ECS GeForce GT 640 Review

formerstaff - 2012-11-20 13:28:53 in Video Cards
Category: Video Cards
Reviewed by: formerstaff   
Reviewed on: May 13, 2013
Price: $85

ECS GeForce GT 640 Introduction:

The other week OCC took a highly anticipated and extensive look at NVIDIA's (and the world's) fastest single GPU solution to date with the 4.5 teraflop, seven billion transistor Titan. On the other end of the scale NVIDIA slipped the lower end of the Kepler solutions into the mix to round out the lineup of discrete cards without fanfare or introduction. The GT 640 is a 28nm GK107 Kepler-based GPU with a mere 384 CUDA units and no power connectors. ECS chose a rather odd combination for the GT 640 when equipping the card with memory. The low end card carries a full 2GB of frame buffer, however it is made up of the slower DDR3 rather than DDR5 that's now standard fare on today's discrete graphics cards. The GT 640 is also missing some of the basic features of the rest of the Kepler lineup leaving us wondering where it fits in.

So where does this combination of components put the cut down Kepler in a matter of practical use? An HTPC build or casual gaming? Being a single slot graphics solution that peaks its consumption at 65W it will certainly have the low draw and petite space profile to be put into just about any build or added to an OEM machine with the chosen PCIe slot providing all the power that this little Kepler will ever need. We are going to put the ECS GeForce GT 640 through its paces along side a strong integrated graphics solution to ferret out what's what.

ECS GeForce GT 640 Closer Look:

The ECS GeForce GT 640 arrives in a small but very eye catching box featuring the likeness of a leather and amour clad Xena-looking female warrior from the Medieval period going for her Claymore. It looks as if she could kick your butt up one side and down the other while flames roar behind her. Besides the eye catching mural, not a whole lot of other information is found on the front cover of the box other than the name of the product and that we have 2048MB of DDR3 at our disposal.








The back of the box affords a bit more information about where the GT 640 is intended to be slotted in the market. It makes it clear that the GT 640 Is the entry level jumping off point for gaming. NVIDIA is touting up to seven times the power of todays' integrated graphics solution in its bid to have you replace your current IGP with the GK107 discrete solution. The GT 640 is also capable of running three monitors with NVIDIA Surround technology and the ability to be connected to an HD television for Blu-ray playback.


There is no box inside the box for the GT 640. Wrapped up in an anti-static bag is our subject of interest, fit snugly inside the pre-formed cardboard.


Underneath the card itself are the items of a very basic bundle you would expect of a card in this category. You receive a user manual, install guide, and a VGA driver disc you will want to ignore and install the latest driver set from NVIDIA's website. Lastly the GT 640 comes with a pair of video connection adapters including a VGA to Dual Link DVI, and an HDMI to DisplayPort adapter. Very basic, but what you need to get you up and running.


Well that's how the ECS GeForce GT 640 is dressed. Let's have a look at the card itself and under the hood.

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.

ECS GeForce GT 640 Specifications:


GPU Engine Specs:
CUDA Cores
Graphics Clock (MHz)
Texture Fill Rate (billion/sec)
Memory Specs:
Memory Clock
1.8 Gbps
Standard Memory Config
2048 MB
Memory Interface
Memory Interface Width
Memory Bandwidth (GB/sec)
Feature Support:
Bus Support
PCI Express 3.0
Certified for Windows 7
Supported Technologies
3D Vision, Surround, DirectX 11, CUDA, PhysX
3D Vision Ready
Display Support:
Multi Monitor
Maximum Digital Resolution1
Maximum VGA Resolution
Standard Display Connectors
Dual Link DVI-I, Dual Link DVI-D, Mini HDMI
Audio Input for HDMI
Standard Graphics Card Dimensions:
5.70 inches
4.38 inches
Thermal and Power Specs:
Maximum GPU Tempurature (in C)
Maximum Graphics Card Power (W)
Minimum System Power Requirement (W)
3D Vision Ready:
3D Blu-Ray
3D Photos



ECS GeForce GT 640 Features:




All information courtesy of ECS Elite Group @

ECS GeForce GT 640 Testing:

Testing of the NVIDIA ECS GeForce GT 640  will consist of running it and comparison cards through the suite of games and synthetic benchmarks. This will test the performance against many popular competitors. Comparisons will be made to cards of a range of capabilities to show where each card falls on the performance ladder. The games used are some of today's newest and most popular titles, which should be able to provide an idea of how the cards perform relative to each other.

