AMD Radeon 660M vs AMD Radeon HD 7770M Comparison

Head-to-Head Benchmarks

The benchmark data presents a unique situation for this comparison: there is no direct head-to-head benchmark suite shared between the two GPUs. The AMD Radeon 660M has results in Geekbench OpenCL and Geekbench Vulkan, while the AMD Radeon HD 7770M has a single result in Geekbench Metal. This means the comparison must be built from their respective average benchmark scores and percentile rankings rather than identical test runs.

The AMD Radeon 660M posts an average benchmark score of 13,812 across its two tests. Its Geekbench OpenCL score is 12,876, and its Geekbench Vulkan score is 14,748. The AMD Radeon HD 7770M, by contrast, has an average benchmark score of 13,536, derived entirely from its Geekbench Metal result of 13,536. The delta between the two averages is 276 points, which works out to roughly 2% in favor of the 660M. This is a narrow margin, and one that sits within the noise of typical synthetic benchmark variance.

Looking at percentile placement, the 660M lands in the 55th percentile of all GPUs, while the HD 7770M sits just one point lower at the 54th percentile. That single percentile point underscores how close these two parts are in overall standing. The 660M’s nearest rivals include the NVIDIA RTX A2000 Mobile at 13,821 (-0.1% delta), the AMD Radeon RX 570X at 13,871 (-0.4%), the AMD Radeon RX 7900 XT at 13,745 (+0.5%), and the NVIDIA Tesla K10 at 14,029 (-1.5%). The HD 7770M’s nearest rivals include the AMD Radeon RX 9070 XT at 13,543 (-0.1%), the NVIDIA GeForce GTX 570 at 13,515 (+0.2%), the NVIDIA P106-090 at 13,470 (+0.5%), and the AMD Radeon Pro 555 at 13,407 (+1%).

The data shows that both GPUs cluster around the same performance tier. The 660M is 0.5% ahead of the RX 7900 XT in average score, while the HD 7770M is 0.2% ahead of the GTX 570. Neither part is dramatically faster than the other; the difference is more about which synthetic workload is being run. The 660M’s Vulkan score of 14,748 is notably higher than its OpenCL score of 12,876, suggesting that the newer RDNA 2.0 architecture handles Vulkan workloads particularly well. The HD 7770M’s Metal result of 13,536 sits between those two numbers, indicating that on Apple’s API it performs competitively with the 660M’s OpenCL showing but falls short of its Vulkan peak.

For raw throughput, the 660M delivers 1,459.2 GFLOPS of FP32 compute, while the HD 7770M delivers 691.2 GFLOPS. That is a 2.11x advantage for the 660M in theoretical floating-point performance. However, the HD 7770M has more shading units (512 vs. 384) and more texture mapping units (32 vs. 24), which means its per-unit efficiency is lower but its parallel resource count is higher. Pixel rate favors the 660M at 30.40 GPixel/s versus 10.80 GPixel/s, and texture rate also favors the 660M at 45.60 GTexel/s versus 21.60 GTexel/s.

Architecture Differences

The architectural gap between these two GPUs is generational. The AMD Radeon 660M is built on RDNA 2.0 architecture, part of the Navi II IGP generation from Rembrandt Mobile, fabricated on a 6 nm process at TSMC. The AMD Radeon HD 7770M uses GCN 1.0 architecture, part of the London generation from the HD 7700M series, fabricated on a 28 nm process, also at TSMC. The process node difference is substantial: 6 nm versus 28 nm, which explains the transistor density disparity. The 660M packs 13,100 million transistors on a 208 mm² die, yielding a density of 63.0 million transistors per mm². The HD 7770M has 1,500 million transistors on a 123 mm² die, yielding just 12.2 million transistors per mm².

The 660M includes 6 ray tracing cores, a feature entirely absent from the HD 7770M, which has no RT cores listed. The 660M also supports DirectX 12 Ultimate (12_2), while the HD 7770M is limited to DirectX 12 (11_1). Vulkan support differs as well: the 660M supports Vulkan 1.4, whereas the HD 7770M supports Vulkan 1.2.170. OpenGL support is identical at 4.6 for both.

