AMD Radeon RX 7900 XT vs NVIDIA Tesla K20Xm Comparison

The NVIDIA Tesla K20Xm and AMD Radeon RX 7900 XT are separated by a decade of GPU architecture, yet the benchmark data reveals a surprisingly narrow overall performance gap. The K20Xm, a Kepler-era compute card from 2012, posts an average benchmark score of 12,625, while the RDNA 3-based RX 7900 XT from 2022 averages 13,745. That places the newer card just 8.9% higher in the aggregate, with the K20Xm sitting at the 52nd percentile of all GPUs and the RX 7900 XT at the 55th. The real story, however, is not the average but the specific workloads where these two diverge dramatically.

Head-to-Head Benchmarks

The only direct benchmark comparison in the data is Geekbench OpenCL, and here the older card wins decisively. The NVIDIA Tesla K20Xm scores 17,215 against the AMD Radeon RX 7900 XT’s 12,756. That is a 35% advantage for the Tesla, a remarkable result given the generational gap. The K20Xm’s OpenCL score is its strongest data point, contributing heavily to its 12,625 average. In contrast, the RX 7900 XT’s OpenCL score of 12,756 is actually below its own average, dragged down by this specific test. This suggests the Kepler architecture’s compute pipelines, designed for scientific workloads, still outperform RDNA 3 in raw OpenCL throughput.

Beyond that single head-to-head, the wider benchmark suites show where each card excels. The RX 7900 XT dominates in modern API tests: it scores 71,068 in Geekbench Vulkan and 29,009 in Passmark G3D. The Tesla K20Xm has no Vulkan score and no Passmark G3D result in the data, so its strengths are concentrated entirely in compute-oriented benchmarks. The RX 7900 XT also posts a 16,828 in Passmark GPU Compute, which is 33% higher than the K20Xm’s average overall score, indicating that in compute tasks outside OpenCL, the newer card pulls ahead. The K20Xm’s nearest rivals in the database—AMD Radeon RX 7600M XT (-0.7%), NVIDIA GeForce GTX 670 (-1.2%), and NVIDIA GeForce GTX 590 (-1.6%)—all sit within a 2% band of its average, showing it clusters with mid-range GPUs from its era. The RX 7900 XT’s nearest rivals include the AMD Radeon RX 9070 XT (+1.5%) and AMD Radeon 660M (-0.5%), placing it in a similar performance tier relative to its contemporaries.

FAQ

Q: Which card has a higher average benchmark score?

A: The AMD Radeon RX 7900 XT averages 13,745, which is 8.9% higher than the NVIDIA Tesla K20Xm’s 12,625. The RX 7900 XT also ranks at the 55th percentile of all GPUs, versus the K20Xm’s 52nd.

Q: Is the Tesla K20Xm faster in any benchmark?

A: Yes, in Geekbench OpenCL the K20Xm scores 17,215, which is 35% higher than the RX 7900 XT’s 12,756. This is the only direct head-to-head test in the data, and the NVIDIA card wins it.

Q: What are the major memory differences?

A: The RX 7900 XT has 20 GB of GDDR6 memory on a 320-bit bus, delivering 800.0 GB/s bandwidth. The K20Xm has 6 GB of GDDR5 on a 384-bit bus, delivering 249.6 GB/s. The RX 7900 XT has over three times the memory capacity and 3.2 times the bandwidth.

Q: How do their compute capabilities compare?

A: The RX 7900 XT offers 51.48 TFLOPS FP32 and 103.0 TFLOPS FP16 (2:1). The K20Xm offers 3.935 TFLOPS FP32 and no FP16 data. The RX 7900 XT has 13 times the FP32 throughput.

Q: Which card has better API support?

A: The RX 7900 XT supports DirectX 12 Ultimate (12_2) and Vulkan 1.4. The K20Xm supports DirectX 12 (11_0) and Vulkan 1.2.175. Both support OpenGL 4.6.

Q: What is the power requirement difference?

A: The RX 7900 XT has a 300 W TDP and suggests a 700 W PSU. The K20Xm has a 235 W TDP and suggests a 550 W PSU. The newer card needs 65 W more power and 150 W more PSU headroom.

The Verdict

The data supports two distinct use cases. For anyone running OpenCL-based compute workloads, the NVIDIA Tesla K20Xm is the clear winner—its 17,215 score beats the RX 7900 XT by 35%, a margin no other benchmark in the pack can match. This is a legacy compute card that still outperforms a modern flagship in one specific API, making it relevant for niche scientific or research tasks that rely on OpenCL.

