NVIDIA GeForce RTX 4080 vs NVIDIA GeForce RTX 4090 Mobile Comparison

The data tells an unusual story here: two GPUs built on the exact same silicon, yet separated by a clean sweep of benchmark wins for the desktop part. The NVIDIA GeForce RTX 4080 and the RTX 4090 Mobile share the AD103 chip, the same 5 nm TSMC process, and identical core counts, but the recorded results show the desktop card winning all nine head-to-head tests, several by wide margins. What follows is an investigation into where that gap comes from and what it means for anyone comparing the two.

Where Each One Wins

The short answer: the RTX 4080 wins everywhere, and the RTX 4090 Mobile wins nowhere in the recorded data. The head-to-head record stands at nine wins to zero. That said, the margin varies enormously by workload, and that variation is where the real insight lives.

The RTX 4090 Mobile looks most competitive in compute-adjacent and older API tests. In Geekbench OpenCL it scores 180,831 against 214,739, an 18.8 percent deficit, and in PassMark DirectX 10 it lands at 173 versus 204, 17.9 percent behind. Those are gaps a laptop buyer can live with, especially given the power envelope discussed below. In the PassMark G3D test, the broader graphics composite, the mobile part scores 27,212 against 34,457, a 26.6 percent deficit: meaningful but not a different class of hardware.

Where the mobile GPU genuinely struggles is modern graphics API throughput and raw compute. Geekbench Vulkan shows a 54.5 percent gap (170,774 vs 263,779), and PassMark GPU Compute shows the largest divide in the entire dataset at 67.4 percent (12,347 vs 20,671). The data implies that sustained compute workloads, the kind that push power draw over time, are where the mobile power budget bites hardest.

Against the full database, both GPUs sit high in the rankings: the RTX 4080 at the 86th percentile and the RTX 4090 Mobile at the 84th. Interesting, then, that despite losing every direct test, the mobile part ranks only two percentile points lower overall. The two are near-neighbors in the global distribution even though the desktop card dominates their direct matchups.

Architecture Differences

Here is the curiosity at the heart of this comparison: architecturally, these are the same GPU. Both use the AD103 chip, Ada Lovelace architecture, TSMC's 5 nm process, 45,900 million transistors on a 379 mm² die, and a transistor density of 121.1M per mm². Core counts are identical across the board: 9,728 shading units, 304 TMUs, 112 ROPs, 76 RT cores, and 304 tensor cores. The bus interface is PCIe 4.0 x16 on both, and both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

The differences are almost entirely about clocks, memory type, and power. The desktop RTX 4080 runs a 2205 MHz base and 2505 MHz boost, while the mobile part runs 1335 MHz base and 1695 MHz boost. That clock gap explains most of the performance delta on its own: peak FP32 throughput is 48.74 TFLOPS on the desktop card versus 32.98 TFLOPS on the mobile, and FP16 matches FP32 at a 1:1 ratio on both.

Memory diverges in type and speed, though not in size or bus width. Both carry 16 GB on a 256-bit bus, but the desktop uses GDDR6X at 22.4 Gbps effective for 716.8 GB/s of bandwidth, while the mobile uses GDDR6 at 18 Gbps effective for 576.0 GB/s. The throughput figures follow the clocks: 280.6 GPixel/s and 761.5 GTexel/s for the desktop versus 189.8 GPixel/s and 515.3 GTexel/s for the mobile.

The power and form factor story is the sharpest contrast of all. The desktop card has a 320 W TDP, a triple-slot footprint, one 16-pin power connector, and a suggested 700 W PSU, with physical dimensions of 310 mm length, 140 mm height, and 61 mm width. The mobile GPU has a 120 W TDP, no power connectors, and an IGP-style integrated form factor with portable-device-dependent display outputs and no fixed dimensions. Both are GeForce 40-series parts; the desktop launched in September 2022 and the mobile in January 2023. The desktop card is now end-of-life, while the mobile remains active. Only the desktop has a recorded launch MSRP: 1,199 USD.

Head-to-Head Benchmarks

Walking through the recorded matchups, the desktop RTX 4080's wins cluster into three tiers.

Closest contests, under 20 percent: Geekbench OpenCL at 18.8 percent (214,739 vs 180,831), PassMark DirectX 10 at 17.9 percent (204 vs 173), PassMark DirectX 9 at 19.4 percent (370 vs 310), and PassMark DirectX 11 at 19.8 percent (314 vs 262). In legacy DirectX tests the mobile part holds up respectably, which makes sense: older APIs are less demanding of bandwidth and sustained clocks.

Middle tier, 20 to 30 percent: PassMark DirectX 12 at 23.4 percent (132 vs 107), PassMark G2D at 25.9 percent (1239 vs 984), and the PassMark G3D composite at 26.6 percent (34,457 vs 27,212). The DirectX 12 result is worth pausing on: the gap widens as the API gets more modern, and the Vulkan result confirms the pattern dramatically.

