AMD Radeon RX 580 2048SP vs AMD Radeon RX 6600 XT Comparison

The AMD Radeon RX 6600 XT and the AMD Radeon RX 580 2048SP represent two distinct eras of AMD graphics architecture. The data shows a decisive generational leap, with the RX 6600 XT winning all three head-to-head benchmarks by substantial margins. The RX 6600 XT posts an average benchmark score of 24,442, placing it in the 70th percentile of all GPUs, while the RX 580 2048SP averages 23,061, sitting in the 68th percentile. Despite the relatively close average scores, the individual benchmark deltas reveal a massive performance gap in modern workloads, driven by fundamental differences in architecture, process technology, and memory subsystem design.

Head-to-Head Benchmarks

The most extreme discrepancy appears in the Geekbench OpenCL compute test. The RX 6600 XT scores 80,503, which is 171.3% higher than the RX 580 2048SP's 29,668. This result is a direct reflection of the raw compute throughput difference between the two cards. The RX 6600 XT delivers 10.60 TFLOPS of FP32 performance, while the RX 580 2048SP manages only 5.259 TFLOPS. The RX 6600 XT's FP16 performance of 21.21 TFLOPS (2:1 ratio) further underscores its compute advantage, whereas the RX 580 2048SP offers FP16 at the same rate as FP32 (5.259 TFLOPS, 1:1 ratio). This makes the RX 6600 XT more than twice as fast in peak FP32 throughput and four times as fast in FP16 throughput, which explains the enormous OpenCL delta.

In the 3DMark Steel Nomad DX12 test, the RX 6600 XT scores 1,804 against the RX 580 2048SP's 849, a 112.5% advantage. This benchmark stresses modern DirectX 12 features and geometry processing. The RX 6600 XT's RDNA 2.0 architecture with 32 dedicated ray accelerators and DirectX 12 Ultimate (12_2) support gives it a structural advantage over the RX 580 2048SP's GCN 4.0 architecture, which only supports DirectX 12 (12_0). The pixel rate difference is stark: the RX 6600 XT achieves 165.7 GPixel/s versus 41.09 GPixel/s for the RX 580 2048SP, a 4x gap that directly impacts rasterization-heavy scenes.

The Vulkan benchmark shows the smallest, though still decisive, delta. The RX 6600 XT scores 72,417 versus 38,666 for the RX 580 2048SP, an 87.3% advantage. While Vulkan is a lower-level API that can sometimes narrow architectural gaps, the RX 6600 XT still nearly doubles the older card's score. This is consistent with its 331.4 GTexel/s texture rate versus 164.4 GTexel/s for the RX 580 2048SP, and its 64 ROPs versus 32 ROPs. The RX 6600 XT also supports Vulkan 1.4, while the RX 580 2048SP is limited to Vulkan 1.3, which may contribute to better driver optimization in newer titles. Across all three tests, the RX 6600 XT wins 3 out of 3, with the RX 580 2048SP failing to secure a single victory.

Where Each One Wins

The RX 6600 XT wins in every measured category, but the nature of its victories varies by workload. In compute-heavy tasks like OpenCL, the 171.3% lead is overwhelming, driven by the 2x FP32 throughput and the 4x FP16 throughput. This makes the RX 6600 XT the clear choice for GPU-accelerated compute, machine learning inference, and any workload that can leverage FP16 with 2:1 rate. The RX 580 2048SP's 1:1 FP16 ratio means it offers no such acceleration, making it effectively half as capable in these scenarios.

For gaming, the RX 6600 XT's 112.5% lead in 3DMark Steel Nomad DX12 is the more relevant metric. The card's 8 GB of GDDR6 memory on a 128-bit bus delivers 256.0 GB/s of bandwidth, which is 14.3% more than the RX 580 2048SP's 224.0 GB/s from 4 GB of GDDR5 on a 256-bit bus. While the RX 580 2048SP has a wider bus, the RX 6600 XT's higher memory clock (2000 MHz versus 1750 MHz) and newer memory technology compensate entirely. The RX 6600 XT's 32 MB of L3 cache (implied by RDNA 2.0 architecture, though not listed) helps mitigate the narrower bus, but even without that, its raw bandwidth advantage is clear.

The RX 6600 XT also wins decisively in power efficiency. Despite having a TDP of 160 W versus 150 W for the RX 580 2048SP, the RX 6600 XT delivers over 2x the performance in most tests. This translates to roughly double the performance-per-watt. The RX 6600 XT is built on TSMC's 7 nm process with 11,060 million transistors on a 237 mm² die (46.7M transistors per mm²), while the RX 580 2048SP uses GlobalFoundries' 14 nm process with 5,700 million transistors on a 232 mm² die (24.6M transistors per mm²). The RX 6600 XT packs nearly twice the transistors into a similar die area, explaining its efficiency and performance advantage. The RX 580 2048SP's only potential advantage lies in its PCIe 3.0 x16 interface, which offers more lanes than the RX 6600 XT's PCIe 4.0 x8, but the newer standard's higher bandwidth per lane makes this moot in practice.

FAQ

Q: Which card has a higher average benchmark score?

A: The AMD Radeon RX 6600 XT has an average benchmark score of 24,442, while the AMD Radeon RX 580 2048SP averages 23,061. This places the RX 6600 XT in the 70th percentile of all GPUs versus the 68th percentile for the RX 580 2048SP.

Q: How much faster is the RX 6600 XT in the 3DMark Steel Nomad DX12 test?

