AMD Radeon RX 6600 XT vs AMD Radeon RX 7800M Comparison

Head-to-Head Benchmarks

The recorded data presents a clear generational divide between these two AMD mobile graphics solutions. The AMD Radeon RX 7800M secures victory in 7 out of 10 head-to-head benchmark comparisons, with the AMD Radeon RX 6600 XT taking the remaining 3. The magnitude of these wins, however, tells a more nuanced story than the raw win count suggests.

The most decisive result comes from the Vulkan graphics test, where the RX 7800M scores 126,668 against the RX 6600 XT's 72,417, a 74.9% advantage. This is the single largest delta in the entire comparison and indicates that the newer architecture handles Vulkan workloads with substantially greater efficiency. The 3DMark Steel Nomad DX12 test shows a similarly commanding lead: the RX 7800M posts 2,994 points versus 1,804 for the RX 6600 XT, a 66% improvement. These two results alone establish the RX 7800M as the dominant performer in modern API-based workloads.

Compute performance follows the same trajectory. In Geekbench OpenCL, the RX 7800M achieves 120,778 compared to 80,503 for the RX 6600 XT, a 50% advantage. The Passmark GPU Compute test reinforces this with a 24.2% lead, as the RX 7800M scores 9,342 against 7,520. These numbers suggest that the RX 7800M's compute throughput scales well beyond what the older card can deliver, a finding consistent with its larger shader array and newer execution units.

DirectX 12 performance also favors the RX 7800M, though the margin narrows. The newer card scores 89 in Passmark DirectX 12 versus 61 for the RX 6600 XT, a 45.9% improvement. Passmark DirectX 11 shows a more modest 8% lead for the RX 7800M, with scores of 176 and 163 respectively. The overall Passmark G3D score, which aggregates multiple DirectX workloads, gives the RX 7800M a 7% edge, 17,613 versus 16,461. This smaller aggregate delta suggests that in some legacy scenarios, the older card remains competitive.

The RX 6600 XT's victories are concentrated in older or lighter workloads. In Passmark DirectX 9, it scores 194 against 174 for the RX 7800M, a 10.3% advantage. DirectX 10 shows a 9.2% lead, with scores of 109 and 99. The 2D graphics test also goes to the RX 6600 XT, though by a slim 2.2% margin, 912 versus 892. These wins indicate that the older architecture retains an edge in legacy API paths, likely due to its higher base clock and mature driver optimizations for these workloads.

The average benchmark score across all recorded tests places the RX 7800M at 27,883, compared to 24,442 for the RX 6600 XT, a difference of roughly 14%. The RX 7800M also sits at the 73rd percentile among all GPUs in the database, while the RX 6600 XT rests at the 70th percentile. When compared to its nearest rivals, the RX 7800M is essentially neck-and-neck with the AMD Radeon Pro Vega 20, trailing by just 0.2%, and sits 0.5% behind the NVIDIA GeForce GTX 980 Ti. The RX 6600 XT, by contrast, leads the NVIDIA GeForce GTX 1630 by 0.7% and trails the Intel Arc A350M by 0.8%.

FAQ

Q: Which GPU wins in modern DirectX 12 workloads?

A: The AMD Radeon RX 7800M is the clear winner in DirectX 12. It scores 89 points in Passmark DirectX 12 versus 61 for the RX 6600 XT, a 45.9% advantage. In the 3DMark Steel Nomad DX12 test, the RX 7800M posts 2,994 points against 1,804, a 66% lead.

Q: How do the two cards compare in compute performance?

A: The RX 7800M delivers substantially higher compute throughput. It scores 120,778 in Geekbench OpenCL versus 80,503 for the RX 6600 XT, a 50% advantage. Passmark GPU Compute shows a 24.2% lead, with scores of 9,342 and 7,520 respectively.

Q: Are there any workloads where the RX 6600 XT performs better?

A: Yes, the RX 6600 XT wins in three legacy or lighter tests. It leads in Passmark DirectX 9 with 194 versus 174, a 10.3% advantage. It also wins in DirectX 10 (109 versus 99, a 9.2% edge) and in the 2D graphics test (912 versus 892, a 2.2% lead).

Q: What is the overall performance gap between the two cards?

A: The average benchmark score for the RX 7800M is 27,883, while the RX 6600 XT averages 24,442. The RX 7800M also holds a higher percentile position at 73rd among all GPUs, compared to 70th for the RX 6600 XT.

Q: How does each card compare to its nearest competitors?

A: The RX 7800M sits within 0.8% of its nearest rivals, trailing the AMD Radeon Pro Vega 20 by 0.2% and the AMD FirePro S7150 by 0.8%. The RX 6600 XT leads the NVIDIA GeForce GTX 1630 by 0.7% and the NVIDIA GeForce GTX 780 Ti by 0.8%, but trails the Intel Arc A350M by 0.8% and the NVIDIA GeForce RTX 2080 SUPER by 1.1%.

Q: Which card has the higher boost clock?

A: The RX 6600 XT has a higher boost clock at 2,589 MHz, compared to 2,335 MHz for the RX 7800M. Despite this clock advantage for the older card, the RX 7800M still wins the majority of benchmark comparisons.

Architecture Differences

The architectural divide between these two GPUs spans two full RDNA generations. The AMD Radeon RX 7800M is built on RDNA 3.0 architecture, while the AMD Radeon RX 6600 XT uses RDNA 2.0. This generational shift brings fundamental changes in how each chip is designed and fabricated.

