AMD Radeon R9 M390X vs NVIDIA Tesla K40c Comparison

The AMD Radeon R9 M390X and NVIDIA Tesla K40c represent two very different approaches to GPU design from the same 28 nm era, both now end-of-life. The M390X is a mobile-oriented part from AMD’s GCN 3.0 generation, while the K40c is a compute-focused accelerator from NVIDIA’s Kepler line. The recorded data shows a clear split: the AMD card leads in one benchmark, while the NVIDIA card offers a different performance profile. The database places the R9 M390X at the 66th percentile among all GPUs, with an average benchmark score of 20662, while the Tesla K40c sits at the 61st percentile with an average score of 17468. That difference of roughly 18% in average score is significant, but the specifics of each card’s strengths require closer examination.

Head-to-Head Benchmarks

The head-to-head comparison between these two GPUs is not straightforward because they were tested under different benchmark suites. The AMD Radeon R9 M390X has two recorded scores: 24373 in Geekbench Metal and 16951 in Geekbench Vulkan. The NVIDIA Tesla K40c has a single recorded score: 17468 in Geekbench OpenCL. There are no direct head-to-head benchmark entries where both cards ran the same test, so the comparison relies on aggregate scores and relative performance against other GPUs.

Looking at the average benchmark scores, the R9 M390X achieves 20662, which is 3194 points higher than the Tesla K40c’s 17468. That translates to the AMD card being roughly 18% ahead in average performance. However, this average masks the fact that the M390X’s two scores are far apart: its Metal score of 24373 is substantially higher than its Vulkan score of 16951. The Vulkan result is actually below the K40c’s OpenCL score of 17468, meaning the AMD card’s advantage comes entirely from its Metal performance. This suggests the M390X is particularly well optimized for Apple’s Metal API, which is consistent with its mobile and portable device orientation.

The percentile rankings reinforce this picture. The R9 M390X sits at the 66th percentile among all GPUs, while the K40c sits at the 61st percentile. In the database’s nearest rivals list, the M390X is compared to the AMD Radeon RX 5600 XT (average score 20713, delta of -0.2%), the Intel Arc A750 (20582, +0.4%), the Intel Arc B570 (20556, +0.5%), and the NVIDIA GeForce RTX 3070 Mobile (20534, +0.6%). These deltas show that the M390X is essentially neck-and-neck with modern midrange GPUs, within 0.6% of all four rivals. That is remarkable for a card released in 2015, as it suggests the M390X’s Metal-optimized performance keeps it competitive with much newer hardware.

The Tesla K40c, by contrast, has nearest rivals that are all slightly above it: the AMD Radeon Pro 460 (17509, -0.2%), the AMD Radeon Pro 560 (17551, -0.5%), the AMD Radeon 780M (17588, -0.7%), and the NVIDIA GeForce RTX 4060 (17639, -1%). The K40c is within 1% of all these rivals, which means its OpenCL performance is still in the same league as some modern integrated and entry-level discrete GPUs. The negative deltas indicate that each rival scores slightly higher, so the K40c is marginally behind all four.

Breaking down the individual scores, the M390X’s Metal result of 24373 is its strongest showing, beating the K40c’s OpenCL score by 6905 points, or about 40%. That is a substantial margin. Conversely, the M390X’s Vulkan score of 16951 trails the K40c’s OpenCL score by 517 points, or about 3%. So while the AMD card wins the overall average, the NVIDIA card actually outperforms one of the AMD card’s two recorded benchmark types. This indicates that the K40c’s compute performance, as measured by OpenCL, is not far behind the M390X’s Vulkan performance, but the AMD card’s Metal advantage is decisive.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon R9 M390X has an average benchmark score of 20662, while the NVIDIA Tesla K40c has an average score of 17468. The M390X leads by 3194 points, placing it at the 66th percentile compared to the K40c’s 61st percentile.

Q: How does the R9 M390X compare to its nearest rivals?