For everything else, the AMD Radeon RX 7900 XT is the superior choice. It wins the average score comparison (13,745 vs 12,625), holds a higher percentile rank (55th vs 52nd), and offers dramatically better memory capacity (20 GB vs 6 GB) and bandwidth (800.0 GB/s vs 249.6 GB/s). Its Vulkan score of 71,068 and Passmark G3D of 29,009 show strength in modern graphics APIs, while its FP32 throughput of 51.48 TFLOPS is over 13 times the K20Xm’s. The RX 7900 XT also has display outputs (1x HDMI 2.1, 2x DisplayPort 2.1, 1x USB Type-C), making it usable for gaming or workstation display tasks; the K20Xm has no outputs at all.

Specification Differences

The two cards differ in nearly every measurable specification. The K20Xm uses 6 GB of GDDR5 memory on a 384-bit bus, while the RX 7900 XT uses 20 GB of GDDR6 on a 320-bit bus. Bandwidth is 249.6 GB/s versus 800.0 GB/s, favoring AMD by over 3x. The RX 7900 XT has 5,376 shading units, 336 TMUs, and 192 ROPs, compared to the K20Xm’s 2,688 shading units, 224 TMUs, and 48 ROPs. The RX 7900 XT also has 84 ray tracing cores, which the K20Xm lacks entirely. Clock speeds differ: the RX 7900 XT has a base of 1387 MHz and boost of 2394 MHz, while the K20Xm has no listed base or boost clocks, only a memory clock of 1300 MHz (5.2 Gbps effective). The RX 7900 XT’s memory clock is 2500 MHz (20 Gbps effective). Pixel rate is 459.6 GPixel/s for the RX 7900 XT versus 40.99 GPixel/s for the K20Xm. Texture rate is 804.4 GTexel/s versus 164.0 GTexel/s. The RX 7900 XT uses a PCIe 4.0 x16 interface and has display outputs; the K20Xm uses PCIe 3.0 x16 with no outputs. Power connectors are 2x 8-pin for AMD versus none listed for NVIDIA. Dimensions: the RX 7900 XT is 276 mm long, 110 mm tall, and 51 mm wide; the K20Xm is 267 mm long. Both are dual-slot cards.

Architecture Differences

The architectural gap is foundational. The K20Xm uses NVIDIA’s Kepler architecture on a 28 nm TSMC process, packing 7,080 million transistors into a 561 mm² die for a density of 12.6M transistors per mm². The RX 7900 XT uses AMD’s RDNA 3.0 architecture on a 5 nm TSMC process, with 57,700 million transistors in a smaller 529 mm² die, achieving 109.1M transistors per mm²—8.7 times the density. The K20Xm’s chip is GK110, while the RX 7900 XT uses Navi 31 with the codename Plum Bonito. The RX 7900 XT has 84 ray tracing cores, a feature absent from Kepler. Its FP16 throughput is 103.0 TFLOPS with a 2:1 ratio to FP32, whereas the K20Xm has no FP16 data. The RX 7900 XT belongs to the Navi III (RX 7000) generation, preceded by Navi II and followed by Navi IV; the K20Xm is in the Tesla Kepler (Kxx) generation, preceded by Tesla Fermi and followed by Tesla Maxwell. Both are end-of-life products, but the RX 7900 XT supports DirectX 12 Ultimate and Vulkan 1.4, while the K20Xm is limited to DirectX 12 (11_0) and Vulkan 1.2.175.

Where Each One Wins

The NVIDIA Tesla K20Xm wins exclusively in OpenCL compute. Its 17,215 Geekbench OpenCL score is 35% higher than the RX 7900 XT’s, and this is the only benchmark where it leads. This makes it the pick for legacy compute pipelines, scientific simulation, or any software stack that is locked into OpenCL and cannot migrate to Vulkan or modern APIs. Its lower 235 W TDP also means it draws less power than the RX 7900 XT’s 300 W, which could matter in multi-GPU compute racks where thermal density is a concern.

The AMD Radeon RX 7900 XT wins everywhere else. It has a higher average score (13,745 vs 12,625), a better percentile rank (55th vs 52nd), and dominates in modern graphics workloads—its Vulkan score of 71,068 is unmatched by any K20Xm result. Its 20 GB VRAM and 800.0 GB/s bandwidth make it suitable for large datasets or high-resolution textures, while its 51.48 TFLOPS FP32 and 103.0 TFLOPS FP16 positions it for AI inference or compute tasks that leverage FP16. The RX 7900 XT also has display outputs, enabling standard desktop or gaming use, which the K20Xm cannot do. For a builder choosing between these two today, the RX 7900 XT is the general-purpose workhorse; the K20Xm is a specialized tool for one specific benchmark niche.