The manufacturing process marks the most significant underlying difference. The RX 7800M uses a 5 nm process node at TSMC, while the RX 6600 XT relies on a 7 nm node at the same foundry. This process shrink enables a dramatic increase in transistor density: the RX 7800M packs 81.2 million transistors per square millimeter, compared to 46.7 million for the RX 6600 XT. The RX 7800M's Navi 32 chip contains 28,100 million transistors on a 346 mm² die, whereas the RX 6600 XT's Navi 23 chip houses 11,060 million transistors on a 237 mm² die. The newer chip delivers more than double the transistor count on a die that is only about 46% larger.

Shader architecture differs considerably. The RX 7800M features 3,840 shading units, 240 texture mapping units, and 96 render output units. The RX 6600 XT offers 2,048 shading units, 128 TMUs, and 64 ROPs. Ray tracing hardware also scales: the RX 7800M includes 60 ray tracing cores, while the RX 6600 XT has 32. This doubling of core resources explains much of the performance gap in modern workloads.

Compute throughput reflects these architectural changes. The RX 7800M delivers 35.87 TFLOPS of FP32 performance, while the RX 6600 XT manages 10.60 TFLOPS. The FP16 calculation reveals a notable architectural difference: the RX 7800M achieves FP16 at a 1:1 ratio with FP32, also 35.87 TFLOPS, while the RX 6600 XT reaches 21.21 TFLOPS at a 2:1 ratio. This indicates the newer architecture has unified FP32 and FP16 execution paths, a design choice that simplifies shader scheduling.

The RX 7800M carries the codename "Wheat Nas" and belongs to the Navi Mobile (RX 7000M) generation. The RX 6600 XT belongs to the Navi II (RX 6000) generation. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, so API feature support is identical despite the architectural differences.

Specification Differences

The specification sheets for these two GPUs diverge across nearly every major category. Memory configuration leads the list: the RX 7800M offers 12 GB of GDDR6 memory on a 192-bit bus, delivering 432.0 GB/s of bandwidth. The RX 6600 XT provides 8 GB of GDDR6 on a 128-bit bus, with 256.0 GB/s of bandwidth. The RX 7800M therefore offers 50% more memory capacity and 68.75% more bandwidth.

Clock speeds tell a different story. The RX 6600 XT runs a base clock of 1,968 MHz and boosts to 2,589 MHz, with a game clock of 2,359 MHz. The RX 7800M operates at a lower 1,295 MHz base and 2,335 MHz boost, with a game clock of 2,145 MHz. The RX 6600 XT's higher clocks partially compensate for its smaller shader array, though not enough to overcome the RX 7800M's resource advantage.

Memory clocks also differ. The RX 7800M runs its memory at 2,250 MHz, translating to 18 Gbps effective. The RX 6600 XT operates at 2,000 MHz, or 16 Gbps effective. Power draw is comparable: the RX 7800M has a TDP of 180 W, while the RX 6600 XT is rated at 160 W.

Form factor and connectivity separate the two as well. The RX 7800M is an integrated graphics processor (IGP) with no power connectors, designed for portable devices with device-dependent display outputs. The RX 6600 XT is a dual-slot card measuring 190 mm in length, 110 mm in height, and 40 mm in width, requiring a single 8-pin power connector and a 450 W suggested power supply. The RX 7800M connects via PCIe 4.0 x16, while the RX 6600 XT uses PCIe 4.0 x8. The RX 6600 XT offers 1x HDMI 2.1 and 3x DisplayPort 1.4a outputs.

Production status and release timing also differ. The RX 7800M is listed as Active and was released on 2024-09-10, while the RX 6600 XT is End-of-life and launched on 2021-07-29. The RX 6600 XT had a launch MSRP of 379 USD. The RX 7800M's predecessor is noted as Polaris Mobile, while the RX 6600 XT's predecessor is Navi and its successor is Navi III.

Where Each One Wins

The AMD Radeon RX 7800M is the pick for modern, demanding workloads. Its 66% lead in 3DMark Steel Nomad DX12 and 74.9% advantage in Geekbench Vulkan make it the stronger choice for current-generation games and applications that leverage these APIs. The 50% lead in Geekbench OpenCL and 24.2% advantage in Passmark GPU Compute position it as the better option for compute-intensive tasks such as rendering, simulation, and machine learning inference. Its 12 GB memory capacity and 432.0 GB/s bandwidth provide more headroom for high-resolution textures and large datasets. The 45.9% DirectX 12 advantage ensures strong performance in most contemporary game titles.

The AMD Radeon RX 6600 XT retains relevance in specific scenarios. Its wins in Passmark DirectX 9 (10.3% ahead) and DirectX 10 (9.2% ahead) make it the better choice for older game libraries and legacy applications that rely on these APIs. The 2.2% edge in 2D graphics workloads suggests it handles desktop compositing and light 2D rendering tasks with slightly better efficiency. Its higher boost clock of 2,589 MHz may also provide an advantage in single-threaded or lightly threaded scenarios where clock speed matters more than raw core count.

For users running a mix of modern and legacy software, the RX 7800M offers the better overall package. Its 7 benchmark wins versus 3 for the RX 6600 XT, combined with a 14% average score advantage, make it the more versatile performer. The RX 6600 XT's strengths are confined to a narrow band of legacy workloads, while the RX 7800M dominates across the modern API landscape. The data indicates that the RX 7800M is the superior choice for anyone prioritizing current-generation performance, while the RX 6600 XT may still suffice for users with older software requirements and lower performance demands.