NVIDIA GeForce GT 545 vs NVIDIA GeForce GT 640 Comparison

The NVIDIA GeForce GT 545 and NVIDIA GeForce GT 640 represent two distinct evolutionary steps within NVIDIA’s entry-level discrete GPU lineup. The data shows a clear generational shift, with the GT 640 leveraging a newer architecture and manufacturing process to secure a benchmark victory, yet the GT 545 retains certain structural advantages that are worth examining. This analysis breaks down the head-to-head results, architectural divergences, and the practical implications for each card based solely on the provided facts.

Head-to-Head Benchmarks

The benchmark data provides a single direct comparison point between these two cards: the Geekbench OpenCL test. In this test, the NVIDIA GeForce GT 640 scores 3736, while the NVIDIA GeForce GT 545 scores 3594. This yields a deltaPct of -3.8%, meaning the GT 640 outperforms the GT 545 by 3.8% in this specific compute workload. It is a decisive win for the newer card, though the margin is modest rather than transformative.

Looking at the GT 545’s position within its own nearest rivals, its score of 3594 places it just 0.1% behind the NVIDIA RTX 5000 Mobile Ada Generation (3596) and 0.6% behind the NVIDIA GeForce GT 735M (3616). The data also shows it trailing the NVIDIA GeForce GTX 1050 by 1% and the AMD Radeon HD 6770 by 1.5%. This clustering suggests the GT 545 sits at a performance level that is remarkably close to several other cards, with the deltaPct values all within a narrow 1.5% band. The GT 545’s percentile ranking of 21 indicates it outperforms only 21% of all GPUs in the database.

The GT 640, meanwhile, has a more complex benchmark profile, with results across three different API tests. Its OpenCL score of 3736 is its middle result, sitting between a Vulkan score of 3809 and a Metal score of 2086. The Metal score is significantly lower, which indicates that the GT 640’s performance is highly dependent on the API in use, with OpenCL and Vulkan showing much stronger results than Metal. Its average benchmark score across all tests is 3210, which is lower than its OpenCL score due to the inclusion of the weaker Metal result.

In terms of its rivals, the GT 640’s average score of 3210 places it 0.9% ahead of the Intel Arc Pro B60 (3182) and 1.5% ahead of the NVIDIA Quadro P1000 (3163). However, it falls 2.3% behind the NVIDIA GeForce 920M (3287) and 3.2% behind the NVIDIA GeForce GT 730M (3316). The GT 640’s percentile rank of 20 is essentially tied with the GT 545’s 21, showing that despite the newer architecture, both cards occupy a similar low-performance tier in the overall GPU landscape.

When focusing strictly on the head-to-head OpenCL result, the GT 640’s 3.8% lead is the single measurable performance advantage in this matchup. The GT 545 has zero wins in the head-to-head benchmarks, while the GT 640 secures one win. This indicates that for the primary compute workload tested, the GT 640 is the superior card, though the margin is not overwhelming.

Architecture Differences

The most fundamental difference between these two GPUs lies in their underlying architectures. The GT 545 is built on the Fermi 2.0 architecture, using the GF116 chip, while the GT 640 utilizes the Kepler architecture with the GK107 chip. This represents a full generational leap from the GeForce 500 series to the GeForce 600 series.

The manufacturing process highlights a significant shift. The GT 545 is fabricated on a 40 nm process node at TSMC, while the GT 640 uses a more advanced 28 nm process at the same foundry. This process shrink has profound implications. The GT 545’s GF116 chip contains 1,170 million transistors on a die size of 238 mm², yielding a transistor density of 4.9M per mm². In contrast, the GT 640’s GK107 packs 1,270 million transistors into a much smaller 118 mm² die, achieving a transistor density of 10.8M per mm². The data shows that the GT 640 crams over twice as many transistors per square millimeter, a direct result of the denser 28 nm manufacturing.

