Intel Core i7-2675QM vs Intel Core i7-975 Comparison

The Intel Core i7-975 and Intel Core i7-2675QM are both four-core, eight-thread processors from Intel, but they target completely different platforms and eras. The i7-975 is a desktop Extreme Edition part built on the older Nehalem architecture, while the i7-2675QM is a mobile chip based on Sandy Bridge. The benchmark data shows a surprisingly consistent picture: the mobile chip wins every single recorded test, despite the desktop part having a much higher base clock and a 130 W TDP. This analysis walks through the head-to-head results, architecture differences, and which processor is better suited for which workload.

Head-to-Head Benchmarks

The recorded data shows a clean sweep. The Intel Core i7-2675QM wins all five head-to-head benchmark comparisons, with the Intel Core i7-975 trailing by margins between 4.6% and 4.9%.

Starting with multi-core performance, the i7-2675QM scores 314 in Cinebench R15 multi-core, beating the i7-975's 299. That is a 4.8% deficit for the desktop chip. The pattern repeats in Cinebench R20 multi-core, where the i7-2675QM posts 1309 versus 1249 for the i7-975, a 4.6% gap. In Cinebench R23 multi-core, the mobile part scores 3118, while the i7-975 manages 2974, again a 4.6% difference. The i7-975 never gets closer than 4.6% in any multi-threaded test, meaning the newer architecture of the mobile chip overcomes its significantly lower clock speeds.

Single-core results tell a similar story. The i7-2675QM records 184 in Cinebench R20 single-core, while the i7-975 scores 175, a 4.9% lead for the mobile chip. In Cinebench R23 single-core, the i7-2675QM scores 440 versus 419, a 4.8% advantage. These single-threaded wins are notable because the i7-975 runs at a 3.33 GHz base clock and a 3.60 GHz boost clock, while the i7-2675QM is much slower on paper at 2.20 GHz base and 3.10 GHz boost. The data indicates that Sandy Bridge's per-clock efficiency more than compensates for the raw clock disadvantage.

When looking at the broader database context, both processors sit at the 28th percentile among all CPUs. The i7-975 has an average benchmark score of 1023, and the i7-2675QM averages 1012. The nearest rivals for the i7-975 include the AMD Ryzen 5 PRO 2500U with an average score of 1024 (0% delta), the AMD Phenom II X6 1075T at 1024 (-0.1%), the Intel Pentium Gold G5600 at 1022 (+0.1%), and the Intel Processor N150 at 1025 (-0.2%). For the i7-2675QM, the closest competitors are the Intel Xeon W5580 at 1012 (0%), the Intel Core i5-2300 at 1014 (-0.2%), the Intel Core i3-7100H at 1009 (+0.3%), and the Intel Processor N100 at 1007 (+0.5%). These rival groups show that both chips land in the same performance tier overall, but the head-to-head data favors the mobile part in every measured workload.

Architecture Differences

The Intel Core i7-975 is built on the Nehalem architecture with the Bloomfield codename, produced on a 45 nm process node at Intel. It contains 731 million transistors on a 263 mm² die. The Intel Core i7-2675QM uses the Sandy Bridge architecture, also with the Sandy Bridge codename, manufactured on a 32 nm process. This newer node packs 1,160 million transistors into a smaller 216 mm² die. The transistor count jump is substantial, and the smaller die size with more transistors reflects a much denser and more advanced manufacturing process.

Cache configurations differ as well. Both chips have 64 KB of L1 cache per core and 256 KB of L2 cache per core. The shared L3 cache, however, is not equal: the i7-975 has 8 MB shared, while the i7-2675QM has 6 MB shared. The desktop part offers more total cache, but the mobile chip still wins every benchmark, which suggests that architectural efficiency matters more than raw cache capacity in these tests.

Memory support also separates the two. The i7-975 uses DDR3 memory with a triple-channel memory bus and a recorded memory bandwidth of 25.6 GB/s. The i7-2675QM uses a dual-channel memory bus, and the database does not record a memory bandwidth figure or memory support type for it. The desktop chip has a clear memory bandwidth advantage on paper, yet the benchmark results do not reflect any benefit in the tested workloads.

The i7-975 is a desktop part with a 130 W TDP, an unlocked multiplier, and no integrated graphics. It uses Intel Socket 1366 and supports PCIe Gen 2. The i7-2675QM is a mobile part with a 45 W TDP, a locked multiplier, and integrated Intel HD 3000 graphics. It uses Intel BGA 1224, and the database does not record PCIe generation support. The i7-975 is marked as Core i7 Extreme (Bloomfield), while the i7-2675QM is marked as Core i7 (Sandy Bridge). The i7-975 was released in 2009, and the i7-2675QM in 2011. Both are end-of-life products.