Widest gaps: Geekbench Vulkan at 54.5 percent (263,779 vs 170,774) and PassMark GPU Compute at 67.4 percent (20,671 vs 12,347). The Vulkan discrepancy is larger than any clock or bandwidth difference alone would suggest, and the compute result is more than double in the desktop card's favor. The data raises a question worth flagging: why does Vulkan lag so much farther behind than OpenCL on the mobile part, when both measure general GPU throughput? Whatever the cause, sustained workloads clearly favor the part with the 320 W envelope.

For context, average benchmark scores are 54,247 for the desktop and 43,667 for the mobile. The desktop's nearest rival by average score is the RTX 4080 SUPER at essentially a dead heat (0.1 percent), with the Radeon Pro W5700X at -1.1 percent, the RX 6750 GRE 12 GB at -2.6 percent, and the Radeon 8060S at -2.7 percent. The mobile part's rivals are the Quadro M6000 (0.8 percent), RTX 5050 Mobile (0.9 percent), Quadro M6000 24 GB (0.9 percent), and RTX A6000 (-0.9 percent).

FAQ

Q: Do the RTX 4080 and RTX 4090 Mobile use the same chip?

A: Yes. Both are built on the AD103 die, Ada Lovelace architecture, TSMC 5 nm process, with 45,900 million transistors, a 379 mm² die, and identical counts of 9,728 shading units, 304 TMUs, 112 ROPs, 76 RT cores, and 304 tensor cores.

Q: How much faster is the RTX 4080 in games?

A: In the PassMark G3D test the desktop card scores 34,457 versus 27,212, a 26.6 percent lead. In individual DirectX tests the lead ranges from 17.9 percent (DirectX 10) to 23.4 percent (DirectX 12).

Q: Where is the gap biggest?

A: PassMark GPU Compute, where the desktop scores 20,671 against 12,347, a 67.4 percent difference. Geekbench Vulkan is second at 54.5 percent.

Q: How much power does each consume?

A: The desktop RTX 4080 has a 320 W TDP with a suggested 700 W PSU, while the RTX 4090 Mobile runs at a 120 W TDP with no power connectors.

Q: What memory does each have?

A: Both have 16 GB on a 256-bit bus. The desktop uses GDDR6X at 22.4 Gbps effective (716.8 GB/s), and the mobile uses GDDR6 at 18 Gbps effective (576.0 GB/s).

Q: Are both still in production?

A: No. The desktop RTX 4080 is end-of-life, while the RTX 4090 Mobile remains active. The desktop launched September 2022, the mobile January 2023.

Specification Differences

• Clocks: 2205 MHz base / 2505 MHz boost (desktop) vs 1335 MHz base / 1695 MHz boost (mobile)
• Memory type and speed: GDDR6X at 22.4 Gbps effective, 716.8 GB/s vs GDDR6 at 18 Gbps effective, 576.0 GB/s (both 16 GB, 256-bit)
• FP32/FP16 throughput: 48.74 TFLOPS vs 32.98 TFLOPS (both 1:1 FP16)
• Pixel and texture rates: 280.6 GPixel/s and 761.5 GTexel/s vs 189.8 GPixel/s and 515.3 GTexel/s
• TDP: 320 W vs 120 W
• Form factor: triple-slot card (310 x 140 x 61 mm) vs IGP-style integrated mobile part
• Power delivery: one 16-pin connector, 700 W suggested PSU vs no connectors
• Display outputs: 1x HDMI 2.1 and 3x DisplayPort 1.4a vs portable-device-dependent
• Status and dates: end-of-life, September 2022 vs active, January 2023
• Launch MSRP: 1,199 USD recorded for the desktop; none recorded for the mobile
• Generation labels: GeForce 40 vs GeForce 40 Mobile

Everything else, the chip, node, transistor count, die size, core counts, bus, and API support, is identical.

The Verdict

The recorded data leaves no ambiguity about performance: the desktop RTX 4080 wins every one of the nine head-to-head benchmarks, from a 17.9 percent edge in legacy DirectX 10 to a 67.4 percent rout in GPU compute. Anyone choosing purely on results, particularly for sustained compute or modern Vulkan workloads, should pick the desktop card, accepting its 320 W TDP, triple-slot footprint, and 700 W PSU requirement.

The RTX 4090 Mobile's case rests on what the numbers imply rather than raw scores. It delivers the same silicon, the same 16 GB of VRAM, and the same feature set at a 120 W TDP in an integrated mobile form, while staying within two percentile points of the desktop card against the full database (84th vs 86th). In older API tests it stays under 20 percent behind. For a portable system where the desktop card's power and physical envelope are simply not options, the mobile part is the only one of the two that exists as a choice at all, and its active production status against the desktop's end-of-life listing reinforces that. The desktop card is the performance pick; the mobile part is the portability pick, and the data quantifies exactly what that trade costs.