AMD Steam Machine GPU vs NVIDIA B300 SXM6 AC Comparison

# FAQ

Q: What are the two products compared here?

A: The AMD Steam Machine GPU is a console-oriented graphics processor built on the RDNA 3.0 architecture with the Navi 33 chip, while the NVIDIA B300 SXM6 AC is a server-grade accelerator from the Blackwell Ultra generation using the GB110 chip.

Q: How do the memory capacities compare?

A: The AMD Steam Machine GPU carries 8 GB of GDDR6 memory on a 128-bit bus with 288.0 GB/s bandwidth. The NVIDIA B300 SXM6 AC features 288 GB of HBM3e memory on a 8192-bit bus, delivering 8.19 TB/s bandwidth. That is a 36-fold increase in capacity and roughly 28 times the bandwidth.

Q: Which chip has the larger transistor count?

A: The NVIDIA B300 SXM6 AC has 208,000 million transistors on a 1628 mm² die, while the AMD Steam Machine GPU has 13,300 million transistors on a 204 mm² die. The NVIDIA part packs more than 15 times the transistor count and uses a 5 nm process versus AMD's 6 nm node.

Q: What is the performance percentile ranking for each?

A: The AMD Steam Machine GPU sits at the 50th percentile among all GPUs in the database with an average benchmark score of zero, meaning no recorded benchmarks are available. The NVIDIA B300 SXM6 AC ranks at the 100th percentile with an average benchmark score of 369831 in Geekbench OpenCL.

Q: What are the power requirements?

A: The AMD Steam Machine GPU has a TDP of 110 W and requires no power connectors. The NVIDIA B300 SXM6 AC has a TDP of 1100 W, needs a 1500 W suggested PSU, and uses an SXM module slot format.

Q: Which API support differs between the two?

A: The AMD Steam Machine GPU supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The NVIDIA B300 SXM6 AC lists N/A for DirectX, OpenGL, and Vulkan, reflecting its server-oriented role with no display outputs.

# Architecture Differences

The architectural gap between these two chips is fundamental. The AMD Steam Machine GPU belongs to the RDNA 3.0 family, a graphics-first design aimed at gaming workloads. Its Navi 33 chip uses a 6 nm TSMC process and packs 13,300 million transistors into a 204 mm² die, resulting in a transistor density of 65.2M per mm². The NVIDIA B300 SXM6 AC belongs to the Blackwell Ultra generation, a server-focused architecture engineered for compute density. Its GB110 chip uses a 5 nm TSMC process, integrates 208,000 million transistors on a 1628 mm² die, and reaches a density of 127.8M per mm².

The compute feature sets diverge sharply. The AMD part includes 28 RT cores dedicated to hardware ray tracing, alongside 1792 shading units, 112 texture mapping units, and 64 render output units. The NVIDIA part does not list RT cores but includes 592 tensor cores, which are specialized for AI and deep learning operations. This is not a minor difference: the presence of tensor cores on the NVIDIA side and RT cores on the AMD side points to entirely different optimization targets.

Clock speeds also differ in character. The AMD Steam Machine GPU operates at a base of 1720 MHz, a game clock of 2250 MHz, and a boost of 2450 MHz. The NVIDIA B300 SXM6 AC has a lower base of 1665 MHz and a boost of 2032 MHz, but it is not clocked for gaming workloads. The memory clocks reflect this too: AMD's memory runs at 2250 MHz with 18 Gbps effective, while NVIDIA's memory runs at 2000 MHz with 8 Gbps effective, yet the latter's 8192-bit bus overwhelms the former's 128-bit bus in total bandwidth.

The power envelope separates them completely. The AMD Steam Machine GPU draws 110 W with no external power connectors, a design suited for compact console form factors. The NVIDIA B300 SXM6 AC draws 1100 W, requires a 1500 W suggested PSU, and mounts as an SXM module. The physical dimensions also differ: AMD lists a length of 156 mm, height of 152 mm, and width of 162 mm, while NVIDIA provides no dimension data for the SXM module.

