AMD Radeon 540 vs NVIDIA GeForce GTX 660 Comparison

Head-to-Head Benchmarks

The recorded data shows a decisive victory for the NVIDIA GeForce GTX 660 across both compute benchmarks shared in the database. In the Geekbench OpenCL test, the GTX 660 scores 11,347 against the AMD Radeon 540's 6,184. That is an 83.5% advantage, a massive gap that speaks to the fundamental differences in compute resources between these two cards. The GTX 660 is not just faster here; it is nearly twice as fast, which is a staggering margin for any hardware comparison.

The Vulkan benchmark narrows the gap somewhat, but the outcome remains unchanged. The GTX 660 posts 11,415 while the Radeon 540 reaches 9,162. This 24.6% lead for the NVIDIA card shows that even in a more modern, lower-level API, the older Kepler architecture still holds a substantial edge. The fact that the delta shrinks from 83.5% to 24.6% between OpenCL and Vulkan suggests the Radeon 540's architecture is more efficient per compute unit in newer APIs, but it simply does not have enough raw throughput to overcome the GTX 660's larger allocation of shading units, texture units, and memory bandwidth.

The win count is clean: 2 wins for the GTX 660, 0 for the Radeon 540. There are no mixed results or caveats in the head-to-head data. The average benchmark score across all recorded tests also reflects this hierarchy, with the GTX 660 averaging 9,022 and the Radeon 540 averaging 7,673. The GTX 660 sits at the 45th percentile of all GPUs in the database, while the Radeon 540 sits at the 41st percentile, a modest but meaningful difference in overall standing.

The nearest rival data places the GTX 660 in close company with the NVIDIA TITAN V CEO Edition, which scores 9,037, a delta of only -0.2%. That is a remarkable alignment, showing that the GTX 660's average performance is statistically indistinguishable from a far more exotic product in this specific metric. The Radeon 540, by contrast, is closest to the NVIDIA GeForce GTX 1660 Ti at 7,723, a -0.6% delta, and the AMD Radeon Pro WX 3100 at 7,580, a 1.2% delta. These rival positions reinforce that the GTX 660 competes in a higher performance tier overall, despite being several years older.

Architecture Differences

The fundamental distinction begins with the manufacturing process and the underlying chip design. The GTX 660 uses the GK106 chip built on a 28 nm process at TSMC, while the Radeon 540 uses the Lexa chip on a 14 nm process at GlobalFoundries. The newer node gives AMD a density advantage: 21.4M transistors per mm² versus 11.5M for the NVIDIA chip. However, the GTX 660's die is larger at 221 mm² versus 103 mm², and it packs more total transistors at 2,540 million versus 2,200 million. The density numbers reveal that AMD's architecture is more compact, but NVIDIA's larger die allows for more functional blocks.

The compute core counts tell the performance story. The GTX 660 has 960 shading units, 80 texture mapping units, and 24 ROPs. The Radeon 540 has 384 shading units, 24 TMUs, and 16 ROPs. That means the GTX 660 has 2.5 times the shader count and over 3 times the texture unit count. The pixel rate is 20.64 GPixel/s for the GTX 660 versus 18.93 GPixel/s for the Radeon 540, a closer margin that reflects the Radeon's higher clock potential on the newer node. The texture rate tells a different story: 82.56 GTexel/s versus 28.39 GTexel/s, a 2.9x difference that directly explains the OpenCL benchmark gap.

Memory is perhaps the most striking architectural divergence. The GTX 660 has 2 GB of GDDR5 on a 192-bit bus, yielding 144.2 GB/s of bandwidth. The Radeon 540 has just 1024 MB of GDDR5 on a 32-bit bus, yielding a mere 24.00 GB/s. That is a 6x difference in bandwidth, an enormous gulf that will bottleneck any memory-intensive workload. The GTX 660's memory clock is 1502 MHz (6 Gbps effective), nearly identical to the Radeon 540's 1500 MHz (6 Gbps effective), but the bus width difference makes the effective throughput incomparable.

The floating-point output reflects the shader and clock differences. The GTX 660 delivers 1.981 TFLOPS of FP32, while the Radeon 540 delivers 908.5 GFLOPS. The Radeon 540 does match its FP32 output with FP16 at 908.5 GFLOPS on a 1:1 basis, but the GTX 660 has no recorded FP16 capability. The API support also differs: the GTX 660 supports DirectX 12 (11_0) while the Radeon 540 supports DirectX 12 (12_0), and the Radeon supports Vulkan 1.3 versus the GTX 660's Vulkan 1.2.175. The Radeon 540 is the more modern API implementation, but the GTX 660's raw hardware resources outweigh that advantage.

FAQ

Q: Which card has higher memory bandwidth?

A: The NVIDIA GeForce GTX 660 has 144.2 GB/s of bandwidth, while the AMD Radeon 540 has 24.00 GB/s. The GTX 660 achieves this with a 192-bit bus and 2 GB of GDDR5, compared to the Radeon 540's 32-bit bus and 1024 MB of GDDR5.

Q: How does the compute performance compare in OpenCL?

A: The GTX 660 scores 11,347 in Geekbench OpenCL, which is 83.5% higher than the Radeon 540's 6,184. This is the largest performance gap recorded between the two cards.

Q: Does the Radeon 540 have a lower power requirement?

A: Yes, the Radeon 540 has a 50 W TDP and requires no power connectors, with a suggested PSU of 250 W. The GTX 660 has a 140 W TDP, requires one 6-pin connector, and suggests a 300 W PSU.

Q: Which card supports newer graphics APIs?

A: The AMD Radeon 540 supports DirectX 12 (12_0) and Vulkan 1.3, while the NVIDIA GeForce GTX 660 supports DirectX 12 (11_0) and Vulkan 1.2.175. The Radeon 540 also has FP16 support at 1:1 ratio, which the GTX 660 lacks.

