AMD Radeon Pro 555X vs AMD Radeon RX 580 Comparison

The AMD Radeon Pro 555X and AMD Radeon RX 580 are both built on AMD’s GCN 4.0 architecture, but they occupy completely different segments of the GPU market. The Pro 555X is a mobile integrated graphics processor designed for professional laptops, while the RX 580 is a dual-slot desktop add-in card aimed at mainstream gaming. Benchmark data shows the RX 580 dominates across every shared test, with the Pro 555X trailing by margins between 66.3% and 71.5% depending on the API. The RX 580 also carries a 53rd percentile rank among all GPUs, versus 54th for the Pro 555X, indicating that despite its massive performance lead, the desktop card sits in a similar overall performance bracket when considering the entire GPU landscape.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon Pro 555X has an average benchmark score of 13321, while the AMD Radeon RX 580 averages 12928. Despite the RX 580 winning every head-to-head test, the Pro 555X edges out the desktop card in aggregate scoring because of the specific benchmark mix.

Q: How large is the performance gap in Geekbench Metal?

A: The RX 580 scores 45235 in Geekbench Metal versus 14479 for the Pro 555X, a difference of 68%. This is the smallest relative gap among the three shared benchmarks, but still represents a massive performance advantage for the desktop GPU.

Q: What is the transistor count difference between the two chips?

A: The RX 580’s Polaris 20 chip contains 5,700 million transistors, nearly double the 3,000 million found in the Pro 555X’s Polaris 21. The die size also scales accordingly, with Polaris 20 measuring 232 mm² versus 123 mm² for Polaris 21.

Q: Which GPU has a higher memory bandwidth?

A: The RX 580 offers 256.0 GB/s of bandwidth through a 256-bit bus and 8 GB of GDDR5 memory. The Pro 555X provides 94.08 GB/s via a 128-bit bus and 4 GB of GDDR5, meaning the desktop card delivers roughly 2.7 times the memory throughput.

Q: Are both GPUs the same architecture and process node?

A: Yes, both use GCN 4.0 architecture and are manufactured on a 14 nm process at GlobalFoundries. They also share the same API support, including DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3.

Q: What is the power draw difference between the two?

A: The Pro 555X has a TDP of 75 W and requires no power connectors, while the RX 580 draws 185 W and needs a single 8-pin connector. The desktop card also suggests a 450 W power supply, whereas the mobile chip uses none.

Architecture Differences

Both GPUs are built on GCN 4.0, but the silicon underneath is starkly different. The Pro 555X uses the Polaris 21 chip, a small 123 mm² die with 3,000 million transistors, yielding a density of 24.4M transistors per mm². The RX 580 employs the Polaris 20 chip, which is nearly twice the physical size at 232 mm² and packs 5,700 million transistors, resulting in a slightly higher density of 24.6M per mm². Both are fabricated by GlobalFoundries on a 14 nm process, so the density difference is marginal — the performance gap stems from sheer silicon area and resource allocation.

The execution resources differ dramatically. The Pro 555X has 768 shading units, 48 texture mapping units (TMUs), and 16 render output units (ROPs). The RX 580 triples the shading units to 2,304 and TMUs to 144, while doubling ROPs to 32. This translates into a raw throughput advantage for the RX 580: its pixel rate is 42.88 GPixel/s versus 14.51 GPixel/s for the Pro 555X, and its texture rate of 193.0 GTexel/s is over four times the Pro 555X’s 43.54 GTexel/s. FP32 compute follows the same pattern, with the RX 580 delivering 6.175 TFLOPS against 1,393.2 GFLOPS for the Pro 555X. Both GPUs run FP16 at the same rate as FP32 (1:1 ratio).

Memory architecture reinforces the divide. The Pro 555X pairs its 128-bit bus with 4 GB of GDDR5 running at 1470 MHz (5.9 Gbps effective), producing 94.08 GB/s. The RX 580 doubles the bus width to 256-bit, doubles capacity to 8 GB, and runs memory at 2000 MHz (8 Gbps effective), yielding 256.0 GB/s. The RX 580’s base clock of 1257 MHz and boost clock of 1340 MHz are not directly comparable to the Pro 555X, which lists no base or boost figures, only memory clocks. The mobile chip is also classified as an IGP with no power connectors, while the desktop card is dual-slot, 241 mm long, and requires a single 8-pin power connector plus a 450 W power supply recommendation.