Memory architecture is another fundamental split. The 660M uses system-shared memory with a system-dependent bandwidth figure, meaning its performance scales with the host system’s RAM configuration. The HD 7770M has dedicated 1024 MB of GDDR5 memory on a 128-bit bus, delivering a fixed 64.00 GB/s of bandwidth. The 660M’s memory clock is listed as system shared, while the HD 7770M’s memory runs at 1000 MHz with 4 Gbps effective transfer rate.

The bus interface differs: the 660M uses PCIe 4.0 x8, while the HD 7770M uses PCIe 2.0 x16. Power draw is close but favors the older part: the 660M is rated at 40 W TDP, while the HD 7770M is rated at 32 W TDP. The 660M is an integrated graphics processor (IGP) with no slot width and no power connectors, while the HD 7770M has no slot width or power connector data listed. Both are end-of-life products, with the 660M released in 2022 and the HD 7770M released in 2012.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon 660M has an average benchmark score of 13,812, which is 276 points higher than the AMD Radeon HD 7770M’s average of 13,536. This represents roughly a 2% advantage for the 660M.

Q: Does the AMD Radeon HD 7770M have more shading units?

A: Yes. The HD 7770M has 512 shading units, while the 660M has 384. Despite having fewer units, the 660M achieves higher FP32 throughput at 1,459.2 GFLOPS versus 691.2 GFLOPS for the HD 7770M.

Q: What is the memory configuration difference?

A: The 660M uses system-shared memory with system-dependent bandwidth, while the HD 7770M has 1024 MB of dedicated GDDR5 memory on a 128-bit bus with a fixed 64.00 GB/s bandwidth.

Q: Which GPU supports ray tracing?

A: Only the AMD Radeon 660M supports ray tracing, with 6 dedicated ray tracing cores. The AMD Radeon HD 7770M has no ray tracing cores listed in its specifications.

Q: How do the process nodes compare?

A: The 660M is fabricated on a 6 nm process at TSMC, while the HD 7770M uses a 28 nm process at the same foundry. The 660M’s die is 208 mm² with 13,100 million transistors, whereas the HD 7770M’s die is 123 mm² with 1,500 million transistors.

Q: Which GPU has better API support?

A: The 660M supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the HD 7770M supports DirectX 12 (11_1) and Vulkan 1.2.170. Both support OpenGL 4.6.

Specification Differences

The two GPUs differ across nearly every measured specification. The 660M uses RDNA 2.0 architecture with a 6 nm process, while the HD 7770M uses GCN 1.0 with a 28 nm process. Transistor count is 13,100 million for the 660M versus 1,500 million for the HD 7770M. Die size is 208 mm² versus 123 mm², and transistor density is 63.0M per mm² versus 12.2M per mm².

Clock speeds differ: the 660M has a base clock of 1500 MHz and a boost clock of 1900 MHz, while the HD 7770M has no base or boost clock listed. Memory clocks are 1000 MHz with 4 Gbps effective for the HD 7770M, while the 660M uses system shared memory. Memory size is 1024 MB GDDR5 for the HD 7770M versus system shared for the 660M. Bus width is 128-bit for the HD 7770M versus system shared for the 660M. Bandwidth is 64.00 GB/s for the HD 7770M versus system dependent for the 660M.

Shading units: 384 for the 660M, 512 for the HD 7770M. TMUs: 24 versus 32. ROPs are equal at 16 for both. RT cores: 6 for the 660M, none for the HD 7770M. Pixel rate is 30.40 GPixel/s versus 10.80 GPixel/s. Texture rate is 45.60 GTexel/s versus 21.60 GTexel/s. FP32 is 1,459.2 GFLOPS versus 691.2 GFLOPS. The 660M has FP16 performance of 2.918 TFLOPS (2:1), while the HD 7770M has no listed FP16 capability.

TDP is 40 W for the 660M versus 32 W for the HD 7770M. Bus interface is PCIe 4.0 x8 versus PCIe 2.0 x16. DirectX support is 12 Ultimate (12_2) versus 12 (11_1). Vulkan support is 1.4 versus 1.2.170. The 660M is an IGP with no power connectors, while the HD 7770M has no slot width or power connector data. Release dates are 2022 for the 660M and 2012 for the HD 7770M. Predecessors are Vega II IGP for the 660M and Vancouver for the HD 7770M. Successors are Navi III IGP for the 660M and Solar System for the HD 7770M.

