CPU Comparison

The Intel Core i5-5675C and Intel Core i5-6600 are two desktop processors from the same generation era, but they represent distinctly different engineering priorities. The 5675C is a Broadwell part with an unlocked multiplier and a high-end integrated GPU, while the 6600 is a Skylake chip with a lower TDP and higher clock speeds. The benchmark data shows a clear split: the i5-6600 dominates in rendering workloads, while the i5-5675C takes a decisive lead in Geekbench tests. This analysis walks through the head-to-head results, the architectural reasons for the divergence, and the practical implications for which processor suits which task.

Head-to-Head Benchmarks

The most striking pattern in the head-to-head data is that the two processors never trade places within the same benchmark family. In all three Cinebench versions (R15, R20, and R23), the Intel Core i5-6600 wins every single-core and multi-core test. The margins are consistent and narrow, hovering around 4.6% to 5.5%. In Cinebench R15 multi-core, the i5-6600 scores 520 against the i5-5675C's 495, a delta of -4.8%. The single-core R15 result is similar: 73 versus 69, a 5.5% gap. This trend persists into R20 and R23, where the multi-core deltas are again -4.8% (2167 vs 2063 and 5161 vs 4912, respectively). The R20 single-core test shows the smallest margin at -4.6% (305 vs 291), while R23 single-core matches the multi-core delta at -4.8% (728 vs 693). Across the board, the i5-6600 holds a steady advantage of roughly five percent in Cinebench.

The Geekbench results flip the narrative entirely. Here, the Intel Core i5-5675C is the clear winner, and by a much larger margin than the i5-6600's Cinebench lead. In Geekbench multi-core, the 5675C scores 4159 against the 6600's 3755, a delta of 10.8%. The single-core test is even more lopsided: 1388 versus 1239, a 12% advantage for the 5675C. This is a significant reversal. The i5-5675C wins two benchmarks total, and both are Geekbench tests. The i5-6600 wins six benchmarks, all of which are Cinebench variants. The magnitude of the Geekbench wins (over 10%) is roughly double the magnitude of the Cinebench wins (under 6%), meaning the 5675C's victories are more decisive in percentage terms, even though it loses the count of benchmark wins.

Looking at the average benchmark scores, the two processors are nearly identical overall. The i5-5675C has an average score of 1759, while the i5-6600 sits at 1744. The nearest rivals data puts this in context: the 5675C is within 0.2% of the Intel Xeon E3-1241 v3 (1756) and 0.2% ahead of the Intel Core i7-4790T (1755), while trailing the AMD Ryzen 5 2400GE (1766) by 0.4%. The 6600 is 0.1% behind the Intel Core i7-980X (1746) and 0.1% ahead of both the AMD Ryzen 3 4300U and the Intel Core i3-10100 (both 1742). Both chips land in the 41st percentile of all CPUs, meaning they are statistically equivalent in aggregate performance, with the differences concentrated in specific workload types.

Architecture Differences

The two processors are built on the same 14 nm process node and both use Intel's manufacturing foundry, but the underlying architectures diverge significantly. The i5-5675C uses the Broadwell architecture (codename Broadwell), while the i5-6600 uses Skylake (codename Skylake). This generation gap explains many of the benchmark differences. The i5-5675C is part of the "Core i5 (Broadwell)" generation, whereas the i5-6600 belongs to the "Core i5 (Skylake)" generation. Despite the newer architecture name, the i5-6600 has a smaller die size at 177 mm², compared to the 5675C's 182 mm².

Cache configuration is a major differentiator. Both processors have 64 KB of L1 cache per core and 256 KB of L2 cache per core, but the L3 cache differs: the i5-5675C has 4 MB of shared L3 cache, while the i5-6600 has 6 MB of shared L3 cache. This 50% increase in L3 cache for the 6600 likely contributes to its Cinebench advantage, as rendering workloads can benefit from larger cache pools. The i5-5675C compensates with a significantly more powerful integrated GPU: Iris Pro Graphics 6200 versus the i5-6600's UHD Graphics 530. The 5675C's GPU is a notable feature for a desktop part, which is typical of the Broadwell "C" series that prioritized graphics performance.

Memory support also differs. The i5-5675C supports only DDR3, while the i5-6600 supports both DDR3 and DDR4. The memory bus is dual-channel for both, but the memory bandwidth numbers tell a different story: the 6600 offers 34.1 GB/s, while the 5675C is limited to 25.6 GB/s. This 33% bandwidth advantage for the 6600 aligns with its newer memory controller and could factor into its rendering performance. The i5-5675C uses Socket 1150, while the i5-6600 uses Socket 1151, meaning they are not interchangeable on motherboards. Both support PCIe Gen 3 with 16 lanes (CPU only), and neither supports ECC memory.

Another key difference is the unlock status. The i5-5675C has an unlocked multiplier, making it overclockable, while the i5-6600 is locked. This is a notable feature for the 5675C, as it allows users to potentially close the clock speed gap. The base clock and boost clock also favor the 6600: 3.30 GHz base and 3.90 GHz boost for the 6600, versus 3.10 GHz base and 3.60 GHz boost for the 5675C. The TDP is a significant differentiator as well: the 6600 is rated at 35W, which is remarkably low for a desktop quad-core, while the 5675C is rated at 65W. The 6600's much lower TDP suggests it runs cooler and more efficiently, which is consistent with its Skylake design.