A: The R9 M390X is within 0.6% of all four nearest rivals in the database. Specifically, it trails the AMD Radeon RX 5600 XT by 0.2%, but leads the Intel Arc A750 by 0.4%, the Intel Arc B570 by 0.5%, and the NVIDIA GeForce RTX 3070 Mobile by 0.6%.

Q: What is the Tesla K40c’s position relative to its nearest rivals?

A: The Tesla K40c trails all four of its nearest rivals. It is 0.2% behind the AMD Radeon Pro 460, 0.5% behind the AMD Radeon Pro 560, 0.7% behind the AMD Radeon 780M, and 1% behind the NVIDIA GeForce RTX 4060.

Q: Does the R9 M390X outperform the K40c in every benchmark?

A: No. The R9 M390X scores 24373 in Geekbench Metal, which is higher than the K40c’s 17468 in Geekbench OpenCL. However, the R9 M390X scores only 16951 in Geekbench Vulkan, which is lower than the K40c’s OpenCL score. So the AMD card wins in Metal but loses when comparing its Vulkan result to the NVIDIA card’s OpenCL result.

Q: What memory configurations do the two cards have?

A: The R9 M390X has 4 GB of GDDR5 memory on a 256-bit bus, providing 160.0 GB/s of bandwidth. The Tesla K40c has 12 GB of GDDR5 memory on a 384-bit bus, providing 288.4 GB/s of bandwidth. The K40c has three times the memory capacity and nearly double the bandwidth.

Q: Which card has a higher transistor count?

A: The NVIDIA Tesla K40c has 7,080 million transistors on a 561 mm² die, while the AMD Radeon R9 M390X has 5,000 million transistors on a 366 mm² die. The K40c has about 42% more transistors and a larger die size.

The Verdict

The data points to different users for each card. The AMD Radeon R9 M390X is the better choice for anyone relying on Metal-based workloads, given its 24373 Metal score that far exceeds the K40c’s overall performance. Its average benchmark score of 20662 also places it above the K40c, and its percentile ranking of 66 versus 61 confirms that it is the stronger performer in the database’s aggregate metrics. The M390X’s nearest rivals include modern GPUs like the Intel Arc A750 and RTX 3070 Mobile, with deltas under 1%, which indicates that this 2015 mobile chip still competes with much newer hardware in the recorded tests.

The NVIDIA Tesla K40c, on the other hand, is the better choice for scenarios that require massive memory capacity or raw compute throughput in OpenCL. Its 12 GB of GDDR5 memory and 288.4 GB/s bandwidth are far superior to the M390X’s 4 GB and 160.0 GB/s. Its OpenCL score of 17468, while lower than the M390X’s average, is still competitive, sitting within 1% of modern GPUs like the Radeon 780M and RTX 4060. The K40c also has a much higher transistor count and larger die, which historically suggests stronger compute capabilities for professional workloads, though the database only records OpenCL performance.

For a general user comparing these two, the M390X wins on average performance and percentile ranking. For a user specifically working with OpenCL or needing large memory buffers, the K40c’s specifications make it attractive despite its lower average score. The M390X is the better all-rounder in the recorded data, while the K40c is a specialized tool with distinct advantages in memory and raw compute resources.

Specification Differences

The two cards differ across nearly every specification category. The R9 M390X uses the Amethyst chip with GCN 3.0 architecture, while the K40c uses the GK180 chip with Kepler architecture. The M390X has 2048 shading units, 128 texture mapping units, and 32 ROPs, while the K40c has 2880 shading units, 240 TMUs, and 48 ROPs. The K40c leads in all three counts, with 40% more shading units, 87.5% more TMUs, and 50% more ROPs.

Clock speeds also differ. The M390X has no recorded base or boost clock, but its memory runs at 1250 MHz (5 Gbps effective). The K40c has a base clock of 745 MHz and a boost clock of 876 MHz, with memory at 1502 MHz (6 Gbps effective). The K40c’s memory clock is higher in both raw MHz and effective data rate.

