NVIDIA GeForce GT 645M
NVIDIA graphics card specifications and benchmark scores
At a Glance
NVIDIANVIDIA GeForce GT 645M Specifications
GPU Core
Shader units and compute resources
The NVIDIA GeForce GT 645M GPU core specifications define its raw processing power for graphics and compute workloads. Shading units (also called CUDA cores, stream processors, or execution units depending on manufacturer) handle the parallel calculations required for rendering. TMUs (Texture Mapping Units) process texture data, while ROPs (Render Output Units) handle final pixel output. Higher shader counts generally translate to better GPU benchmark performance, especially in demanding games and 3D applications.
GT 645M Clock Speeds
GPU and memory frequencies
Clock speeds directly impact the GeForce GT 645M's performance in GPU benchmarks and real-world gaming. The base clock represents the minimum guaranteed frequency, while the boost clock indicates peak performance under optimal thermal conditions. Memory clock speed affects texture loading and frame buffer operations. The GeForce GT 645M by NVIDIA dynamically adjusts frequencies based on workload, temperature, and power limits to maximize performance while maintaining stability.
NVIDIA's GeForce GT 645M Memory
VRAM capacity and bandwidth
VRAM (Video RAM) is dedicated memory for storing textures, frame buffers, and shader data. The GeForce GT 645M's memory capacity determines how well it handles high-resolution textures and multiple displays. Memory bandwidth, measured in GB/s, affects how quickly data moves between the GPU and VRAM. Higher bandwidth improves performance in memory-intensive scenarios like 4K gaming. The memory bus width and type (GDDR6, GDDR6X, HBM) significantly influence overall GPU benchmark scores.
GeForce GT 645M by NVIDIA Cache
On-chip cache hierarchy
On-chip cache provides ultra-fast data access for the GT 645M, reducing the need to fetch data from slower VRAM. L1 and L2 caches store frequently accessed data close to the compute units. AMD's Infinity Cache (L3) dramatically increases effective bandwidth, improving GPU benchmark performance without requiring wider memory buses. Larger cache sizes help maintain high frame rates in memory-bound scenarios and reduce power consumption by minimizing VRAM accesses.
GT 645M Theoretical Performance
Compute and fill rates
Theoretical performance metrics provide a baseline for comparing the NVIDIA GeForce GT 645M against other graphics cards. FP32 (single-precision) performance, measured in TFLOPS, indicates compute capability for gaming and general GPU workloads. FP64 (double-precision) matters for scientific computing. Pixel and texture fill rates determine how quickly the GPU can render complex scenes. While real-world GPU benchmark results depend on many factors, these specifications help predict relative performance levels.
Kepler Architecture & Process
Manufacturing and design details
The NVIDIA GeForce GT 645M is built on NVIDIA's Kepler architecture, which defines how the GPU processes graphics and compute workloads. The manufacturing process node affects power efficiency, thermal characteristics, and maximum clock speeds. Smaller process nodes pack more transistors into the same die area, enabling higher performance per watt. Understanding the architecture helps predict how the GT 645M will perform in GPU benchmarks compared to previous generations.
Power & Thermal
TDP and power requirements
Power specifications for the NVIDIA GeForce GT 645M determine PSU requirements and thermal management needs. TDP (Thermal Design Power) indicates the heat output under typical loads, guiding cooler selection. Power connector requirements ensure adequate power delivery for stable operation during demanding GPU benchmarks. The suggested PSU wattage accounts for the entire system, not just the graphics card. Efficient power delivery enables the GeForce GT 645M to maintain boost clocks without throttling.
GeForce GT 645M by NVIDIA Physical & Connectivity
Dimensions and outputs
Physical dimensions of the NVIDIA GeForce GT 645M are critical for case compatibility. Card length, height, and slot width determine whether it fits in your chassis. The PCIe interface version affects bandwidth for communication with the CPU. Display outputs define monitor connectivity options, with modern cards supporting multiple high-resolution displays simultaneously. Verify these specifications against your case and motherboard before purchasing to ensure a proper fit.
NVIDIA API Support
Graphics and compute APIs
API support determines which games and applications can fully utilize the NVIDIA GeForce GT 645M. DirectX 12 Ultimate enables advanced features like ray tracing and variable rate shading. Vulkan provides cross-platform graphics capabilities with low-level hardware access. OpenGL remains important for professional applications and older games. CUDA (NVIDIA) and OpenCL enable GPU compute for video editing, 3D rendering, and scientific applications. Higher API versions unlock newer graphical features in GPU benchmarks and games.
GeForce GT 645M Product Information
Release and pricing details
The NVIDIA GeForce GT 645M is manufactured by NVIDIA as part of their graphics card lineup. Release date and launch pricing provide context for comparing GPU benchmark results with competing products from the same era. Understanding the product lifecycle helps evaluate whether the GeForce GT 645M by NVIDIA represents good value at current market prices. Predecessor and successor information aids in tracking generational improvements and planning future upgrades.
