NVIDIA GeForce GT 640 vs NVIDIA GeForce GT 755M Comparison

The NVIDIA GeForce GT 755M and the NVIDIA GeForce GT 640 are both Kepler-based graphics processors from NVIDIA, but they target different segments of the mobile and desktop markets respectively. The data in the database shows a clear performance hierarchy, with the GT 755M leading in every recorded benchmark. This analysis breaks down the measured results, architectural similarities, and specification differences to provide a clear picture of where each card stands.

Head-to-Head Benchmarks

The recorded head-to-head benchmark results show a decisive victory for the NVIDIA GeForce GT 755M. In the Geekbench Metal test, the GT 755M scored 3132, while the GT 640 scored 2086. This represents a 50.1% advantage for the GT 755M, which is a substantial margin in real-world compute workloads. The Metal API is primarily used on Apple platforms, and the score reflects the raw compute capability of the GPU under that interface.

The Geekbench OpenCL test tells a similar story, though with a slightly smaller gap. The GT 755M achieved a score of 4934, while the GT 640 managed 3736. The delta here is 32.1% in favor of the GT 755M. OpenCL is a more widely supported cross-platform compute standard, and the results indicate that the GT 755M has a significant edge in general-purpose GPU compute tasks.

Across the two recorded benchmarks, the GT 755M wins both, giving it a 2-0 record in head-to-head comparisons. The average benchmark score across all tests in the database reinforces this: the GT 755M sits at 4033, while the GT 640 sits at 3210. That is a difference of roughly 25.6% in the overall average, which aligns closely with the OpenCL margin and underscores the consistency of the GT 755M's advantage.

When looking at the broader competitive landscape, the GT 755M's average score of 4033 places it near the AMD FirePro M4150, which averages 4013, a delta of 0.5% in favor of the GT 755M. It also sits just below the Intel HD Graphics 630, which scores 4075, a 1% deficit for the GT 755M. The AMD Radeon HD 6850 X2 is slightly behind with 3977, giving the GT 755M a 1.4% lead. Interestingly, the AMD Radeon RX 9060 XT 8 GB scores 4093, which is 1.5% higher than the GT 755M, showing that even a modern card only edges out this older mobile part by a small margin in these specific compute tests.

The GT 640, on the other hand, with an average of 3210, sits close to the Intel Arc Pro B60, which averages 3182, a 0.9% delta in favor of the GT 640. It also edges out the NVIDIA Quadro P1000, which scores 3163, by 1.5%. However, the NVIDIA GeForce 920M is slightly ahead at 3287, a 2.3% lead for the 920M, and the NVIDIA GeForce GT 730M is also ahead at 3316, a 3.2% margin. This puts the GT 640 in a relatively tight cluster of lower-end GPUs, where small percentage differences separate the contenders.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The NVIDIA GeForce GT 755M has a significantly higher average benchmark score of 4033, compared to the NVIDIA GeForce GT 640's 3210. This represents a substantial overall performance gap in the recorded data.

Q: How much faster is the GT 755M in the Geekbench Metal test?

A: The GT 755M scores 3132 in Geekbench Metal, while the GT 640 scores 2086. The GT 755M is 50.1% faster than the GT 640 in this specific test, according to the recorded head-to-head benchmark data.

Q: What is the memory bandwidth difference between the two cards?

A: The GT 755M has a memory bandwidth of 86.40 GB/s, while the GT 640 has a memory bandwidth of 28.51 GB/s. The GT 755M's bandwidth is roughly three times higher, which is a major factor in its performance advantage.

Q: Do both GPUs support the same DirectX and Vulkan versions?

A: Yes, both the GT 755M and the GT 640 support DirectX 12 (11_0) and Vulkan 1.2.175. They also both support OpenGL 4.6, so the API feature set is identical between the two.

Q: What is the TDP of each card?

A: The GT 755M has a TDP of 50 W, while the GT 640 has a TDP of 65 W. This is notable because the GT 755M delivers higher performance while consuming less power.

Q: Which card has a higher pixel rate?

A: The GT 755M has a pixel rate of 8.160 GPixel/s, while the GT 640 has a pixel rate of 7.216 GPixel/s. The GT 755M is ahead by about 13.1% in this metric.

Architecture Differences

Both the NVIDIA GeForce GT 755M and the NVIDIA GeForce GT 640 are built on the same fundamental architecture. They share the GK107 chip, which is based on NVIDIA's Kepler architecture. The manufacturing process is identical at 28 nm, and both are produced by TSMC. The transistor count is the same at 1,270 million, and the die size is also the same at 118 mm². This results in an identical transistor density of 10.8M per mm².

The core configuration is also identical on paper. Both GPUs have 384 shading units, 32 texture mapping units (TMUs), and 16 raster output units (ROPs). Neither GPU has dedicated ray tracing cores or tensor cores, which is expected for Kepler-generation hardware. The bus interface is PCIe 3.0 x16 for both.

The key architectural difference lies in the memory subsystem. The GT 755M uses GDDR5 memory, while the GT 640 uses DDR3 memory. This is a crucial distinction because GDDR5 is designed for much higher bandwidth. The GT 755M's memory clock is listed at 1350 MHz with 5.4 Gbps effective data rate, while the GT 640's memory clock is 891 MHz with 1782 Mbps effective. The memory bus width is the same at 128 bit for both, but the different memory types and clock speeds lead to a massive bandwidth gap.

