NVIDIA GeForce RTX 4090 Max-Q vs NVIDIA Rubin GPU Comparison

Where Each One Wins

The recorded data draws a sharp dividing line between these two NVIDIA parts. The GeForce RTX 4090 Max-Q is a mobile graphics processor built for portable devices, while the Rubin GPU is a server-class accelerator designed for data center workloads. Neither part has recorded benchmark scores in the database, so the win split here is based on architectural capabilities rather than measured performance deltas.

The RTX 4090 Max-Q shows its advantage in areas tied to client-side rendering and display output. It carries 16 GB of GDDR6 memory on a 256-bit bus, delivers 576.0 GB/s of bandwidth, and supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. Its display outputs are listed as portable device dependent, which means it can drive screens on laptops or all-in-one systems. The Rubin GPU, by contrast, lists no display outputs at all. That single difference defines the use-case split: the 4090 Max-Q wins for graphics output, the Rubin wins for raw compute throughput.

The Rubin GPU dominates in sheer processing resources. It packs 28,672 shading units, 896 texture mapping units, and 896 tensor cores. Its FP32 throughput is 130.0 TFLOPS, and its FP16 throughput reaches 260.0 TFLOPS with a 2:1 ratio. The 4090 Max-Q counters with 9,728 shading units, 304 TMUs, and 304 tensor cores, producing 28.31 TFLOPS for both FP32 and FP16 at a 1:1 ratio. The Rubin GPU holds a 4.59x advantage in FP32 throughput and a 9.18x advantage in FP16 throughput. The 4090 Max-Q does not match these figures anywhere.

Memory capacity and bandwidth also split decisively. The Rubin GPU carries 288 GB of HBM4 memory across a 16,384-bit bus, yielding 22.1 TB/s of bandwidth. The 4090 Max-Q has 16 GB of GDDR6 on a 256-bit bus, yielding 576.0 GB/s. The Rubin GPU offers 18x the memory capacity and roughly 38x the bandwidth. The 4090 Max-Q retains a pixel rate advantage, however, at 163.0 GPixel/s versus the Rubin's 54.41 GPixel/s, which aligns with the mobile part's role in rasterized graphics output.

The Verdict

The data directs each part to a distinct audience. The GeForce RTX 4090 Max-Q belongs in portable systems where graphics output, display connectivity, and standard graphics APIs are required. It uses the Ada Lovelace architecture on a 5 nm TSMC node, draws 80 W, fits an IGP slot width, and needs no power connectors. Its production status is active, and it released on 2023-01-02. Its predecessor is the GeForce 30 Mobile series and its successor is the GeForce 50 Mobile series, which places it firmly in the laptop GPU lineage.

The NVIDIA Rubin GPU serves server environments. It uses the Rubin architecture on a 3 nm TSMC node, draws 2,300 W, requires a 2,700 W suggested PSU, and mounts as an SXM Module. It has no display outputs and no DirectX, OpenGL, or Vulkan support. Its production status is active, with a release date of 2025-12-31. Its predecessor is Server Blackwell. The 4090 Max-Q cannot match the Rubin's FP32, FP16, memory capacity, or bandwidth, and the Rubin cannot match the 4090 Max-Q's pixel rate or graphics API compatibility.

For a user seeking a laptop or portable workstation GPU, the 4090 Max-Q is the only viable option between the two. For a data center operator seeking maximum compute throughput in a server chassis, the Rubin GPU is the only viable option. Neither part competes in the other's domain.

Head-to-Head Benchmarks

The database contains no recorded head-to-head benchmark scores for these two parts, and both have an average benchmark score of 0 with a percentile rank of 50 against all GPUs. The comparison therefore relies on the specification fields.

The largest win for the Rubin GPU appears in FP32 throughput. The Rubin delivers 130.0 TFLOPS against the 4090 Max-Q's 28.31 TFLOPS, a 4.59x gap. In FP16, the Rubin delivers 260.0 TFLOPS against the 4090 Max-Q's 28.31 TFLOPS, a 9.18x gap. Texture rate follows the same pattern: the Rubin reaches 2,031.2 GTexel/s, while the 4090 Max-Q reaches 442.3 GTexel/s, a 4.59x gap. Memory bandwidth shows the most extreme difference: 22.1 TB/s versus 576.0 GB/s, roughly a 38x gap.

The 4090 Max-Q wins in pixel rate. It delivers 163.0 GPixel/s, while the Rubin GPU delivers 54.41 GPixel/s, a 3x advantage for the mobile part. The 4090 Max-Q also has a higher base clock at 930 MHz versus the Rubin's 700 MHz, though the Rubin's boost clock of 2,267 MHz exceeds the 4090 Max-Q's 1,455 MHz. The 4090 Max-Q supports graphics APIs: DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the Rubin lists N/A for all three. The 4090 Max-Q uses a PCIe 4.0 x16 interface, while the Rubin uses PCIe 6.0 x16.

