GeForce GT 645M vs GeForce 840M
Summary
Reasons to consider GeForce GT 645M |
| Supports PhysX |
| Supports G-Sync |
| Supports ShadowPlay (allows game streaming/recording with minimum performance penalty) |
| Based on an outdated architecture (Nvidia Kepler), there are less performance optimizations for current games and applications |
Reasons to consider GeForce 840M |
| This is a much newer product, it might have better long term support. |
| Higher theoretical gaming performance, based on specifications. |
| Supports PhysX |
| Supports G-Sync |
| Supports ShadowPlay (allows game streaming/recording with minimum performance penalty) |
| Based on an outdated architecture (Nvidia Maxwell), there may be no performance optimizations for current games and applications |
HWBench recommends GeForce 840M
Based on theoretical specifications.
Core Configuration
| GeForce GT 645M | | GeForce 840M | |
|---|
| GPU Name | GK107 (N13P-GS) | vs | GM108 (N15S-GT) |
| Fab Process | 28 nm | vs | 28 nm |
| Die Size | 118 mm² | vs | 0 mm² |
| Transistors | 1,270 million | vs | unknown |
| Shaders | 384 | vs | 384 |
| Compute Units | 2 | vs | 3 |
| Core clock | 709 MHz | vs | 1029 MHz |
| ROPs | 16 | vs | 8 |
| TMUs | 32 | vs | 16 |
Memory Configuration
| GeForce GT 645M | | GeForce 840M | |
|---|
| Memory Type | DDR3 | vs | DDR3 |
| Bus Width | 128 bit | vs | 64 bit |
| Memory Speed | 900 MHz
1800 MHz effective | vs | 1001 MHz
2002 MHz effective |
| Memory Size | 2048 Mb | vs | 1024 Mb |
Additional details
| GeForce GT 645M | | GeForce 840M | |
|---|
| TDP | 32 watts | vs | 33 watts |
| Release Date | 1 Oct 2012 | vs | 12 Mar 2014 |
GeForce GT 645M
5.67 GP/s
GeForce 840M
8.23 GP/s
GigaPixels - higher is better
GeForce GT 645M
22.69 GT/s
GeForce 840M
16.46 GT/s
GigaTexels - higher is better
GeForce GT 645M
28.80 GB/s
GeForce 840M
16.02 GB/s
GB/s - higher is better
GeForce GT 645M
544.50 GFLOPs
GeForce 840M
790.30 GFLOPs
GFLOPs - higher is better