About NVIDIA GeForce GT 645M
The NVIDIA GeForce GT 645M is a 28 nm Kepler-based GPU from the GeForce 600M generation, fabricated by TSMC with 1,270 million transistors on a 118 mm² die. Its Geekbench OpenCL score of 2665 places it in the 15th percentile of all GPUs, making it an entry-level part. With a 32 W TDP and no power connectors, it targets low-power mobile systems. The GPU features 384 shading units, 32 TMUs, and 16 ROPs, but its DDR3 memory and 128-bit bus limit bandwidth to 28.80 GB/s. The data shows a part that is essentially tied with a cluster of low-end rivals, and it is now end-of-life.
How It Compares
The GT 645M trails the NVIDIA Quadro K1100M by a razor-thin 0.5% in average benchmark score (2665 vs. 2678). This places the two effectively in the same performance tier, despite the Quadro’s professional positioning. For general compute workloads, the difference is negligible—less than one percent—so users upgrading from or considering either part should expect no meaningful performance gap.
Against the NVIDIA GeForce GT 440, the GT 645M holds a 1.4% lead (2665 vs. 2629). This is a small but consistent advantage. The GT 440 is an older desktop part, yet the margin is within the noise of typical benchmark variation. In practical terms, the GT 645M is not faster in any perceptible way; it simply edges out the competition on paper.
The GT 645M is 1.7% ahead of the NVIDIA GeForce GT 720M (2665 vs. 2621). The GT 720M is a later mobile GPU, and the delta is again minimal. Both share similar memory configurations and compute capabilities. The GT 645M’s slightly higher score suggests a marginal edge in OpenCL compute, but not enough to influence real-world application performance.
The most telling comparison is against the Intel UHD 610, an integrated graphics solution. The GT 645M is 3.2% slower (2665 vs. 2755). This is the largest delta among its nearest rivals, and it means the dedicated GT 645M is actually outperformed by a modern integrated GPU. For users relying on the CPU’s graphics, the GT 645M offers no advantage in raw compute; it only brings a separate memory pool and a 32 W TDP.
Ray Tracing and Feature Set
The GT 645M has no ray tracing cores and no tensor cores, as indicated by null values in the fact pack. This means it lacks dedicated hardware for real-time ray tracing, DLSS, or any AI-accelerated features. The GPU is based on the Kepler architecture, which predates these technologies. Its feature set is defined by the APIs it supports: DirectX 12 (feature level 11_0), OpenGL 4.6, and Vulkan 1.2.175. The DirectX 12 support is limited to the 11_0 feature level, so it cannot take advantage of the full DirectX 12 feature set, such as mesh shaders or variable rate shading. Vulkan 1.2.175 provides modern low-level access, but the hardware’s compute throughput is constrained by its 599.0 GFLOPS FP32 performance.
The GPU’s shading resources are modest: 384 shading units, 32 texture mapping units, and 16 raster output units. The pixel rate is 6.240 GPixel/s, and the texture rate is 24.96 GTexel/s. These numbers indicate a part that can handle basic 2D rendering and light 3D tasks, but it will struggle with high-resolution textures or complex geometry. The lack of tensor cores also eliminates any possibility of AI-based upscaling or frame generation, further limiting its relevance in modern gaming.
Benchmark Performance
The only benchmark available is Geekbench OpenCL, where the GT 645M scores 2665. This places it in the 15th percentile of all GPUs, meaning 85% of the GPUs in the database perform better. The score is nearly identical to its nearest rivals: 0.5% below the Quadro K1100M, 1.4% above the GT 440, 1.7% above the GT 720M, and 3.2% below the Intel UHD 610. These deltas are all within a few percentage points, indicating that the GT 645M occupies a very narrow performance band.
The small margins suggest that the GT 645M is not a meaningful upgrade over its competitors. In fact, its performance is so close to that of an integrated GPU (Intel UHD 610) that the discrete nature of the GT 645M provides no tangible compute advantage. The 599.0 GFLOPS FP32 throughput is consistent with a low-end Kepler chip, but the memory bandwidth of 28.80 GB/s is a bottleneck for any workload that requires frequent data transfers. The pixel and texture rates are similarly limited, so the GPU is best suited for tasks that are compute-light and do not demand high fill rates.
Who Should Consider It
Given the benchmark results, the GT 645M is only suitable for basic computing tasks: office applications, video playback, and legacy software that does not rely on advanced graphics features. The 15th percentile ranking means it is outperformed by the vast majority of GPUs, including many integrated solutions. Users who need a discrete GPU for a low-power system—where the 32 W TDP and lack of power connectors are advantages—might consider it, but they should not expect to run modern games or GPU-accelerated workloads beyond the simplest level.