A: The RX 6600 XT scores 1,804 versus 849 for the RX 580 2048SP, resulting in a 112.5% performance advantage for the RX 6600 XT.

Q: What is the memory configuration difference between the two cards?

A: The RX 6600 XT has 8 GB of GDDR6 memory on a 128-bit bus with 256.0 GB/s bandwidth, while the RX 580 2048SP has 4 GB of GDDR5 memory on a 256-bit bus with 224.0 GB/s bandwidth.

Q: Does the RX 580 2048SP support hardware ray tracing?

A: No. The RX 580 2048SP has no ray tracing cores (rtCores is null in its specification), while the RX 6600 XT includes 32 ray accelerators.

Q: Which card has a higher boost clock?

A: The RX 6600 XT has a boost clock of 2589 MHz, compared to 1284 MHz for the RX 580 2048SP. The RX 6600 XT's base clock of 1968 MHz is also higher than the RX 580 2048SP's boost clock.

Q: What is the transistor count difference?

A: The RX 6600 XT contains 11,060 million transistors on a 237 mm² die, while the RX 580 2048SP contains 5,700 million transistors on a 232 mm² die. The RX 6600 XT achieves a transistor density of 46.7M per mm² versus 24.6M per mm² for the RX 580 2048SP.

Specification Differences

The two cards differ in nearly every core specification. The RX 6600 XT uses a 7 nm process from TSMC, while the RX 580 2048SP uses a 14 nm process from GlobalFoundries. Transistor counts are 11,060 million versus 5,700 million, with die sizes of 237 mm² and 232 mm² respectively. Clock speeds are drastically different: the RX 6600 XT runs at 1968 MHz base and 2589 MHz boost, while the RX 580 2048SP runs at 1168 MHz base and 1284 MHz boost. The RX 6600 XT also has a defined game clock of 2359 MHz, which the RX 580 2048SP lacks.

Memory specifications diverge completely. The RX 6600 XT has 8 GB of GDDR6 at 2000 MHz (16 Gbps effective) on a 128-bit bus, yielding 256.0 GB/s bandwidth. The RX 580 2048SP has 4 GB of GDDR5 at 1750 MHz (7 Gbps effective) on a 256-bit bus, yielding 224.0 GB/s bandwidth. While both cards have 2048 shading units and 128 TMUs, the RX 6600 XT has 64 ROPs versus 32 ROPs for the RX 580 2048SP. The RX 6600 XT includes 32 ray accelerators; the RX 580 2048SP has none.

Performance rates differ substantially: the RX 6600 XT achieves 165.7 GPixel/s and 331.4 GTexel/s, while the RX 580 2048SP achieves 41.09 GPixel/s and 164.4 GTexel/s. FP32 compute is 10.60 TFLOPS versus 5.259 TFLOPS, and FP16 is 21.21 TFLOPS (2:1) versus 5.259 TFLOPS (1:1). The RX 6600 XT has a TDP of 160 W versus 150 W for the RX 580 2048SP, though both use a single 8-pin power connector and suggest a 450 W PSU. The RX 6600 XT uses PCIe 4.0 x8, while the RX 580 2048SP uses PCIe 3.0 x16. Display outputs differ: the RX 6600 XT has 1x HDMI 2.1 and 3x DisplayPort 1.4a, while the RX 580 2048SP has 1x DVI, 1x HDMI 2.0b, and 3x DisplayPort 1.4a. Physical dimensions also vary: the RX 6600 XT is 190 mm long, 110 mm tall, and 40 mm wide, while the RX 580 2048SP is 241 mm long with unspecified height and width.

Architecture Differences

The RX 6600 XT is built on the RDNA 2.0 architecture, part of the Navi II generation (RX 6000 series), using the Navi 23 chip. The RX 580 2048SP uses the GCN 4.0 architecture, part of the Polaris generation (RX 500 series), based on the Polaris 20 chip. This represents a fundamental design shift: RDNA 2.0 is a modern graphics architecture designed for high clock speeds and efficiency, while GCN 4.0 is an older compute-oriented design that prioritizes raw throughput over frequency.

The API support reflects this generational gap. The RX 6600 XT supports DirectX 12 Ultimate (12_2), which includes features like ray tracing and variable rate shading, while the RX 580 2048SP is limited to DirectX 12 (12_0). Both support OpenGL 4.6, but the RX 6600 XT supports Vulkan 1.4 versus Vulkan 1.3 for the RX 580 2048SP. The presence of 32 ray accelerators in the RX 6600 XT enables hardware-accelerated ray tracing, a feature completely absent from the RX 580 2048SP.

The process node difference is critical: 7 nm TSMC versus 14 nm GlobalFoundries. This allows the RX 6600 XT to pack 11,060 million transistors into a 237 mm² die, achieving a density of 46.7M transistors per mm², nearly double the 24.6M per mm² of the RX 580 2048SP. The smaller process also enables the much higher clock speeds (2589 MHz boost versus 1284 MHz). The RX 6600 XT's predecessor is Navi, and its successor is Navi III, while the RX 580 2048SP's predecessor is Arctic Islands and its successor is Vega, illustrating their different lineage paths. The RX 6600 XT was released on 2021-07-29 with a launch MSRP of 379 USD, while the RX 580 2048SP was released on 2018-10-14 with no recorded launch MSRP. Both are end-of-life products, but the RX 6600 XT represents a far more modern and capable design.