Shader core counts also differ dramatically. The GT 545 is equipped with 144 shading units, while the GT 640 features 384 shading units. This is a 2.67x increase in raw shader count for the Kepler part. Texture mapping units also increase from 24 on the GT 545 to 32 on the GT 640. Both cards share the same 16 ROPs, indicating a similar capability for final pixel output despite the internal differences.

Memory configurations present a trade-off. The GT 545 has 1536 MB of DDR3 memory on a 192-bit bus, resulting in a bandwidth of 38.40 GB/s. The GT 640 has 2 GB of DDR3 memory but on a narrower 128-bit bus, giving it a lower bandwidth of 28.51 GB/s. The GT 545 therefore has a 34.7% bandwidth advantage, which is a critical factor given the memory-bound nature of many entry-level tasks. The memory clock also differs, with the GT 545 running at 800 MHz (1600 Mbps effective) and the GT 640 at 891 MHz (1782 Mbps effective), though the wider bus on the GT 545 more than compensates for the lower clock speed.

The GT 640 also brings a newer PCIe interface, supporting PCIe 3.0 x16, while the GT 545 is limited to PCIe 2.0 x16. Display outputs differ as well: the GT 545 offers DVI, HDMI 1.3a, and VGA, while the GT 640 provides DVI, HDMI 1.4a, and DisplayPort 1.2. The GT 640 adds Vulkan API support (version 1.2.175), which the GT 545 lacks entirely.

FAQ

Q: Which GPU has a higher raw compute performance in the OpenCL benchmark?

A: The NVIDIA GeForce GT 640 scores 3736 compared to the GT 545’s 3594, giving the GT 640 a 3.8% lead in the Geekbench OpenCL test.

Q: How do the memory bandwidth figures compare between the two cards?

A: The GT 545 has a memory bandwidth of 38.40 GB/s, which is higher than the GT 640’s 28.51 GB/s. This gives the older card a 9.89 GB/s advantage despite the GT 640 having a larger 2 GB memory pool versus 1536 MB on the GT 545.

Q: What is the transistor density difference, and what does it imply?

A: The GT 640, built on a 28 nm process, achieves a transistor density of 10.8M per mm², whereas the GT 545 on a 40 nm process has a density of 4.9M per mm². This means the GT 640 packs more than twice the transistors per area, indicating a more modern and efficient design.

Q: Does the GT 640 support newer graphics APIs than the GT 545?

A: Yes, the GT 640 supports Vulkan version 1.2.175, while the GT 545 has no Vulkan support listed. Both cards support DirectX 12 (11_0) and OpenGL 4.6.

Q: Which card has more shading units, and does that correlate with better performance?

A: The GT 640 has 384 shading units, which is significantly more than the GT 545’s 144. This higher count contributes to the GT 640’s higher FP32 performance of 692.7 GFLOPS compared to the GT 545’s 414.7 GFLOPS, and aligns with its OpenCL benchmark win.

Specification Differences

The following specifications differ between the NVIDIA GeForce GT 545 and the NVIDIA GeForce GT 640:

• Architecture: Fermi 2.0 (GT 545) vs. Kepler (GT 640)
• Process Node: 40 nm (GT 545) vs. 28 nm (GT 640)
• Transistors: 1,170 million (GT 545) vs. 1,270 million (GT 640)
• Die Size: 238 mm² (GT 545) vs. 118 mm² (GT 640)
• Transistor Density: 4.9M / mm² (GT 545) vs. 10.8M / mm² (GT 640)
• Memory Size: 1536 MB (GT 545) vs. 2 GB (GT 640)
• Memory Bus Width: 192 bit (GT 545) vs. 128 bit (GT 640)
• Memory Bandwidth: 38.40 GB/s (GT 545) vs. 28.51 GB/s (GT 640)
• Memory Clock: 800 MHz / 1600 Mbps effective (GT 545) vs. 891 MHz / 1782 Mbps effective (GT 640)
• Shading Units: 144 (GT 545) vs. 384 (GT 640)
• TMUs: 24 (GT 545) vs. 32 (GT 640)
• Pixel Rate: 4.320 GPixel/s (GT 545) vs. 7.216 GPixel/s (GT 640)
• Texture Rate: 17.28 GTexel/s (GT 545) vs. 28.86 GTexel/s (GT 640)
• FP32 Performance: 414.7 GFLOPS (GT 545) vs. 692.7 GFLOPS (GT 640)
• TDP: 70 W (GT 545) vs. 65 W (GT 640)
• Bus Interface: PCIe 2.0 x16 (GT 545) vs. PCIe 3.0 x16 (GT 640)
• Display Outputs: 1x DVI, 1x HDMI 1.3a, 1x VGA (GT 545) vs. 1x DVI, 1x HDMI 1.4a, 1x DisplayPort 1.2 (GT 640)
• Vulkan Support: Not listed (GT 545) vs. 1.2.175 (GT 640)
• Release Date: 2011-05-13 (GT 545) vs. 2012-06-04 (GT 640)
• Launch MSRP: 149 USD (GT 545) vs. 99 USD (GT 640)

Both cards share the same 16 ROPs, 70 W vs 65 W TDP, single-slot width, lack of power connectors, 250 W suggested PSU, and identical 145 mm / 5.7 inches length.

The Verdict

The benchmark data points to the NVIDIA GeForce GT 640 as the overall performance winner in this matchup, securing the sole head-to-head victory with a 3.8% higher OpenCL score. The architecture differences support this outcome: the GT 640’s Kepler architecture on a 28 nm process delivers 384 shading units and 692.7 GFLOPS of FP32 compute, compared to the GT 545’s 144 units and 414.7 GFLOPS. The GT 640 also achieves higher pixel and texture rates, at 7.216 GPixel/s and 28.86 GTexel/s respectively, versus 4.320 GPixel/s and 17.28 GTexel/s on the GT 545.

However, the GT 545 is not without its own merits. Its memory bandwidth of 38.40 GB/s is substantially higher than the GT 640’s 28.51 GB/s, and it carries a wider 192-bit memory bus. For workloads that are heavily memory-bound, the GT 545 could theoretically offer better performance in that specific aspect, though the benchmark data does not provide a direct test of this. The GT 545 also has a slightly higher TDP of 70 W versus 65 W, indicating it draws marginally more power.

The percentile rankings are nearly identical, with the GT 545 at the 21st percentile and the GT 640 at the 20th percentile. This suggests that despite the GT 640’s architectural advantages, both cards ultimately land in the same low-performance tier when compared to the entire GPU market. The GT 640’s average benchmark score of 3210 is actually lower than the GT 545’s average of 3594, but this is misleading because the GT 640’s average includes a weak Metal score of 2086, which drags down its mean. In the OpenCL test, which is the direct comparison, the GT 640 wins.

Where Each One Wins

The NVIDIA GeForce GT 640 wins in compute-heavy scenarios that utilize OpenCL or Vulkan APIs. Its higher shading unit count, faster pixel and texture rates, and superior FP32 performance make it the clear choice for general-purpose compute tasks and modern graphics workloads that can leverage its Kepler architecture. The Vulkan support is a notable addition, enabling compatibility with newer applications that require this API. Its higher memory capacity of 2 GB also provides more headroom for larger textures and datasets compared to the GT 545’s 1536 MB.

The NVIDIA GeForce GT 545 wins in scenarios where memory bandwidth is the critical bottleneck. Its 38.40 GB/s bandwidth over a 192-bit bus is a significant advantage over the GT 640’s 128-bit bus and 28.51 GB/s. This could translate to better performance in older games or applications that rely heavily on memory throughput rather than raw shader compute. The GT 545 also offers a VGA output, which may be beneficial for connecting to legacy displays, while the GT 640 replaces this with a DisplayPort 1.2 connection. For users with older monitors or systems that lack DisplayPort inputs, the GT 545’s output options provide immediate compatibility without needing adapters.