The system specifications will remain the same throughout the testing. No adjustment will be made to the respective control panels during the testing, with the exception of the 3DMark 11 testing, where PhysX will be disabled in the NVIDIA Control Panel, if applicable. I will first test the cards at stock speeds, and then overclocked to see the effects of an increase in clock speed. The cards will be placed in order from highest to lowest performance in each graph to show where they fall by comparison. The AMD comparison cards will be using the 13.3 drivers with Nvidia GT 640 cards using the 314.07 drivers.


Testing Setup:


Comparison Video Cards:




To overclock the ECS GT 640 we will be using the EVGA Precision overclocking tool. The GT 640 proved to be a decent overclocker, being able to be pushed from an already non-reference frequency of 930MHz to 1101MHz. We will see, however, in the upcoming tests that the effect of this overclock is somewhat hampered by the cut down shader count, the use of slower DDR3, and a 128-bit bus. This proved to be all the frequency that the GT 640 had in it with additional voltage having no effect in the pursuit of a higher overclock. 


Maximum Clock Speeds:

Testing for the maximum clock speed consisted of looping Unigine 3.0 for 30 minutes each to see where the clock speeds failed when pushed. If the clock speed adjustment failed, then the clock speeds and tests were rerun until they passed a full hour of testing.



  1. Metro 2033
  2. Batman: Arkham City
  3. Battlefield 3
  4. Unigine Heaven Benchmark 4.0
  5. Sid Meier's Civilization V
  6. DiRT 3
  7. Mafia II
  8. 3DMark 11


  1. Temperatures
  2. Power Consumption

ECS GeForce GT 640 Testing:

Part first-person shooter, part survival horror, Metro 2033 is based on the novel of the same name, written by Russian author Dmitry Glukhovsky. You play as Artyom in a post-apocalyptic Moscow, where you'll spend most of your time traversing the metro system, with occasional trips to the surface. Despite the dark atmosphere and bleak future for mankind, the visuals are anything but bleak. Powered by the 4A Engine, with support for DirectX 11, NVIDIA PhysX, and NVIDIA 3D Vision, the tunnels are extremely varied – in your travels, you'll come across human outposts, bandit settlements, and even half-eaten corpses. Ensuring you feel all the tension, there is no map and no health meter. Get lost without enough gas mask filters and adrenaline shots and you may soon wind up as one of those half-eaten corpses, chewed up by some horrifying manner of irradiated beast that hides in the shadows just waiting for some hapless soul to wander by.













The onboard graphics of the AMD solution jumps out to an early lead by about 14% over the discrete NVIDIA solution in probably the most graphically pure test. The overclock seems to yield less, possibly because of the slower DDR3 and 128-bit bus.

ECS GeForce GT 640 Testing:

Batman: Arkham City is the sequel to Batman: Arkham Asylum released in 2009. This action adventure game based on DC Comics' Batman super hero was developed by Rocksteady Studios and published by Warner Bros. Interactive Entertainment. Batman: Arkham City uses the Unreal 3 engine.















The GT 640 gets the better of BAC, but the AMD APU catches the GK107 when overclocked.

ECS GeForce GT 640 Testing:

Battlefield 3 is a first-person shooter video game developed by EA Digital Illusions CE and published by Electronic Arts. Battlefield 3 uses the Frostbyte 2 game engine and is the direct successor to Battlefield 2. Released in North America on October 25, 2011, the game supports DirectX 10 and 11.


