FAQ

Q: Which GPU has more shading units?

A: The NVIDIA Rubin GPU has 28,672 shading units, while the GeForce RTX 4090 Max-Q has 9,728 shading units.

Q: What is the memory capacity difference?

A: The Rubin GPU has 288 GB of HBM4 memory, while the RTX 4090 Max-Q has 16 GB of GDDR6 memory.

Q: Does the Rubin GPU support DirectX?

A: No. The Rubin GPU lists DirectX as N/A, along with OpenGL and Vulkan as N/A. The RTX 4090 Max-Q supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: Which part has a higher pixel rate?

A: The RTX 4090 Max-Q has a pixel rate of 163.0 GPixel/s, which is higher than the Rubin GPU's 54.41 GPixel/s.

Q: What are the power requirements?

A: The RTX 4090 Max-Q has a TDP of 80 W and needs no power connectors. The Rubin GPU has a TDP of 2,300 W and a suggested PSU of 2,700 W.

Q: Which GPU has a higher boost clock?

A: The Rubin GPU has a boost clock of 2,267 MHz, which is higher than the RTX 4090 Max-Q's boost clock of 1,455 MHz. The 4090 Max-Q has a higher base clock at 930 MHz versus 700 MHz.

Architecture Differences

The two parts use different architectures. The RTX 4090 Max-Q uses Ada Lovelace with the AD103 chip, while the Rubin GPU uses the Rubin architecture with the GR100 chip. The process nodes differ: the 4090 Max-Q is fabricated on a 5 nm TSMC node, and the Rubin GPU uses a 3 nm TSMC node. Transistor counts reflect the scale difference: the 4090 Max-Q has 45,900 million transistors on a 379 mm² die, while the Rubin GPU has 336,000 million transistors on a 1,456 mm² die. Transistor density is 121.1M per mm² for the 4090 Max-Q and 230.8M per mm² for the Rubin GPU.

Ray tracing cores are present only in the 4090 Max-Q, which has 76 RT cores. The Rubin GPU lists no RT core count. Tensor cores exist in both: 304 in the 4090 Max-Q and 896 in the Rubin GPU. The 4090 Max-Q uses a 1:1 FP16 to FP32 ratio, while the Rubin GPU uses a 2:1 ratio, meaning the Rubin's FP16 throughput is double its FP32 throughput.

The 4090 Max-Q is part of the GeForce 40-series and the GeForce 40 Mobile generation. The Rubin GPU belongs to the Server Rubin (Rxx) generation. The 4090 Max-Q's predecessor is GeForce 30 Mobile and its successor is GeForce 50 Mobile. The Rubin GPU's predecessor is Server Blackwell, with no successor listed. The 4090 Max-Q is a mobile IGP with no power connectors, while the Rubin GPU is an SXM Module with a suggested PSU of 2,700 W.

Specification Differences

The recorded specification fields show several direct differences.

• Process node: 5 nm (4090 Max-Q) versus 3 nm (Rubin)
• Transistors: 45,900 million versus 336,000 million
• Die size: 379 mm² versus 1,456 mm²
• Base clock: 930 MHz versus 700 MHz
• Boost clock: 1,455 MHz versus 2,267 MHz
• Memory size: 16 GB GDDR6 versus 288 GB HBM4
• Memory bus width: 256 bit versus 16,384 bit
• Memory bandwidth: 576.0 GB/s versus 22.1 TB/s
• Shading units: 9,728 versus 28,672
• TMUs: 304 versus 896
• ROPs: 112 versus 24
• RT cores: 76 versus none listed
• Tensor cores: 304 versus 896
• Pixel rate: 163.0 GPixel/s versus 54.41 GPixel/s
• Texture rate: 442.3 GTexel/s versus 2,031.2 GTexel/s
• FP32: 28.31 TFLOPS versus 130.0 TFLOPS
• FP16: 28.31 TFLOPS versus 260.0 TFLOPS
• TDP: 80 W versus 2,300 W
• Slot width: IGP versus SXM Module
• Power connectors: None versus not listed
• Bus interface: PCIe 4.0 x16 versus PCIe 6.0 x16
• Display outputs: Portable device dependent versus no outputs
• DirectX: 12 Ultimate (12_2) versus N/A
• OpenGL: 4.6 versus N/A
• Vulkan: 1.4 versus N/A
• Release date: 2023-01-02 versus 2025-12-31

The 4090 Max-Q is the only one with display output capability and graphics API support. The Rubin GPU is the only one with a PCIe 6.0 interface and a suggested PSU. Both parts show an active production status and a 50th percentile rank against all GPUs, with no recorded benchmark scores.