Intel Core i7-2920XM vs Intel Core i7-875K Comparison

Intel Core i7-2920XM and Intel Core i7-875K are both end-of-life quad-core processors from Intel, but they target different platforms and eras. The 2920XM is a mobile Extreme Edition part from the Sandy Bridge generation, while the 875K is a desktop Lynnfield chip from the previous Nehalem architecture. Benchmark data shows a clear split: the mobile chip dominates Cinebench workloads, while the desktop chip wins in Geekbench tests. Both sit at the 27th percentile against all CPUs in the database, with average benchmark scores of 995 for the 2920XM and 984 for the 875K.

Head-to-Head Benchmarks

The most striking pattern in the recorded data is the consistency of the Cinebench results. The Intel Core i7-2920XM wins all four Cinebench comparisons by nearly identical margins. In Cinebench R15 multicore, the 2920XM scores 353 against 275 for the 875K, a 28.4% advantage. The same 28.4% delta appears in Cinebench R20 multicore, where the scores are 1471 and 1146 respectively. Cinebench R23 multicore follows the same trend: 3504 for the 2920XM versus 2729 for the 875K, again a 28.4% lead. Single-core Cinebench results are equally lopsided. In R20 single-core, the 2920XM posts 207 versus 161, a 28.6% gap. In R23 single-core, the scores are 494 and 385, a 28.3% lead for the 2920XM. These numbers indicate that across multi-threaded and single-threaded rendering workloads, the Sandy Bridge mobile chip holds a commanding edge.

The Geekbench results flip the script. In Geekbench multicore, the Intel Core i7-875K scores 1696 against 1452 for the 2920XM. That is a 14.4% win for the desktop chip. In Geekbench single-core, the 875K scores 499 versus 430, a 13.8% advantage. This creates an unusual situation where the older desktop processor outperforms the newer mobile processor in one benchmark suite, while losing decisively in another. The overall win count favors the 2920XM, which takes 5 of the 7 head-to-head tests. The 875K takes the remaining 2. The average benchmark score difference is modest: 995 for the 2920XM versus 984 for the 875K, a difference of 11 points. The nearest rival for the 2920XM is the Intel Core i7-2635QM and AMD Opteron 4226, both with an average score of 995 and a 0% delta. The Intel Core i3-8130U is 0.1% behind at 994. For the 875K, the closest competitor is the Intel Core i3-4130T at 984 with a 0% delta, followed by the Intel Xeon X3470 at 983 with a 0.1% deficit and the Intel Xeon W5590 at 986 with a 0.2% advantage.

Architecture Differences

The two processors come from different architectural families. The Intel Core i7-2920XM uses Sandy Bridge architecture on a 32 nm process node. The Intel Core i7-875K uses Nehalem architecture (codename Lynnfield) on a 45 nm process node. This process shrink is significant: the 2920XM packs 1,160 million transistors on a 216 mm² die, while the 875K contains 774 million transistors on a 296 mm² die. The newer process allows the mobile chip to fit more transistors in a smaller area, which contributes to its efficiency and performance characteristics.

Both processors have 4 cores and 8 threads, with identical cache layouts: 64 KB of L1 cache per core, 256 KB of L2 cache per core, and 8 MB of shared L3 cache. The base clocks differ, with the 875K running at 2.93 GHz compared to 2.50 GHz for the 2920XM. Boost clocks are closer, with the 875K at 3.60 GHz and the 2920XM at 3.50 GHz. Both have unlocked multipliers, allowing overclocking. The 2920XM has a TDP of 55 watts, while the 875K draws 95 watts. This is a major difference given the 2920XM is a mobile part designed for laptops, while the 875K is a desktop chip.

Memory support is DDR3 for both, but the memory bandwidth differs. The 2920XM supports dual-channel memory with 25.6 GB/s bandwidth. The 875K also supports dual-channel DDR3, but with 21.3 GB/s bandwidth. Neither supports ECC memory. Both use PCIe Gen 2 with 16 lanes from the CPU. The sockets are incompatible: the 2920XM uses Intel Socket G2 (988B) for mobile platforms, while the 875K uses Intel Socket 1156 for desktop boards. The 2920XM includes integrated graphics with Intel HD 3000; the 875K has no integrated graphics. The part numbers are SR02E for the 2920XM and SLBS2 for the 875K. The market segments are mobile for the 2920XM and desktop for the 875K.

Where Each One Wins

The Intel Core i7-2920XM is the clear winner in rendering and content-creation workloads. The Cinebench suite, which tests CPU rendering performance, shows a consistent 28% advantage across all versions of the test. This applies to both multicore and single-core tests, meaning the 2920XM is not just faster when all cores are busy, but also when a single thread is the bottleneck. The 28.4% margin in Cinebench R15, R20, and R23 multicore, plus the 28.3% to 28.6% margins in single-core tests, point to a fundamental architectural efficiency gain from the Sandy Bridge design. For users running CPU-based rendering, video encoding, or any workload that resembles Cinebench, the 2920XM is the stronger part.

