Intel Core i7-5775R vs Intel Core i7-7820HK Comparison

The Verdict

The benchmark data presents a close contest between two end-of-life Intel processors, but with a clear split along workload types. The Intel Core i7-7820HK wins the Geekbench tests decisively, taking both the single-core and multi-core versions with margins of 4.5% and 4.4% respectively. The Intel Core i7-5775R, however, wins all six Cinebench tests, though by very narrow margins ranging from 0.8% to 1.1%. The average benchmark score favors the i7-7820HK at 2048 against 2031 for the i7-5775R, placing it in the 46th percentile of all CPUs versus the 45th percentile for its rival.

For users prioritizing Geekbench-style workloads, which often reflect general system responsiveness and certain productivity tasks, the i7-7820HK is the clear choice. For users running Cinebench rendering tasks, the i7-5775R holds a consistent, albeit small, advantage. The i7-7820HK also offers an unlocked multiplier, making it the only one of the two that can be overclocked, a feature that could extend its lead in scenarios where the user adjusts clock settings. The i7-5775R, with its higher base clock of 3.30 GHz versus 2.90 GHz, is the default performer in Cinebench out of the box, but the i7-7820HK's headroom for manual tuning makes it the more flexible option for enthusiasts.

Architecture Differences

The two processors belong to different Intel generations and target different market segments. The i7-7820HK is built on the Kaby Lake architecture, specifically the Kaby Lake-H variant, and is designated as a mobile processor. The i7-5775R uses the older Broadwell architecture and is classified as a desktop processor. Both are manufactured on the same 14 nm process node by Intel, but the die sizes differ significantly: the i7-7820HK has a die size of 126 mm², while the i7-5775R has a larger die at 182 mm².

Core and thread counts are identical: both have 4 cores and 8 threads. Cache configurations differ in the L3 portion. The i7-7820HK has 8 MB of shared L3 cache, while the i7-5775R has 6 MB of shared L3 cache. L1 and L2 caches are the same at 64 KB per core and 256 KB per core respectively. The i7-7820HK supports both DDR3 and DDR4 memory, whereas the i7-5775R supports only DDR3. Both use dual-channel memory buses, but the i7-5775R has a recorded memory bandwidth of 29.9 GB/s, a figure not provided for the i7-7820HK.

Integrated graphics differ as well. The i7-7820HK includes Intel HD Graphics 630, while the i7-5775R includes Iris Pro Graphics 6200. Both processors use PCIe Gen 3 with 16 lanes from the CPU. The i7-7820HK has a TDP of 45 watts, making it more power-efficient on paper than the i7-5775R, which has a TDP of 65 watts. The i7-7820HK has an unlocked multiplier, while the i7-5775R does not. The i7-7820HK uses socket Intel BGA 1440, and the i7-5775R uses Intel BGA 1364.

Head-to-Head Benchmarks

The Cinebench results show a consistent pattern of narrow victories for the i7-5775R. In Cinebench R15 multi-core, the i7-5775R scores 641 against 635 for the i7-7820HK, a delta of -0.9%. In single-core R15, the i7-5775R scores 90 versus 89, a delta of -1.1%. Moving to Cinebench R20, the i7-5775R again leads in multi-core with 2671 versus 2648 (-0.9%) and in single-core with 376 versus 373 (-0.8%). Cinebench R23 follows the same pattern: multi-core shows 6360 for the i7-5775R against 6306 for the i7-7820HK (-0.8%), and single-core shows 897 versus 890 (-0.8%). Across all six Cinebench tests, the i7-5775R's advantage is consistent but never exceeds 1.1%.

The Geekbench results flip the outcome. In Geekbench multi-core, the i7-7820HK scores 4173 against 3996 for the i7-5775R, a delta of 4.4%. In Geekbench single-core, the i7-7820HK scores 1273 against 1218, a delta of 4.5%. These margins are roughly four to five times larger than the Cinebench deltas, making the i7-7820HK's wins in Geekbench more substantial in relative terms.

The recorded data shows the i7-7820HK wins 2 benchmarks total, while the i7-5775R wins 6. The average benchmark score, however, favors the i7-7820HK at 2048 versus 2031, a difference of 17 points. This discrepancy suggests that the magnitudes of the wins matter: the i7-7820HK's Geekbench victories contribute more to its average score than the i7-5775R's Cinebench victories contribute to its own average.

FAQ

Q: Which processor has a higher base clock speed?

A: The Intel Core i7-5775R has a base clock of 3.30 GHz, while the Intel Core i7-7820HK has a base clock of 2.90 GHz.

Q: Does either processor support DDR4 memory?

