AMD Radeon RX 6400 vs NVIDIA Quadro K4000M Comparison

The AMD Radeon RX 6400 and NVIDIA Quadro K4000M are separated by a decade of GPU architecture, and the benchmark data reflects a decisive generational gap. In the only shared test, the Geekbench OpenCL benchmark, the RX 6400 delivers a score of 32,011 against the K4000M’s 5,986, a 434.8% advantage. This single result dominates the head-to-head, but the underlying specifications reveal why the newer card is in a different performance class entirely.

Head-to-Head Benchmarks

The sole direct comparison available is the Geekbench OpenCL compute test. The AMD Radeon RX 6400 scores 32,011, while the NVIDIA Quadro K4000M scores 5,986. This represents a 434.8% delta, meaning the RX 6400 is nearly 4.5 times faster in this compute workload. The result is not close; it is a complete sweep for the AMD part, with the RX 6400 claiming the only win in the head-to-head comparison.

The magnitude of this victory is contextualized by their average benchmark scores. The RX 6400 has an average benchmark score of 6,001, placing it at the 35th percentile of all GPUs. The K4000M’s average score is 5,986, at the 34th percentile. Despite the massive OpenCL gap, their average scores are nearly identical, differing by only 0.3%. This paradox occurs because the RX 6400 has a broader benchmark suite, including several Passmark tests where it scores very low (e.g., 30 in DirectX 12, 54 in DirectX 10), which drags its average down to the K4000M’s level.

In terms of nearest rivals, the RX 6400’s average score of 6,001 is exactly 0% different from the NVIDIA GeForce GTX 770M’s 6,000. It is also 0.1% ahead of the NVIDIA RTX PRO 6000 Blackwell Server’s 5,996 and 0.2% ahead of the AMD FirePro W4100’s 5,987. The K4000M’s 5,986 average score is 0% different from the AMD FirePro W4100’s 5,987, 0.1% behind the NVIDIA Quadro K4000’s 5,982, and 0.2% behind the RTX PRO 6000 Blackwell Server’s 5,996. The data shows these two cards are statistical peers in aggregate performance, even though their architectural approaches differ profoundly.

Architecture Differences

The RX 6400 is built on TSMC’s 6 nm process node using the RDNA 2.0 architecture, while the K4000M uses a 28 nm process with NVIDIA’s Kepler architecture. This process shrink is fundamental: the RX 6400 packs 5,400 million transistors into a 107 mm² die, achieving a transistor density of 50.5 million transistors per mm². The K4000M has 3,540 million transistors on a 294 mm² die, with a density of just 12.0 million transistors per mm². The RX 6400’s density is over four times higher, enabling far more compute per square millimeter.

Clock speeds tell a similar story. The RX 6400 has a base clock of 1923 MHz and a boost clock of 2321 MHz, with a game clock of 2039 MHz. The K4000M is locked at a base and boost clock of 601 MHz. This clock advantage, combined with the newer architecture, explains the RX 6400’s massive lead in raw throughput. The RX 6400 also features 12 dedicated ray tracing cores, which the K4000M lacks entirely, reflecting the modern focus on real-time ray tracing workloads.

Memory subsystems diverge as well. The RX 6400 uses 4 GB of GDDR6 memory on a 64-bit bus, delivering 128.0 GB/s of bandwidth. The K4000M uses 4 GB of GDDR5 on a 256-bit bus, but only manages 89.60 GB/s due to its lower 700 MHz memory clock (2.8 Gbps effective). The RX 6400’s narrower bus is more than compensated by its higher memory frequency, resulting in 43% more bandwidth. Additionally, the RX 6400 supports PCIe 4.0 x4, while the K4000M uses an MXM-B (3.0) interface, which is a mobile-specific form factor.

Compute capabilities are starkly different. The RX 6400 offers 3.565 TFLOPS of FP32 performance and 7.130 TFLOPS of FP16 (2:1 ratio), alongside pixel and texture rates of 74.27 GPixel/s and 111.4 GTexel/s, respectively. The K4000M provides 1,153.9 GFLOPS (1.154 TFLOPS) of FP32, with pixel and texture rates of 12.02 GPixel/s and 48.08 GTexel/s. The RX 6400 is over three times faster in FP32 and over six times faster in pixel fill rate. The K4000M has no FP16 capability listed, while the RX 6400 supports DirectX 12 Ultimate (12_2) and Vulkan 1.4; the K4000M is limited to DirectX 12 (11_0) and Vulkan 1.2.175.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The AMD Radeon RX 6400 has an average benchmark score of 6,001, which is 0.3% higher than the NVIDIA Quadro K4000M’s 5,986. This places the RX 6400 at the 35th percentile of all GPUs, while the K4000M sits at the 34th percentile.

Q: How significant is the difference in the Geekbench OpenCL test?

A: The RX 6400 scores 32,011, which is 434.8% higher than the K4000M’s 5,986. This is the only shared benchmark, and the RX 6400 wins it decisively.

Q: What are the memory specifications of each card?

A: The RX 6400 has 4 GB of GDDR6 memory on a 64-bit bus with 128.0 GB/s bandwidth. The K4000M also has 4 GB of memory, but it is GDDR5 on a 256-bit bus with 89.60 GB/s bandwidth.

Q: How do their power requirements compare?

A: The RX 6400 has a TDP of 53 W and requires a 250 W suggested PSU. The K4000M has a TDP of 100 W, with no suggested PSU listed because it is an MXM module.