Memory capacity and bandwidth are major differentiators. The M390X has 4 GB of GDDR5 on a 256-bit bus, yielding 160.0 GB/s. The K40c has 12 GB of GDDR5 on a 384-bit bus, yielding 288.4 GB/s. That is 8 GB more capacity and 80% more bandwidth.

Power and physical specifications also differ significantly. The M390X has a TDP of 75 W, is an MXM Module with no power connectors, and has portable device dependent display outputs. The K40c has a TDP of 245 W, is a dual-slot card requiring 1x 6-pin plus 1x 8-pin power connectors, and has no display outputs. The K40c also has a suggested PSU of 550 W and a length of 267 mm (10.5 inches), while the M390X has no recorded dimensions.

Architecture Differences

The architectural divide is substantial. The R9 M390X is built on GCN 3.0, AMD’s third-generation Graphics Core Next design, fabricated on a 28 nm process at TSMC. It uses the Amethyst chip with 5,000 million transistors on a 366 mm² die, giving a transistor density of 13.7 million per square millimeter. The K40c uses NVIDIA’s Kepler architecture, also on 28 nm at TSMC, but with the GK180 chip containing 7,080 million transistors on a 561 mm² die, for a density of 12.6 million per square millimeter. The K40c has more transistors and a larger die, but slightly lower transistor density.

The M390X supports DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.2.170. The K40c supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175. The DirectX version difference is notable: the M390X supports feature level 12_0, while the K40c only reaches 11_0. This means the AMD card is more capable for modern DirectX 12 titles, while the NVIDIA card is limited to DirectX 11-level features. Both cards support OpenGL 4.6, and the Vulkan versions are nearly identical, with the K40c at 1.2.175 and the M390X at 1.2.170.

The M390X has a 1:1 FP16 to FP32 ratio, with both at 2.961 TFLOPS. The K40c has no recorded FP16 performance, but its FP32 is 5.046 TFLOPS, which is 70% higher than the M390X. Pixel rate and texture rate also favor the K40c: it delivers 52.56 GPixel/s versus 23.14 GPixel/s, and 210.2 GTexel/s versus 92.54 GTexel/s. The K40c’s compute throughput is clearly superior on paper, though the benchmark data shows the M390X achieving a higher average score, likely due to API-specific optimizations.

Where Each One Wins

The AMD Radeon R9 M390X wins in the aggregate benchmark comparison. Its average score of 20662 is 3194 points higher than the K40c’s 17468, and its 66th percentile ranking beats the K40c’s 61st. The M390X’s Geekbench Metal score of 24373 is its standout result, exceeding the K40c’s best recorded score by over 6900 points. This makes the M390X the clear winner for any workload that leverages Metal, such as macOS-based applications or Apple ecosystem tasks. The M390X also wins in efficiency, with a 75 W TDP versus the K40c’s 245 W, making it far more suitable for portable or power-constrained systems. Its MXM module form factor and lack of power connectors further emphasize its mobile design intent.

The NVIDIA Tesla K40c wins on raw compute specifications. Its 5.046 TFLOPS FP32 performance is 70% higher than the M390X’s 2.961 TFLOPS. Its pixel rate of 52.56 GPixel/s and texture rate of 210.2 GTexel/s are both more than double the M390X’s respective figures. The K40c also wins decisively on memory: 12 GB versus 4 GB, and 288.4 GB/s versus 160.0 GB/s. For workloads that require large datasets in memory, such as scientific computing or data processing, the K40c’s memory advantage is critical. Its OpenCL score of 17468, while lower than the M390X’s average, still beats the M390X’s Vulkan score of 16951, so it wins in that specific comparison.

The M390X wins where modern API support matters. Its DirectX 12 (12_0) support is a full feature level above the K40c’s 11_0, making it the better choice for contemporary gaming or graphics applications. The M390X also has display outputs, whereas the K40c has none, so only the AMD card can drive a monitor directly. The K40c wins where compute density and memory capacity are paramount, but the M390X wins on overall benchmark scores, efficiency, and API compatibility. Each card has a clear domain: the M390X for general graphics and Metal-based performance, the K40c for heavy compute and large memory footprints.