The Intel Core i7-875K wins in Geekbench, which is a more general-purpose benchmark that tests a mix of integer, floating-point, and memory operations. The 875K leads by 14.4% in multicore and 13.8% in single-core. This suggests that in everyday applications that are not heavily threaded rendering tasks, the desktop chip may feel snappier. The higher base clock of 2.93 GHz versus 2.50 GHz likely contributes to this, as does the desktop platform's more robust power delivery. The 875K also has a higher boost clock at 3.60 GHz versus 3.50 GHz. For users who prioritize general responsiveness over rendering throughput, the 875K has the edge in the recorded data.

The overall benchmark average favors the 2920XM, with a score of 995 versus 984 for the 875K. This is a small margin of about 1.1%, but it reflects the mobile chip's dominance in the heavier Cinebench workloads. The 2920XM wins 5 out of 7 head-to-head tests, while the 875K wins 2. However, the benchmark suite is weighted toward Cinebench, which has four tests, versus Geekbench's two tests. The 875K wins both Geekbench tests, while the 2920XM wins all four Cinebench tests. This split means the choice depends heavily on the intended workload.

FAQ

Q: Which processor is faster in Cinebench R23 multicore?

A: The Intel Core i7-2920XM scores 3504, which is 28.4% higher than the Intel Core i7-875K's score of 2729.

Q: Does the Intel Core i7-875K win any benchmark?

A: Yes, the 875K wins both Geekbench tests. It scores 1696 in multicore versus 1452 for the 2920XM, a 14.4% lead, and 499 in single-core versus 430, a 13.8% lead.

Q: What are the TDP ratings for these CPUs?

A: The Intel Core i7-2920XM has a TDP of 55 watts, while the Intel Core i7-875K has a TDP of 95 watts.

Q: Do both processors have integrated graphics?

A: No. The Intel Core i7-2920XM includes Intel HD 3000 graphics, while the Intel Core i7-875K has no integrated graphics.

Q: How do they compare in average benchmark score?

A: The 2920XM has an average benchmark score of 995, while the 875K has an average of 984. The 2920XM is 1.1% higher.

Q: Are both processors unlocked for overclocking?

A: Yes, both the Intel Core i7-2920XM and the Intel Core i7-875K have unlocked multipliers.

Specification Differences

The two processors differ in several key specifications. The process node is 32 nm for the 2920XM and 45 nm for the 875K. Transistor count is 1,160 million for the 2920XM versus 774 million for the 875K. Die size is 216 mm² for the 2920XM and 296 mm² for the 875K. Base clock is 2.50 GHz for the 2920XM and 2.93 GHz for the 875K. Boost clock is 3.50 GHz for the 2920XM and 3.60 GHz for the 875K. TDP is 55 watts for the 2920XM and 95 watts for the 875K. The socket is Intel Socket G2 (988B) for the 2920XM and Intel Socket 1156 for the 875K. Architecture is Sandy Bridge for the 2920XM and Nehalem for the 875K. Memory bandwidth is 25.6 GB/s for the 2920XM and 21.3 GB/s for the 875K. Integrated graphics are present on the 2920XM with Intel HD 3000, but absent on the 875K. Market segment is mobile for the 2920XM and desktop for the 875K. Release dates differ, with the 2920XM releasing in January 2011 and the 875K in May 2010. The launch MSRP is $1096 for the 2920XM and $353 for the 875K. Part numbers are SR02E for the 2920XM and SLBS2 for the 875K.

The Verdict

The data presents a clear split. For rendering workloads measured by Cinebench, the Intel Core i7-2920XM is the superior processor. It delivers a consistent 28% advantage across all Cinebench tests, both multicore and single-core. This is a substantial margin that would be noticeable in any CPU-bound rendering task. The 2920XM achieves this despite having a lower base clock and being a mobile part, thanks to the architectural improvements in Sandy Bridge and the 32 nm process. It also uses significantly less power, with a 55 watt TDP versus 95 watts for the 875K.

For general-purpose performance as measured by Geekbench, the Intel Core i7-875K wins. The 14.4% multicore and 13.8% single-core leads suggest that in everyday computing tasks, the older desktop chip may feel more responsive. The higher base and boost clocks of the 875K likely play a role here. However, the overall average benchmark score still favors the 2920XM at 995 versus 984.

The choice should be based on the intended use case. If the workload is primarily rendering, video encoding, or other Cinebench-like tasks, the 2920XM is the better pick based on its 28% advantage. If the workload is more general-purpose, with a mix of applications that resemble Geekbench, the 875K offers better performance. The 875K also has the practical advantage of being a desktop part, which means it can be paired with standard desktop cooling and power delivery. The 2920XM requires a mobile platform with Socket G2, which limits its applicability. Both processors are end-of-life, so availability is limited, but the benchmark data shows that the 2920XM is the stronger all-around performer in the majority of tests, winning 5 out of 7 head-to-head comparisons.