Where Each One Wins

The AMD Radeon 660M wins in raw compute throughput, with more than double the FP32 performance of the HD 7770M (1,459.2 GFLOPS vs. 691.2 GFLOPS). It also wins decisively in pixel rate (30.40 GPixel/s vs. 10.80 GPixel/s) and texture rate (45.60 GTexel/s vs. 21.60 GTexel/s). The 660M’s Vulkan score of 14,748 is its strongest benchmark result, indicating that modern API workloads favor the newer architecture. Its 6 nm process and 63.0M transistor density per mm² give it a significant efficiency advantage per unit of silicon. The inclusion of 6 ray tracing cores and DirectX 12 Ultimate support means it is ready for modern rendering features that the HD 7770M cannot handle. Its average benchmark score of 13,812 also edges out the HD 7770M’s 13,536.

The AMD Radeon HD 7770M wins in specific resource counts: it has 512 shading units compared to 384, and 32 TMUs compared to 24. This gives it more parallel execution units, even if each unit is less efficient. It also has dedicated memory: 1024 MB of GDDR5 on a 128-bit bus with 64.00 GB/s of bandwidth, whereas the 660M relies on system-shared memory whose performance is system dependent. For workloads that are sensitive to dedicated memory latency or that cannot rely on fast system RAM, the HD 7770M’s fixed memory subsystem is more predictable. Its TDP is lower at 32 W versus 40 W, making it the more power-frugal option on paper. Its Geekbench Metal score of 13,536 shows it remains competitive on Apple’s API, and its nearest rival comparisons include the GTX 570 at +0.2%, indicating it holds its own against older discrete parts.

The percentile data shows a near tie: 55th percentile for the 660M versus 54th for the HD 7770M. The 660M’s deltaPct against its nearest rival, the RTX A2000 Mobile, is only -0.1%, meaning it essentially matches that professional mobile GPU. The HD 7770M’s deltaPct against the RX 9070 XT is also -0.1%, meaning it too matches a much newer card in synthetic terms. Neither GPU dominates the other in overall standings.

The Verdict

The data points to a close overall performance match, with the AMD Radeon 660M holding a slim edge in average benchmark score (13,812 vs. 13,536) and percentile rank (55 vs. 54). For users who prioritize modern feature support, the 660M is the clear choice: it brings ray tracing, DirectX 12 Ultimate, Vulkan 1.4, and a 6 nm process that enables higher transistor density and more efficient compute. Its FP32 throughput is more than double the HD 7770M’s, and its pixel and texture rates are roughly three and two times higher, respectively. The 660M’s Vulkan score of 14,748 suggests it thrives in modern API workloads.

For users who need deterministic memory performance or who are constrained by power draw, the HD 7770M has arguments in its favor. Its dedicated 1024 MB GDDR5 frame buffer with 64.00 GB/s bandwidth removes reliance on system memory, which is a meaningful distinction for embedded or legacy systems. Its 32 W TDP is lower than the 660M’s 40 W, and its higher shading unit and TMU counts provide more parallel resources for certain compute patterns. Its Metal score of 13,536 shows it remains viable on Apple platforms.

The production timeline is stark: the 660M released in 2022, while the HD 7770M released in 2012. The 660M succeeds the Vega II IGP and precedes the Navi III IGP, while the HD 7770M succeeds Vancouver and precedes Solar System. Both are end-of-life. The 660M’s nearest rival list includes the RX 7900 XT at +0.5% delta, meaning it actually scores slightly higher than that flagship card in this dataset. The HD 7770M’s nearest rival list includes the RX 9070 XT at -0.1%, meaning it essentially ties a much newer enthusiast card. These comparisons are synthetic and should be interpreted cautiously, but they indicate that both GPUs punch above their historical weight class.

Choose the AMD Radeon 660M if you want modern API support, higher compute throughput, ray tracing capability, and the best raw benchmark average. Choose the AMD Radeon HD 7770M if you need dedicated memory, lower power draw, and a larger pool of shading units for parallel workloads. The benchmark results indicate that for most synthetic tests, the 660M is marginally faster, but the HD 7770M is not obsolete. The two GPUs occupy the same performance tier, separated by less than 3% in average score, and the decision should rest on architectural features rather than raw numbers.