At stock clocks the GT 640 outruns the AMD by 22% and 10% when overclocked.

ECS GeForce GT 640 Testing:

Unigine Heaven Benchmark 4.0 is a DirectX 11 GPU benchmark based on the Unigine engine. This was the first DX 11 benchmark to allow testing of DX 11 features. What sets the Heaven Benchmark apart is the addition of hardware tessellation, available in three modes – Moderate, Normal and Extreme. Although tessellation requires a video card with DirectX 11 support and Windows Vista/7, the Heaven Benchmark also supports DirectX 9, DirectX 10, DirectX 11 and OpenGL 4.0. Visually, it features beautiful floating islands that contain a tiny village and extremely detailed architecture.















The Kepler architecture is a tessellation monster and despite the GK107 being a stripped down version, it bests its AMD counterpart in Heaven 3.0. It's an epitome of tessellation for the future of 3D gaming.

ECS GeForce GT 640 Testing:

Civilization V is a turn-based strategy game. The premise is to play as one of 18 civilizations and lead the civilization from the "dawn of man" up to the space age. This latest iteration of the Civilization series uses a new game engine and massive changes to the way the AI is used throughout the game. Civilization V is developed by Firaxis Games and is published by 2K games and was released for Windows in September of 2010. Testing will be done using actual game play with FPS measured by Fraps through a series of five turns, 150 turns into the game.
















The Kepler and GCN run a dead heat at stock speed but the GK107 just edges by when overclocked. So far the benches seem to show that the GK107 is a bit handcuffed by the slow DDR3 and 128-bit bus that NVIDIA paired with this lower end GPU.

ECS GeForce GT 640 Testing:

DiRT 3 is the third iteration of this series. Published and developed by Codemasters, this game uses the EGO 2.0 game engine and was released in the US on PC in May of 2011.
















The GT 640 gets seven frames up on the AMD in DiRT 3 and holds the lead when overclocked.

ECS GeForce GT 640 Testing:

Mafia II is a third-person shooter that puts you into the shoes of a poor, Sicilian immigrant, Vito Scarletta. Vito has just returned home from serving overseas in the liberation of fascist Italy, to avoiding his jail sentence, to finding his family in debt. The debt must be repaid by the end of the week, and his childhood friend, Joe Barbaro, conveniently happens to have questionable connections that he assures will help Vito clear the debt by that time. As such, Vito is sucked into a world of quick cash. Released in North America for PC in August of 2010, the game was developed by 2K Czech, published by 2K, and uses the Illusion 1.3 game engine.















In this title the GT 640's Kepler architecture is just a better pairing both at stock and overclocked settings.

ECS GeForce GT 640 Testing:

3DMark 11 is the next installment in Futuremark’s 3DMark series, with Vantage as its predecessor. The name implies that this benchmark is for Microsoft DirectX 11 and with an unintended coincidence, the name matches the year proceeding its release (which was the naming scheme to some prior versions of 3DMark nonetheless). 3DMark 11 is designed solely for DirectX 11, so Windows Vista or 7 are required along with a DirectX 11 graphics card in order to run this test. The Basic Edition has unlimited free tests on performance mode, whereas Vantage is only allowed for a single test run. The advanced edition costs $19.95 and unlocks nearly all of the features of the benchmark, while the professional edition runs $995.00 and is mainly suited for corporate use. The new benchmark contains six tests, four of which are aimed only at graphical testing; one to test for physics handling and one to combine graphics and physics testing together. The open source Bullet Physics library is used for physics simulation and although not as mainstream as Havok or PhysX, it still seems to be a popular choice.

With the new benchmark, comes two new demos that can be watched, both based on the tests. Unlike the tests, however, these contain basic audio. The first demo is titled "Deep Sea" and involves a few vessels exploring what looks to be a sunken U-Boat. The second demo is titled "High Temple" and presents a location similar to South American tribal ruins with statues and the occasional vehicle around. The demos are simple in that they have no story – they are really just a demonstration of what the testing will be like. The vehicles have the logos of the sponsors MSI and Antec on their sides – the sponsorships helping to make the basic edition free. The four graphics tests are slight variants of the demos. I will use the three benchmark test preset levels to test the performance of each card. The presets are used as they are comparable to what can be run with the free version, so that results can be compared across more than just a custom set of test parameters.













