scenario and the higher clocks and generous allotment of frame buffer may be limited by bus width and the use of the slower DDR3. The upcoming benchmarks, however will ferret this out.
Surrounding the GK107 processor on two sides are eight 256MB Samsung memory chips that carry the model number K4W2G1646C HC11 and are clocked at 1782MHz (effective rate). The inclusion of 2048MB of DDR3 on the GK107 will most likely prove to be superfluous, but we shall forge on to find out. Installed in the system the GT 640 takes an unassuming appearance with its single slot stature, no external power connector, and the end of the card being even with the PCIe slot.
The GT 640 touts itself as an upgrade from todays' integrated graphics solutions so let's heat it up against one of the top IGPs and see how it fares in both features and raw power. Next have a look at the features and specifications and then we will do just that.