The GT 755M also has a higher base clock of 980 MHz and a boost clock of 1020 MHz. The GT 640 does not have a listed base or boost clock in the database, which suggests it may run at a fixed clock or the data was not recorded. The higher clocks on the GT 755M contribute to its superior compute throughput.

The GT 755M is designed as an MXM module, which is a form factor for laptops and mobile workstations. The GT 640 is a single-slot desktop card with a length of 145 mm (5.7 inches). This reflects their different target markets: one is for portable devices, the other for desktop systems.

The production status for both is end-of-life, and they were released about a year apart. The GT 640 was released on 2012-06-04, while the GT 755M was released on 2013-06-24. The GT 755M is a successor to the GeForce 600M series, and its own successor is the GeForce 800M. The GT 640 is part of the GeForce 600 series, with its predecessor being GeForce 500 and its successor being GeForce 700.

Specification Differences

The specification table shows several key differences between the two cards. The most impactful difference is in memory type and bandwidth. The GT 755M uses GDDR5 memory with a bandwidth of 86.40 GB/s, while the GT 640 uses DDR3 memory with a bandwidth of 28.51 GB/s. Both have 2 GB of memory and a 128 bit bus, but the memory technology alone accounts for a threefold difference in bandwidth.

Clock speeds also differ. The GT 755M has a base clock of 980 MHz and a boost clock of 1020 MHz. The GT 640 has no recorded base or boost clock, leaving its core clock unspecified in the database. The memory clock is 1350 MHz (5.4 Gbps effective) for the GT 755M and 891 MHz (1782 Mbps effective) for the GT 640.

The compute rates reflect these clock differences. The GT 755M has a pixel rate of 8.160 GPixel/s and a texture rate of 32.64 GTexel/s, while the GT 640 has a pixel rate of 7.216 GPixel/s and a texture rate of 28.86 GTexel/s. The FP32 performance is 783.4 GFLOPS for the GT 755M and 692.7 GFLOPS for the GT 640.

Power consumption is another differentiator. The GT 755M has a TDP of 50 W, while the GT 640 has a TDP of 65 W. The GT 755M is more power-efficient despite being faster. The GT 640 also has a suggested PSU of 250 W, while the GT 755M does not list one, which is typical for MXM modules that rely on the laptop's power delivery.

The physical form factor differs as well. The GT 755M is an MXM Module, while the GT 640 is a Single-slot card. The GT 640 has a length of 145 mm (5.7 inches) and display outputs of 1x DVI, 1x HDMI 1.4a, and 1x DisplayPort 1.2. The GT 755M has display outputs that are listed as "Portable Device Dependent," meaning they vary by the laptop design.

The generation and release timing also differ. The GT 755M belongs to the GeForce 700M generation, while the GT 640 belongs to the GeForce 600 generation. The GT 755M was released roughly one year later. The launch MSRP for the GT 640 was 99 USD, while the GT 755M has no recorded launch MSRP, likely because it was an OEM mobile part.

The Verdict

The data in the database shows a clear winner: the NVIDIA GeForce GT 755M is the superior GPU in every recorded metric. It wins both head-to-head benchmarks, has a higher average benchmark score, and offers significantly higher memory bandwidth, compute rates, and clock speeds. The GT 755M achieves this while consuming less power (50 W versus 65 W), which makes it a more efficient part despite being faster.

For users who need maximum compute performance from a mobile GPU, the GT 755M is the obvious choice. Its 50.1% lead in Geekbench Metal and 32.1% lead in Geekbench OpenCL over the GT 640 are substantial margins that would be noticeable in any GPU-accelerated workload. The higher memory bandwidth of 86.40 GB/s versus 28.51 GB/s is particularly important for memory-intensive tasks.

The GT 640, on the other hand, is a desktop card with a different set of trade-offs. It has a lower average benchmark score of 3210, and its nearest rivals in the database include the Intel Arc Pro B60 (3182) and the NVIDIA Quadro P1000 (3163), which it slightly outperforms. It also trails the NVIDIA GeForce 920M (3287) and the NVIDIA GeForce GT 730M (3316) by small margins. The GT 640's single-slot form factor and standard display outputs make it suitable for basic desktop systems, but its DDR3 memory is a clear bottleneck compared to the GDDR5 on the GT 755M.

The choice between these two cards largely depends on the platform. The GT 755M is an MXM module designed for laptops, so it is not a drop-in replacement for a desktop GPU. The GT 640 is a desktop card with a 145 mm length and standard outputs. For a laptop user, the GT 755M is the only option of the two that fits the form factor. For a desktop user, the GT 640 is the relevant part, but the data shows it is a weaker performer.

The percentile data reinforces this hierarchy. The GT 755M sits at the 24th percentile of all GPUs, while the GT 640 sits at the 20th percentile. Neither is a high-end part by modern standards, but the GT 755M is clearly the better performer within this comparison. The GT 755M's nearest rivals in the database are all within a 1.5% range of its average score, which shows it is a competitive mid-range mobile GPU for its time. The GT 640's nearest rivals are also tightly clustered, but at a lower performance level.

In summary, the GT 755M is recommended for anyone seeking a mobile GPU with better compute performance and power efficiency. The GT 640 remains a functional desktop option for basic tasks, but the recorded data shows it is outclassed by the GT 755M in every measurable way. The GT 755M's 50.1% and 32.1% benchmark leads, combined with its higher bandwidth and lower TDP, make it the clear choice for performance-oriented applications. The GT 640 can be considered for simple desktop builds where its single-slot size and standard outputs are advantageous, but its performance ceiling is noticeably lower.