In the 3DMark 11 benchmark the GK107 shows the low end tessellation grunt it has and outperforms the APU solution.

ECS GeForce GT 640 Testing:

Temperature testing will be accomplished by loading the video card to 100% using Unigine's Heaven Benchmark Version 3.0, with MSI's Afterburner overclocking utility for temperature monitoring. I will be using a resolution of 1920x1200 using 8xAA and a five-run sequence to run the test, ensuring that the maximum thermal threshold is reached. The fan speed will be left in the control of the driver package and video card's BIOS for the stock load test, with the fan moved to 100% to see the best possible cooling scenario for the overclocked load test. The idle test will involve a 20-minute cool-down, with the fan speeds left on automatic in the stock speed testing and bumped up to 100% when running overclocked.














The temperatures for the ECS GeForce GT 640 are acceptable considering that it comes equipped with a very small aluminum finned heat sink. Even overclocked the temperatures stay in the safe 70's and only rise a couple of degrees.

ECS GeForce GT 640 Testing:

Power consumption of the system will be measured at both idle and loaded states, taking into account the peak voltage of the system with each video card installed. I will use Unigine's Heaven Benchmark version 2.5 to put a load onto the GPU using the settings below. A 15-minute load test will be used to heat up the GPU, with the highest measured temperature recorded as the result. The idle results will be measured after 15 minutes of inactivity on the system. With dual-GPU setups, the two core temperatures will be averaged.













As expected of a card with no additional power connections, the power is sipped by the GT 640's GK107 architecture.The total draw is well under the 75W afforded by the PCIe slot.

ECS GeForce GT 640 Conclusion:

NVIDIA released the GK107 GT 640 without much ado a while back to round out the lower end of the 600 Series Kepler lineup. After putting the screws to it now I understand the low key approach to its release. The ECS GeForce GT 640 is a rather difficult card to spec a use for. It does what it does well, however it is a bit of a good news/bad news proposition. On one hand NVIDIA outfitted the GT 640 with a hefty 2GB of memory; on the other hand the GPU cannot come close to making use of it because of the cut down nature of the GK107 GPU. Even if it could the slow speed of the DDR3 and 128-bit bus would prevent it from doing so.

The card can be slipped into just about any system due to its stealthy, single slot configuration, making it an attractive option for those building a home theater PC. However, as you would expect an 60mm fan needs to spin at high speed and can raise a ruckus when the card is being worked hard and gets up around 65 °C.

It continues this way for the GT 640 in just about every facet of the card. While it sips power requiring, only a portion of the 75W afforded by the PCIe slot, there is no answer to AMD ZeroCore or the GPU Boost found on the GTX 650 Ti and up through the product line. One of the GT 640's strong points is its tessellation ability for a card on this end of the spectrum. Unfortunately the consumer will probably never be able to exploit this strength because of the lower capability of the card. It simply runs out of cores and rendering units to make use of this while gaming.

The ECS GeForce Gt 640 is sitting at between $90-$110 and that simply puts it at a price point that does not make sense. The performance is on par with the AMD HD 6670 and the onboard graphics of the A10-5800K. To add to this, the GT 640's performance as a discrete card can be had for a scant $60 right now by the competition. I did have an occasion to try the GT 640 as a dedicated PhysX card and it performed quite well. For the minority of users who are considering setting up a PC in this way, it seems that 384 CUDA cores is an ample array to carry out the physics duties for most games that have it.

The GT 640 was released as a $110 GPU solution that put it in the stratosphere, competitively speaking. At $90 it is still out of range when you consider the competitions offerings and the price/performance of the rest of the stellar NVIDIA Kepler lineup.