Production status for both is listed as Active. The release dates are close: NVIDIA's B300 SXM6 AC launched on 2025-09-10, while AMD's Steam Machine GPU followed on 2026-06-28. The NVIDIA part has a predecessor, Server Hopper, and a successor, Server Rubin, while the AMD part lists none.

# The Verdict

The data points to a clear split by use case. The NVIDIA B300 SXM6 AC is a compute monster, ranking at the 100th percentile among all GPUs with a Geekbench OpenCL score of 369831. That score puts it 7% ahead of the NVIDIA B200, 10.4% ahead of the NVIDIA H200 NVL, 16.3% ahead of the AMD Instinct MI300X, and 25% ahead of the NVIDIA L40S. Its 288 GB of HBM3e memory, 8.19 TB/s bandwidth, and 76.99 TFLOPS of FP32 performance make it suited for server workloads where memory capacity and raw throughput dominate.

The AMD Steam Machine GPU has no recorded benchmarks and a percentile ranking of 50, meaning it sits exactly in the middle of the database's GPU distribution. Its 17.56 TFLOPS of FP32 performance, 8 GB GDDR6 memory, and 288.0 GB/s bandwidth are modest figures by comparison. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, and includes display outputs (1x HDMI 2.1a, 1x DisplayPort 2.1), making it a functional graphics card for gaming. The NVIDIA part has no display outputs and no consumer API support.

The choice is not about which is "better" in absolute terms. It is about matching hardware to workload. The NVIDIA B300 SXM6 AC delivers compute performance that places it at the top of the database, but it cannot output video and does not support gaming APIs. The AMD Steam Machine GPU is a low-power (110 W), console-oriented part with display outputs and full graphics API support, but it lacks the memory capacity, bandwidth, and compute throughput of the server chip. The recorded data shows two products designed for different ecosystems: one for rendering and gaming, the other for accelerated computing at scale.

# Specification Differences

The two products differ in nearly every measurable specification. The process node is 6 nm for AMD versus 5 nm for NVIDIA. Transistor count is 13,300 million versus 208,000 million. Die size is 204 mm² versus 1628 mm². Transistor density is 65.2M per mm² versus 127.8M per mm².

Clock speeds: AMD base 1720 MHz, boost 2450 MHz, game 2250 MHz, memory 2250 MHz (18 Gbps effective). NVIDIA base 1665 MHz, boost 2032 MHz, no game clock, memory 2000 MHz (8 Gbps effective).

Memory: AMD has 8 GB GDDR6 on a 128-bit bus with 288.0 GB/s bandwidth. NVIDIA has 288 GB HBM3e on an 8192-bit bus with 8.19 TB/s bandwidth.

Compute units: AMD has 1792 shading units, 112 TMUs, 64 ROPs, and 28 RT cores. NVIDIA has 18944 shading units, 592 TMUs, 24 ROPs, and 592 tensor cores. AMD lists no tensor cores; NVIDIA lists no RT cores.

Rates and throughput: AMD pixel rate is 156.8 GPixel/s, texture rate is 274.4 GTexel/s, FP32 is 17.56 TFLOPS, FP16 is 17.56 TFLOPS (1:1). NVIDIA pixel rate is 48.77 GPixel/s, texture rate is 1,202.9 GTexel/s, FP32 is 76.99 TFLOPS, FP16 is 76.99 TFLOPS (1:1). NVIDIA's texture rate is over four times higher, but its pixel rate is lower due to fewer ROPs (24 versus 64).

Power and physical: AMD TDP is 110 W with no power connectors. NVIDIA TDP is 1100 W with a 1500 W suggested PSU. AMD uses a standard card with dimensions 156 mm by 152 mm by 162 mm. NVIDIA uses an SXM module with no listed dimensions.

Interfaces and outputs: AMD has 1x HDMI 2.1a and 1x DisplayPort 2.1. NVIDIA has no outputs. AMD's bus interface is not listed; NVIDIA uses PCIe 6.0 x16. API support: AMD lists DirectX 12 Ultimate (12_2), OpenGL 4.6, Vulkan 1.4. NVIDIA lists N/A for all three.

