EVGA GT 640 4GB GDDR3The EVGA GT 640 4GB Edition (04G-P4-2647-KR) is a mid range video card.  The EVGA GT 640 4GB Edition is a good entry level gaming class video card that supports up to DirectX 11. EVGA historically offered a lifetime warranty but the 196.75 driver defect caused them to change to 3 years with options for more. EVGA does not void the warranty for users who regreased their cards due to thermal throttling. Our old EVGA GTX 260 lasted 5 years and it was still functional when retired.

The EVGA GT 640 4GB Edition  was released June 4, 2012 making it part of the third series of shader model 5 DirectX 11 cards from NVIDIA. This makes the GT 640 a good performer for DirectX 11 class games.

EVGA positions this model to compete with the rival AMD HD 7650 in the highly competitive $90-$110 market.

Today there is a wide range of games that support the DirectX 11 features. Games still generally support DirectX 9 for XP users. Today many games support a span of DirectX versions in order to have the widest compatibility. With XP retired, DirectX 11 will be the platform for the next 5 years anyway.

The Kepler GK107 GPU is  features 1,300 million transistors. By comparison the 8800 series had 700 million transistors. The die for the EVGA GT 640 4GB Edition  SC  is 11×11 mm making a yield of about 500 devices on a 300 mm wafer using 28 nm. This compares to the 24×24 mm size of the GTX 260 on the 65 nm line.

Kepler is a further refinement over the previous Fermi line. The SMX modules have more compute and less control logic and as such are more efficient at demanding compute tasks.

evga-gt-640Kepler uses 192 CUDA cores in each SMX module while the older Fermi uses only 32 CUDA cores. The GT 640  has two SMX units to give it 384  total  CUDA cores.

Compared to the previous GT 430 the new GT 640 dramatically better. It also uses less power. Compared to the old 8600 GT the modern mainstream cards are now dramatically more powerful for a lot less cash.

Kepler also redesigned the control logic to make it more parallel friendly. The modular design will continue with the next generation as the DirectX 11 API matures. Many DX11 features that are being marketed by NVIDIA have actually been around since the XP period. Vista redesigned the graphics system which pushed video card designs and DirectX 11 is simply the refinement of the DX10 work.

The new GTX GPUs embed additional new technology but for the end-user nothing really changed other than raw performance and power management. The GT 640  has 384 active cores. Made on a 28 nm line, the EVGA GT 640  power draw copes with the PCI Express slot easily. The CUDA cores with Kepler are not as powerful as Fermi, however, the SMX design is more capable which is why it’s faster. When comparing CUDA cores with Fermi and Kepler, the Kepler are roughly half as powerful. Kepler is redesigned to provide generally more parallel processing for games.


One of the advantages of the SMX design is that each can be used independently. This is helpful for threaded game engines that need more compute performance that the CPU can deliver. With SLI enabled, this simply increases the pool of SMX modules for available shaders.

This is why games like Rage perked up considerably when tested with the GT 640. Clearly the Kepler architecture is very favorable for games looking forward. Rage features a new engine which is one of games we considered when testing this card.

GK107Unlike consoles, the EVGA GT 640 4GB Edition  can deliver quality games at the full 1920×1080 easily.

  • Idle/2D power mode: approx. 5W
  • Blu-ray & DVD playback mode: approx. 25W
  • Full 3D performance mode: varies – worst case TDP 60W
  • DX12 (feature level 11.0)
  • OpenGL 4.4
  • 6½” length, 4⅜” full height, single slot

The reference NVIDIA GT 640  is roughly 902 MHz. NVIDIA does not run this car faster, so that it can stay within the PCI slot power limits.


The EVGA GT 640 4GB Edition  comes with a pair of DVI connectors and one µHDMI. Adapters for VGA and HDMI are widely available and EVGA includes a VGA adapter with the GT 640. This is typical for the range of gaming cards which support VGA and up.

HDMI is the option we tested the card with, which quickly demonstrated how bad the sound is with PC LCD panels. HDMI is a separate sound system so it can be disabled in favor of better sounding solutions. We use some low cost Altec Lansing speakers that are drastically better sounding than the PA238QR panel. Video cards with HDMI invariably have integrated audio which works fine with a suitable home theatre system. The Altec Lansing speakers have ports for audio in and out making them equally flexible.


GTX 260 GTX 470 GTX 570 EVGA GT 640
Shaders 192 448 480 384
Core Clock (MHz) 576 607 732 902
Shader Clock (MHz) 1242 1215 1644 N/A
Memory Clock (MHz) 999 1647 1900 667
VRAM Size 896 MB 1280 MB 1280 MB 4096 MB
VRAM Width 448-bit 320-bit 320-bit 128-bit
Feature Size 65 nm 40 nm 40 nm 28 nm

At idle you can expect a temperature of 28-35° C but once pushed to 100%, the temperatures will rise to ~70-80° C. Even in the hottest summer weather, the larger fan cooler keeps this EVGA card much cooler with less noise.


CHASSIS RaidMax Mid Tower Chassis
MB Asus P8H61 LE/CSM
CPU Intel i3-2100
RAM 4096MB Kingston DDR3-1333
GPU EVGA GT 640 4GB Edition
PSU Corsair CS450M
MON Acer AL1916
KB/M Microsoft Wireless Desktop 2000 & Wacom Bamboo Capture
OS Linux


All of the benchmarks are available here.


We use video conversion tools as part of the creation of game video files. Using a CUDA enabled converter with H.264 can be as much as 5x faster. Using 2 threads is enough to raise the GPU usage to 65% as the encoder executes discrete cosine transforms in vast numbers. Most modern video tools now have options for both AMD and NVIDIA users.


A a games developer conference in early 2014, Microsoft announced DirectX 12 which will ship with the next Windows release. DX12 is a refinement intended to take better advantage of the multithreaded capability of DX11 cards. With 2 SMX modules, the GT 640 potentially can run 2 separate threads which came boost performance immensely. AMD and NVIDIA both use roughly the same designs which motivated DX12 to be threaded.

In general any gaming grade DX11 card will run DX12 fine. NVIDIA Kepler and Maxwell both very suitable. DX12 will be rapidly supported by games in 2015 following the next Windows release.


Following the release of Windows 10, we upgraded the EVGA GT 640 to support UEFI. The goal was to be able to support secure boot and also to load Windows more quickly. EVGA has UEFI firmware for their cards and their support was quick to provide the correct version with the card product number. In UEFI mode, the BIOS is loaded in higher resolution graphics mode.

The UEFI GOP which is the replacement for the legacy VBIOS standard that goes back to the 1980s. The GOP provides basic graphics modes that can be used by the UEFI components. Legacy systems still work, the VESA standard is fully backwards compatible. We installed the new firmware in legacy mode and the machine experienced no problems. The UEFI is designed more for dealing the disk limits but graphics can be improved as well.

With the UEFI, its now possible to install Windows 10 using the secure boot which will prevent a lot of problems with malware. The does require the use of DVD media as secure boot does not support USB media for security reasons. Windows 10 x64 will use GPT for the boot partition so the disk needs to be wiped. See Hard Disk Cleanup.


The EVGA GT 640 is not the cheapest, but if you want to play games in 2012 then this card is one not bad velue.