Q: Do both cards support ray tracing?

A: No. The RX 6400 has 12 dedicated ray tracing cores, while the K4000M has no ray tracing cores listed.

Q: What is the process node difference?

A: The RX 6400 is fabricated on a 6 nm process, while the K4000M uses a 28 nm process. Both are made by TSMC, but the RX 6400’s die is 107 mm², whereas the K4000M’s is 294 mm².

Specification Differences

The following specifications differ between the two cards:

• Process Node: 6 nm (RX 6400) vs 28 nm (K4000M)
• Transistors: 5,400 million vs 3,540 million
• Die Size: 107 mm² vs 294 mm²
• Transistor Density: 50.5M / mm² vs 12.0M / mm²
• Base Clock: 1923 MHz vs 601 MHz
• Boost Clock: 2321 MHz vs 601 MHz
• Game Clock: 2039 MHz (RX 6400 only)
• Memory Clock: 2000 MHz / 16 Gbps effective vs 700 MHz / 2.8 Gbps effective
• Memory Type: GDDR6 vs GDDR5
• Memory Bus Width: 64 bit vs 256 bit
• Memory Bandwidth: 128.0 GB/s vs 89.60 GB/s
• Shading Units: 768 vs 960
• TMUs: 48 vs 80
• ROPs: 32 (same)
• RT Cores: 12 vs 0
• Pixel Rate: 74.27 GPixel/s vs 12.02 GPixel/s
• Texture Rate: 111.4 GTexel/s vs 48.08 GTexel/s
• FP32 Performance: 3.565 TFLOPS vs 1,153.9 GFLOPS
• FP16 Performance: 7.130 TFLOPS (2:1) vs null
• TDP: 53 W vs 100 W
• Slot Width: Single-slot vs MXM Module
• Suggested PSU: 250 W vs null
• Bus Interface: PCIe 4.0 x4 vs MXM-B (3.0)
• Display Outputs: 1x HDMI 2.1, 1x DisplayPort 1.4a vs Portable Device Dependent
• DirectX Support: 12 Ultimate (12_2) vs 12 (11_0)
• Vulkan Support: 1.4 vs 1.2.175
• Release Date: 2022-01-18 vs 2012-05-31
• Launch MSRP: 159 USD vs null (RX 6400 only)
• Generation: Navi II (RX 6000) vs Quadro Kepler-M (Kx000M)

The Verdict

The data is unambiguous: the AMD Radeon RX 6400 is the superior performer for any modern workload. Its 434.8% lead in Geekbench OpenCL is the only direct comparative metric, and it wins that test outright. The RX 6400’s architectural advantages—6 nm process, RDNA 2.0, 12 RT cores, and 128.0 GB/s bandwidth—make it a far more capable GPU for compute, gaming, and content creation. The K4000M’s 28 nm Kepler architecture is antiquated, offering less than a third of the FP32 throughput and a sixth of the pixel fill rate.

However, the average benchmark scores are nearly tied (6,001 vs 5,986), which suggests that in a limited set of legacy or specific workloads, the K4000M might not be entirely embarrassed. The K4000M’s 960 shading units and 80 TMUs are higher than the RX 6400’s 768 and 48, respectively, which could indicate some theoretical advantage in older, shader-bound applications. Yet, the K4000M’s 601 MHz clock speed cripples this potential. The RX 6400’s boost clock of 2321 MHz is nearly four times higher, overwhelming the K4000M’s core count advantage.

For a user choosing between these two today, the RX 6400 is the only rational choice for any task requiring modern API support (DirectX 12 Ultimate, Vulkan 1.4) or ray tracing. The K4000M is a legacy mobile part, end-of-life since its 2012 release, and is only relevant for maintaining old systems. The RX 6400 also has a 53 W TDP versus the K4000M’s 100 W, making it more power-efficient despite its vastly higher performance. The verdict is clear: the RX 6400 wins on every meaningful performance metric, with the K4000M holding only a theoretical advantage in raw shading unit count that the clock speeds render irrelevant.

Where Each One Wins

AMD Radeon RX 6400:

The RX 6400 wins decisively in compute-heavy workloads, as shown by its 32,011 Geekbench OpenCL score versus 5,986. It is the clear choice for any modern gaming, given its DirectX 12 Ultimate support and 12 RT cores, which enable hardware-accelerated ray tracing that the K4000M cannot perform. Its 128.0 GB/s memory bandwidth and 3.565 TFLOPS FP32 performance make it suitable for content creation and GPU-accelerated tasks. The 6 nm process and 53 W TDP also make it far more power-efficient, ideal for compact or low-power builds. Its 1x HDMI 2.1 and 1x DisplayPort 1.4a outputs provide modern display connectivity.

NVIDIA Quadro K4000M:

The K4000M’s advantages are limited to its specification sheet. It has 960 shading units and 80 TMUs, which are higher than the RX 6400’s counts, and a 256-bit memory bus, which is four times wider. In theory, these could benefit older, single-threaded or texture-bound applications that do not scale with clock speed. Its MXM-B (3.0) form factor is designed for mobile workstations, making it the only choice for upgrading a legacy laptop with that specific interface. However, its 601 MHz clock and 89.60 GB/s bandwidth mean it cannot translate these advantages into competitive performance in any benchmark or modern workload. The K4000M wins only in scenarios where the RX 6400 cannot physically be installed due to form factor constraints.