Where Each One Wins

The benchmark data draws a clear line between workload types. The Intel Core i5-6600 wins every Cinebench test, which measures rendering performance in Cinema 4D. Multi-core Cinebench results show a consistent 4.8% lead for the 6600 across R15, R20, and R23, indicating that its higher clock speeds and larger L3 cache translate directly into better rendering throughput. Single-core Cinebench results also favor the 6600, with deltas ranging from 4.6% to 5.5%, suggesting that its 3.90 GHz boost clock provides a real advantage in lightly-threaded rendering tasks. The 6600 also has a lower TDP (35W vs 65W), making it the more power-efficient choice for sustained workloads.

The Intel Core i5-5675C wins both Geekbench tests, which are more general-purpose system benchmarks that exercise a mix of integer, floating-point, and memory operations. The 5675C's 10.8% multi-core advantage and 12% single-core advantage are substantial and cannot be explained by clock speed alone, since the 6600 has higher clocks. The 5675C's Iris Pro Graphics 6200 likely plays a role in Geekbench's compute tests, as the integrated GPU can accelerate certain workloads. The unlocked multiplier on the 5675C also means that users can overclock it, potentially extending its lead in Geekbench-style tasks.

For use cases, the 6600 is the better choice for 3D rendering, video encoding, and any task that relies on the Cinebench-style workload pattern. Its larger L3 cache and higher memory bandwidth (34.1 GB/s vs 25.6 GB/s) give it an edge in data-heavy operations. The 5675C, on the other hand, is better suited for general system responsiveness and tasks that Geekbench models, including web browsing, office productivity, and light content creation. Its superior integrated graphics make it a stronger option for systems without a discrete GPU, particularly for casual gaming or GPU-accelerated applications. The 5675C's unlocked multiplier also appeals to users who want to overclock, while the 6600's 35W TDP makes it ideal for low-power builds.

FAQ

Q: Which processor has a higher single-core Cinebench R23 score?

A: The Intel Core i5-6600 wins with a score of 728, compared to the i5-5675C's 693, a delta of -4.8%.

Q: How much faster is the i5-5675C in Geekbench single-core?

A: The i5-5675C scores 1388, which is 12% higher than the i5-6600's 1239.

Q: Do both processors support the same memory types?

A: No. The i5-5675C supports only DDR3, while the i5-6600 supports both DDR3 and DDR4.

Q: What is the TDP difference between the two?

A: The i5-5675C has a TDP of 65W, while the i5-6600 has a TDP of 35W.

Q: Which processor has an unlocked multiplier?

A: The i5-5675C has an unlocked multiplier, while the i5-6600 is locked.

Q: What are the average benchmark scores for each?

A: The i5-5675C has an average score of 1759, and the i5-6600 has an average score of 1744.

Specification Differences

The two processors differ in several key specifications. The base clock is 3.10 GHz for the i5-5675C and 3.30 GHz for the i5-6600. The boost clock is 3.60 GHz for the 5675C and 3.90 GHz for the 6600. The TDP is 65W for the 5675C and 35W for the 6600. The socket is Intel Socket 1150 for the 5675C and Intel Socket 1151 for the 6600. The architecture is Broadwell for the 5675C and Skylake for the 6600. The die size is 182 mm² for the 5675C and 177 mm² for the 6600. The L3 cache is 4 MB for the 5675C and 6 MB for the 6600. Memory support is DDR3 only for the 5675C and DDR3/DDR4 for the 6600. Memory bandwidth is 25.6 GB/s for the 5675C and 34.1 GB/s for the 6600. The integrated graphics are Iris Pro Graphics 6200 for the 5675C and UHD Graphics 530 for the 6600. The multiplier is unlocked for the 5675C and locked for the 6600. The production status is "Active" for the 5675C and "End-of-life" for the 6600. The launch MSRP is $276 for the 5675C and $224 for the 6600.

The Verdict

The data supports a straightforward recommendation based on workload priority. The Intel Core i5-6600 is the better choice for rendering and compute-heavy tasks, as evidenced by its consistent 4.6% to 5.5% lead across all Cinebench tests. Its higher clock speeds (3.30 GHz base, 3.90 GHz boost), larger 6 MB L3 cache, and higher memory bandwidth (34.1 GB/s) make it the stronger performer in multi-threaded rendering. The 6600 also offers a significantly lower TDP of 35W versus 65W, making it the more efficient option for compact or passively cooled systems. Its support for both DDR3 and DDR4 memory provides more flexibility in system building. However, the 6600 is end-of-life and has a locked multiplier, limiting its upgrade and overclocking potential.

The Intel Core i5-5675C is the better choice for general-purpose computing and integrated graphics performance. Its 10.8% multi-core and 12% single-core wins in Geekbench indicate superior performance in everyday tasks like web browsing, office applications, and light productivity. The Iris Pro Graphics 6200 is a more capable integrated GPU than the UHD Graphics 530, making the 5675C a better fit for systems without a discrete graphics card. The unlocked multiplier allows for overclocking, which could close the gap in Cinebench workloads if the user is willing to invest in cooling. The 5675C remains active in production status, suggesting ongoing availability. Ultimately, the choice comes down to whether rendering performance (6600) or general system responsiveness and graphics capability (5675C) matters more, with the average benchmark scores showing they are nearly equal overall.