A: Only the Intel Core i7-7820HK supports DDR4 memory. The Intel Core i7-5775R supports only DDR3.

Q: Which processor has a larger L3 cache?

A: The Intel Core i7-7820HK has 8 MB of shared L3 cache, while the Intel Core i7-5775R has 6 MB of shared L3 cache.

Q: Can either processor be overclocked?

A: The Intel Core i7-7820HK has an unlocked multiplier, enabling overclocking. The Intel Core i7-5775R has a locked multiplier and does not support overclocking.

Q: What are the integrated graphics solutions in each processor?

A: The Intel Core i7-7820HK includes Intel HD Graphics 630, while the Intel Core i7-5775R includes Iris Pro Graphics 6200.

Q: Which processor has a lower TDP?

A: The Intel Core i7-7820HK has a TDP of 45 watts, which is lower than the Intel Core i7-5775R's TDP of 65 watts.

Where Each One Wins

The Intel Core i7-5775R wins all Cinebench tests, which are rendering workloads that stress multi-threaded and single-threaded performance. The margins are small, ranging from 0.8% to 1.1%, but they are consistent across three different versions of Cinebench (R15, R20, and R23). This suggests a slight but reliable edge in CPU rendering tasks. The i7-5775R also has a higher base clock (3.30 GHz versus 2.90 GHz), which likely contributes to its out-of-the-box performance in these tests. Its higher TDP of 65 watts, compared to 45 watts for the i7-7820HK, may indicate a design that prioritizes sustained performance over power efficiency.

The Intel Core i7-7820HK wins both Geekbench tests, with margins of 4.4% in multi-core and 4.5% in single-core. Geekbench is a broader system benchmark that includes memory and integer/floating point tests, so this win suggests the i7-7820HK has an advantage in general-purpose computing tasks. Its larger L3 cache (8 MB versus 6 MB) and support for DDR4 memory likely contribute to this lead. Additionally, the unlocked multiplier means users can push the i7-7820HK further, potentially widening the gap in any workload after manual tuning.

For users who primarily run rendering or CPU-intensive compute tasks, the i7-5775R is the safer default choice. For users who value general system performance, memory flexibility (DDR4 support), or overclocking headroom, the i7-7820HK is the stronger pick. The i7-7820HK also has a lower TDP, making it a more power-efficient option for mobile or compact builds, despite being classified as a mobile processor. The i7-5775R, as a desktop part, may be easier to integrate into standard desktop systems, but its higher power draw and lack of overclocking support limit its flexibility.

Specification Differences

The key specification differences between the two processors are as follows:

• Base Clock: 2.90 GHz (i7-7820HK) versus 3.30 GHz (i7-5775R)
• Boost Clock: 3.90 GHz (i7-7820HK) versus 3.80 GHz (i7-5775R)
• TDP: 45 watts (i7-7820HK) versus 65 watts (i7-5775R)
• Socket: Intel BGA 1440 (i7-7820HK) versus Intel BGA 1364 (i7-5775R)
• Architecture: Kaby Lake (i7-7820HK) versus Broadwell (i7-5775R)
• Generation: Core i7 (Kaby Lake-H) versus Core i7 (Broadwell)
• Die Size: 126 mm² (i7-7820HK) versus 182 mm² (i7-5775R)
• L3 Cache: 8 MB shared (i7-7820HK) versus 6 MB shared (i7-5775R)
• Memory Support: DDR3, DDR4 (i7-7820HK) versus DDR3 (i7-5775R)
• Memory Bandwidth: Not provided (i7-7820HK) versus 29.9 GB/s (i7-5775R)
• Integrated Graphics: Intel HD Graphics 630 (i7-7820HK) versus Iris Pro Graphics 6200 (i7-5775R)
• Market Segment: Mobile (i7-7820HK) versus Desktop (i7-5775R)
• Release Date: January 2017 (i7-7820HK) versus May 2015 (i7-5775R)
• Launch MSRP: $378 (i7-7820HK) versus $384 (i7-5775R)
• Multiplier Unlocked: Yes (i7-7820HK) versus No (i7-5775R)
• Part Number: SR32P (i7-7820HK) versus SR2AL (i7-5775R)

Both processors share identical core counts (4), thread counts (8), L1 cache (64 KB per core), L2 cache (256 KB per core), process node (14 nm), PCIe configuration (Gen 3, 16 lanes), and lack ECC memory support. The i7-7820HK is the newer part by roughly 20 months and carries a slightly lower launch MSRP. The i7-5775R has a higher base clock and a larger die, while the i7-7820HK offers a higher boost clock and more L3 cache.