The memory subsystem, with 2 GB of DDR3 on a 128-bit bus, provides only 28.80 GB/s of bandwidth. This is insufficient for high-resolution textures or multi-monitor setups. The GPU’s pixel rate of 6.240 GPixel/s and texture rate of 24.96 GTexel/s further limit its ability to handle demanding scenes. For users who prioritize power efficiency over performance, the GT 645M could serve as a basic display adapter, but its end-of-life status and lack of modern features make it a poor choice for anyone seeking a future-proof solution.
FAQ
Q: Does the GT 645M support real-time ray tracing?
A: No. The GPU has no ray tracing cores (rtCores: null) and no tensor cores (tensorCores: null), so it lacks dedicated hardware for ray tracing or AI acceleration.
Q: What DirectX version does it support?
A: It supports DirectX 12 with feature level 11_0, along with OpenGL 4.6 and Vulkan 1.2.175. The DirectX 12 support is limited to the 11_0 feature level, not the full DirectX 12 feature set.
Q: How much memory does it have and what is the bus width?
A: It has 2 GB of DDR3 memory on a 128-bit bus, providing a bandwidth of 28.80 GB/s. The memory clock is 900 MHz, with an effective data rate of 1800 Mbps.
Q: What is the power consumption and connector requirement?
A: The TDP is 32 W, and it requires no power connectors (powerConnectors: None). The slot width is listed as IGP, indicating an integrated form factor.
Q: What is the GPU’s performance percentile?
A: It is in the 15th percentile of all GPUs, meaning it performs better than only 15% of the GPUs in the database.
Q: When was it released?
A: It was released on September 30, 2012. It is now end-of-life, with the GeForce 500M as its predecessor and the GeForce 700M as its successor.
Memory Subsystem
The GT 645M is equipped with 2 GB of DDR3 memory on a 128-bit bus. The memory clock is 900 MHz, with an effective data rate of 1800 Mbps, yielding a bandwidth of 28.80 GB/s. This bandwidth is a critical limitation: at high resolutions, the GPU will be unable to feed its shading units quickly enough, leading to frame rate drops in any memory-intensive scenario. The 128-bit bus is narrow by modern standards, and the DDR3 type is slower than GDDR5 or GDDR6. The pixel rate of 6.240 GPixel/s and texture rate of 24.96 GTexel/s further constrain performance, as the GPU can only fill a limited number of pixels and texels per second.
For users aiming to drive a 1080p display with high-quality textures, the memory subsystem will be a severe bottleneck. The 2 GB capacity is sufficient for basic tasks, but the low bandwidth means that even moderate resolutions will expose the GPU’s weaknesses. The data shows that the GT 645M is not designed for high-resolution gaming or content creation; it is a low-power part meant for light usage.
Power and Cooling
The GT 645M has a TDP of 32 W, which is exceptionally low for a discrete GPU. It requires no power connectors, as indicated by the "None" entry, and its slot width is listed as IGP. This suggests that the GPU is intended to be soldered or integrated into a compact motherboard, drawing all power from the PCIe slot. The lack of a suggested PSU in the fact pack reinforces that this is a low-power component that does not demand a separate power supply.
The 32 W TDP means that cooling can be modest—a small heatsink or fan is sufficient. The GPU’s production status is end-of-life, so it is no longer manufactured. For users with legacy systems that require a low-power GPU, the GT 645M could be a drop-in replacement, but its performance limitations and lack of modern features make it a poor investment for any new build. The absence of power connectors simplifies installation, but the trade-off is a GPU that cannot be pushed beyond its modest capabilities.
Detailed benchmark scores and charts for the NVIDIA GeForce GT 645M are below.
Benchmark Scores
geekbench_metalSource
Geekbench Metal tests GPU compute using Apple's Metal API. This shows how NVIDIA GeForce GT 645M performs in macOS and iOS applications that leverage GPU acceleration.
Top 5 Performers
Top 5 PerformersNearby Performers
Nearby Performersgeekbench_openclSource
Geekbench OpenCL tests GPU compute performance using the cross-platform OpenCL API. This shows how NVIDIA GeForce GT 645M handles parallel computing tasks like video encoding and scientific simulations. OpenCL is widely supported across different GPU vendors and platforms. Higher scores benefit applications that leverage GPU acceleration for non-graphics workloads.
Top 5 Performers
Nearby Performers
geekbench_vulkanSource
Geekbench Vulkan tests GPU compute using the modern low-overhead Vulkan API. This shows how NVIDIA GeForce GT 645M performs with next-generation graphics and compute workloads.
Top 5 Performers
Nearby Performers
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