Q: What are the physical size differences?

A: The GTX 660 is 241 mm (9.5 inches) long and is a dual-slot card, while the Radeon 540 is a single-slot card with no recorded length, height, or width dimensions.

Q: Which card has a higher average benchmark score?

A: The GTX 660 has an average benchmark score of 9,022, placing it at the 45th percentile of all GPUs. The Radeon 540 averages 7,673, placing it at the 41st percentile.

Specification Differences

The two cards differ across nearly every specification category. The process node is 28 nm for the GTX 660 versus 14 nm for the Radeon 540. Transistor count is 2,540 million versus 2,200 million, and die size is 221 mm² versus 103 mm². Transistor density is 11.5M per mm² versus 21.4M per mm².

The shading units differ dramatically: 960 versus 384. Texture units are 80 versus 24, and ROPs are 24 versus 16. The pixel rate is 20.64 GPixel/s versus 18.93 GPixel/s, and the texture rate is 82.56 GTexel/s versus 28.39 GTexel/s. FP32 output is 1.981 TFLOPS versus 908.5 GFLOPS, with the Radeon 540 adding FP16 at 908.5 GFLOPS.

Memory size is 2 GB versus 1024 MB, both using GDDR5. Bus width is 192-bit versus 32-bit, and bandwidth is 144.2 GB/s versus 24.00 GB/s. The TDP is 140 W versus 50 W. Slot width is dual-slot versus single-slot. Power connectors are 1x 6-pin versus none. Suggested PSU is 300 W versus 250 W. Bus interface is PCIe 3.0 x16 versus PCIe 3.0 x8.

Display outputs differ as well: 2x DVI, 1x HDMI 1.4a, 1x DisplayPort 1.2 versus 2x DisplayPort 1.4a. The GTX 660 has a launch MSRP of 229 USD, while the Radeon 540 has no recorded launch MSRP. Release dates are September 2012 for the GTX 660 and April 2017 for the Radeon 540. The GTX 660's predecessor is the GeForce 500 series and successor is the GeForce 700 series, while the Radeon 540's predecessor is Arctic Islands and successor is Vega.

Where Each One Wins

The GTX 660 wins every recorded benchmark, so the use-case split is heavily one-sided. The GTX 660 is the clear choice for any workload that depends on memory bandwidth, given its 144.2 GB/s versus 24.00 GB/s. That advantage will manifest in high-resolution textures, large data sets, and any compute task that streams data through memory. The 83.5% OpenCL lead reinforces this: the GTX 660 can handle general-purpose compute workloads with far greater throughput, thanks to its 960 shading units and 80 TMUs.

The GTX 660 also wins for anyone needing a more flexible display configuration, offering 2x DVI, HDMI 1.4a, and DisplayPort 1.2. The Radeon 540 limits you to 2x DisplayPort 1.4a, which is modern but less versatile for legacy monitors or mixed setups. The GTX 660's PCIe 3.0 x16 interface also provides twice the lane bandwidth of the Radeon 540's x8 interface, which matters if the card is used in a system with other bandwidth-hungry devices.

The Radeon 540 does have its own advantages, though they do not translate to benchmark wins. Its 50 W TDP and lack of power connectors make it a drop-in solution for low-power systems, where the GTX 660's 140 W TDP and 6-pin connector could be problematic. The single-slot form factor also saves space in compact chassis, and the Radeon 540's support for Vulkan 1.3 and DirectX 12 (12_0) means it is better prepared for the latest API-level features, even if it lacks the horsepower to exploit them fully.

For gaming, the data suggests the GTX 660 is the stronger card, but with a caveat. The 24.6% Vulkan lead shows it is still faster in modern APIs, but the Radeon 540's newer architecture and FP16 support could be relevant for specific compute workloads that leverage reduced precision. The Radeon 540's higher transistor density (21.4M per mm²) also indicates a more efficient design per unit area, though the GTX 660's larger die compensates with raw resources.

The Verdict

The data is unambiguous: the NVIDIA GeForce GTX 660 is the superior card for performance. It wins both head-to-head benchmarks, has a higher average score (9,022 versus 7,673), and sits in a higher percentile (45th versus 41st). Its 83.5% OpenCL advantage and 24.6% Vulkan advantage are not marginal; they are decisive. Anyone who needs raw compute throughput, higher memory bandwidth, or better texture processing should choose the GTX 660 without hesitation.

The GTX 660 also offers more memory (2 GB versus 1024 MB) and a wider bus (192-bit versus 32-bit), which makes it more future-proof for increasingly memory-hungry workloads. Its dual-slot form factor and 140 W TDP are the only real drawbacks, but those are physical constraints, not performance limitations. The launch MSRP of 229 USD indicates it was positioned as a mainstream card, and the benchmark data confirms it still holds its own against much newer hardware.

The AMD Radeon 540 is not without merit, but its value lies in niche scenarios. The 50 W TDP, single-slot design, and lack of power connectors make it ideal for low-power or space-constrained systems. Its support for Vulkan 1.3 and DirectX 12 (12_0) means it is architecturally more modern, and its 1:1 FP16 ratio could serve specific compute tasks. But for anyone choosing between these two based on performance, the GTX 660 wins on every recorded metric.

The verdict is simple: pick the GTX 660 for performance, pick the Radeon 540 for efficiency and compactness. The data does not support any other conclusion. The GTX 660's dominance in both OpenCL and Vulkan, combined with its vastly superior memory subsystem, makes it the only reasonable choice for compute or gaming workloads. The Radeon 540's only real advantages are power draw and physical size, which are relevant but secondary to raw capability.