Head-to-Head Benchmarks

The shared benchmark suite consists of three Geekbench tests, and the RX 580 wins all of them by overwhelming margins. In Geekbench Metal, the RX 580 scores 45235 against the Pro 555X’s 14479, a 68% difference. Geekbench OpenCL shows a similar story: 37453 for the RX 580 versus 12628 for the Pro 555X, a 66.3% gap. The largest relative margin appears in Geekbench Vulkan, where the RX 580’s 45173 dwarfs the Pro 555X’s 12855, representing a 71.5% lead. These deltas are consistent across APIs, suggesting the RX 580’s advantage is architectural rather than driver-specific — the extra shading units, TMUs, and memory bandwidth benefit all workloads equally.

The Pro 555X’s best showing is in OpenCL, where it narrows the gap to 66.3%, while its worst is in Vulkan at 71.5%. This pattern hints that the mobile chip’s limited memory bandwidth (94.08 GB/s) becomes a bottleneck in Vulkan workloads, which often stress memory throughput. The RX 580’s 256.0 GB/s bandwidth and 8 GB capacity provide headroom that the Pro 555X simply cannot match. Notably, the RX 580 also has a 3DMark Steel Nomad DX12 score of 1005, a test the Pro 555X does not have data for, but this only adds to the desktop card’s broader benchmark coverage. In terms of raw wins, the RX 580 takes 3 out of 3 shared tests, leaving the Pro 555X with zero head-to-head victories.

Specification Differences

The two GPUs differ in nearly every measurable specification beyond their shared GCN 4.0 architecture and 14 nm GlobalFoundries process. The chip itself changes from Polaris 21 to Polaris 20, with transistor count jumping from 3,000 million to 5,700 million and die size from 123 mm² to 232 mm². Transistor density is nearly identical at 24.4M vs 24.6M per mm², but the RX 580’s larger die accommodates far more resources.

Memory configuration is a major differentiator: 4 GB versus 8 GB of GDDR5, 128-bit versus 256-bit bus, and 94.08 GB/s versus 256.0 GB/s bandwidth. Memory clocks differ as well, with the Pro 555X at 1470 MHz (5.9 Gbps effective) and the RX 580 at 2000 MHz (8 Gbps effective). The RX 580 lists base and boost clocks (1257 MHz and 1340 MHz), while the Pro 555X only provides memory clocks. Shading units scale from 768 to 2,304, TMUs from 48 to 144, and ROPs from 16 to 32. Pixel rate, texture rate, and FP32 compute all increase by similar multiples.

Power and physical characteristics diverge sharply. The Pro 555X is an IGP with a 75 W TDP and no power connectors, while the RX 580 is a dual-slot card with a 185 W TDP, a single 8-pin connector, and a 450 W recommended power supply. The RX 580 measures 241 mm in length, while the Pro 555X has no listed dimensions. Bus interface also differs: PCIe 3.0 x8 for the mobile chip versus PCIe 3.0 x16 for the desktop card. Display outputs are portable-device dependent on the Pro 555X, whereas the RX 580 offers 1x HDMI 2.0b and 3x DisplayPort 1.4a. The RX 580 has a launch MSRP of 229 USD; the Pro 555X has no listed launch MSRP.

Where Each One Wins

The AMD Radeon RX 580 is the clear winner for any performance-focused task. Its 6.175 TFLOPS of FP32 compute, 256.0 GB/s of memory bandwidth, and 8 GB of VRAM make it suitable for demanding gaming, content creation, and GPU compute workloads. The Geekbench scores confirm this: it is 68% ahead in Metal, 66.3% ahead in OpenCL, and 71.5% ahead in Vulkan. The desktop card also offers a broader feature set with multiple display outputs, a full x16 bus interface, and a 450 W power supply recommendation for stable operation. Its 53rd percentile rank among all GPUs, while slightly below the Pro 555X’s 54th, still places it firmly in mid-range territory, competitive with rivals like the NVIDIA GeForce RTX 3050 Ti Mobile and GTX 1660 SUPER, which score within 0.4% of its average.

The AMD Radeon Pro 555X wins where power and space are at a premium. Its 75 W TDP, IGP form factor, and lack of power connectors make it a natural fit for thin-and-light laptops where the RX 580’s 185 W draw and dual-slot footprint would be impossible. The mobile chip’s average benchmark score of 13321 actually exceeds the RX 580’s 12928, and it sits within 0.4% of the NVIDIA GeForce GTX 480 and AMD FirePro M6100 in its nearest rival list. For professional mobile workloads that favor OpenCL and Metal — such as certain CAD or video editing applications — the Pro 555X provides a capable baseline without requiring dedicated cooling or power delivery. Its 14 nm GCN 4.0 architecture, while identical to the RX 580, is paired with a much smaller memory pool and narrower bus, so it will struggle with large datasets or high-resolution textures. The Pro 555X is best understood as a balanced mobile solution, while the RX 580 is a brute-force desktop performer.