Release timing: NVIDIA launched 2025-09-10; AMD launched 2026-06-28. NVIDIA has a predecessor (Server Hopper) and successor (Server Rubin); AMD has neither.

# Head-to-Head Benchmarks

The head-to-head benchmark table is empty, and the win counts are zero for both sides. However, the database does contain a recorded Geekbench OpenCL score for the NVIDIA B300 SXM6 AC: 369831. That single measurement places it at the 100th percentile among all GPUs. The AMD Steam Machine GPU has no benchmark entries in the database, with an average benchmark score of zero and a 50th percentile ranking.

The absence of AMD benchmark data prevents a direct comparison on the same test. What the recorded data does show is the NVIDIA part's position relative to its nearest rivals in the database. The B300 SXM6 AC leads the NVIDIA B200 by 7%, the NVIDIA H200 NVL by 10.4%, the AMD Instinct MI300X by 16.3%, and the NVIDIA L40S by 25%. These deltas are meaningful for server procurement decisions: the B300 SXM6 AC is the fastest among comparable accelerators in the database.

For the AMD Steam Machine GPU, the only quantitative anchor is its FP32 rating of 17.56 TFLOPS, which is about 23% of the NVIDIA part's 76.99 TFLOPS. Its memory bandwidth of 288.0 GB/s is roughly 3.5% of NVIDIA's 8.19 TB/s. Its texture rate of 274.4 GTexel/s is about 23% of NVIDIA's 1,202.9 GTexel/s. Its pixel rate of 156.8 GPixel/s, however, is over three times NVIDIA's 48.77 GPixel/s, reflecting the AMD part's rasterization focus.

The wins, as recorded, are one-sided: the NVIDIA B300 SXM6 AC has a benchmark score and a top percentile rank, while the AMD Steam Machine GPU has neither. The data cannot support a claim that the AMD part competes with the NVIDIA part in compute workloads. It can support a claim that the AMD part is a different class of device, one defined by low power consumption (110 W), console form factor, and display output support.

# Where Each One Wins

The NVIDIA B300 SXM6 AC wins in every compute-oriented category recorded in the database. Its Geekbench OpenCL score of 369831 is the highest among its nearest rivals, with deltas of 7% over the B200, 10.4% over the H200 NVL, 16.3% over the MI300X, and 25% over the L40S. Its FP32 throughput of 76.99 TFLOPS, FP16 throughput of 76.99 TFLOPS, texture rate of 1,202.9 GTexel/s, and memory bandwidth of 8.19 TB/s place it in a performance tier that the AMD part cannot approach. Its 288 GB memory capacity is suited for large model inference and training datasets. Its 592 tensor cores indicate a specialization for AI workloads. The absence of display outputs and consumer API support confirms that this is a compute accelerator, not a graphics card.

The AMD Steam Machine GPU wins in the categories that matter for a console or gaming PC. Its TDP of 110 W is one-tenth of NVIDIA's 1100 W, enabling a compact, fan-less or low-noise design with no power connectors. Its pixel rate of 156.8 GPixel/s is over three times NVIDIA's 48.77 GPixel/s, which is relevant for rasterization-heavy game rendering. Its support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, combined with HDMI 2.1a and DisplayPort 2.1 outputs, makes it a functional consumer graphics solution. Its 8 GB GDDR6 memory, while small by server standards, is adequate for the console class. Its 28 RT cores provide hardware ray tracing support, a feature absent from the NVIDIA part's specifications.

The use-case split is clean. For AI training, scientific computing, or any workload that demands massive memory bandwidth and tensor core throughput, the NVIDIA B300 SXM6 AC is the only choice supported by the data. For gaming, media playback, or any task requiring display output and graphics API compatibility, the AMD Steam Machine GPU is the functional option. The two products do not overlap in their strengths. The database records one benchmark for the NVIDIA part and none for the AMD part, which itself is a statement about where each product is expected to operate.