FAQ

Q: Which processor has the higher boost clock?

A: The Intel Core i7-975 has a boost clock of 3.60 GHz, compared to 3.10 GHz for the Intel Core i7-2675QM.

Q: Does the Intel Core i7-2675QM win any benchmark tests?

A: Yes, the i7-2675QM wins all five recorded head-to-head tests, including Cinebench R15 multi-core, Cinebench R20 multi-core, Cinebench R20 single-core, Cinebench R23 multi-core, and Cinebench R23 single-core.

Q: Which processor has more L3 cache?

A: The Intel Core i7-975 has 8 MB of shared L3 cache, while the Intel Core i7-2675QM has 6 MB of shared L3 cache.

Q: Are both processors still in production?

A: No, both are end-of-life products. The Intel Core i7-975 was released in 2009, and the Intel Core i7-2675QM was released in 2011.

Q: Do both processors have integrated graphics?

A: No. The Intel Core i7-975 has no integrated graphics, while the Intel Core i7-2675QM includes Intel HD 3000.

Q: What is the TDP difference between the two?

A: The Intel Core i7-975 has a TDP of 130 W, while the Intel Core i7-2675QM has a TDP of 45 W.

Specification Differences

The two processors differ across nearly every major specification category. The base clock is a clear separation point: the i7-975 runs at 3.33 GHz, and the i7-2675QM runs at 2.20 GHz. Boost clocks are 3.60 GHz for the desktop part and 3.10 GHz for the mobile part. TDP is dramatically different, 130 W versus 45 W. The socket differs, Intel Socket 1366 for the i7-975 and Intel BGA 1224 for the i7-2675QM.

Architecture and process node also differ. The i7-975 uses Nehalem with the Bloomfield codename, while the i7-2675QM uses Sandy Bridge with the Sandy Bridge codename. The process node moves from 45 nm to 32 nm. Transistor counts are 731 million for the i7-975 and 1,160 million for the i7-2675QM. Die size shrinks from 263 mm² to 216 mm².

Cache differs only in L3 capacity: 8 MB shared on the i7-975 versus 6 MB shared on the i7-2675QM. Memory bus configuration changes from triple-channel to dual-channel. Memory bandwidth is recorded only for the i7-975 at 25.6 GB/s. The i7-975 supports PCIe Gen 2, while the i7-2675QM has no recorded PCIe generation. Integrated graphics are absent on the i7-975 and present as Intel HD 3000 on the i7-2675QM. The i7-975 has an unlocked multiplier, the i7-2675QM does not. Market segment is desktop versus mobile. The launch MSRP for the i7-975 was $1059; no launch MSRP is recorded for the i7-2675QM. Part numbers are SLBEQ for the i7-975 and SR02S for the i7-2675QM.

The Verdict

The benchmark data is unambiguous. The Intel Core i7-2675QM outperforms the Intel Core i7-975 in every recorded test, with margins from 4.6% to 4.9%. This is despite the i7-975 having a higher base clock, a higher boost clock, more L3 cache, and a triple-channel memory bus. The newer Sandy Bridge architecture on a 32 nm process delivers better performance at a fraction of the power draw.

The i7-975's only advantages are structural: it has an unlocked multiplier for overclocking, more L3 cache, higher memory bandwidth, and a desktop platform with a 130 W TDP. None of these translate into a benchmark win in the recorded data. The mobile chip is strictly faster in the tested workloads, and it does so with a 45 W TDP, making it far more power-efficient.

For anyone choosing between these two based on the database results, the i7-2675QM is the better performer. The i7-975 remains relevant only if the desktop platform, overclocking capability, or triple-channel memory configuration matters more than raw benchmark performance, but the data shows no scenario where it wins a compute test.

Where Each One Wins

The Intel Core i7-2675QM wins every measured multi-core and single-core workload. In Cinebench R15 multi-core, it leads by 4.8%. In Cinebench R20 multi-core and R23 multi-core, it leads by 4.6% in both. In single-core tests, it leads by 4.9% in R20 and 4.8% in R23. If the workload is rendering, compilation, or any heavily threaded task represented by Cinebench, the data says the mobile chip is faster. If the workload is lightly threaded, the same conclusion applies.

The Intel Core i7-975 does not win any recorded benchmark. Its strengths lie outside the tested metrics: it offers a triple-channel memory bus with 25.6 GB/s of bandwidth, 8 MB of shared L3 cache, an unlocked multiplier, and a desktop socket with support for PCIe Gen 2. These features could matter for a system that prioritizes memory bandwidth, overclocking, or expansion options, but the database does not contain a single test where the i7-975 comes out ahead.

The practical takeaway is straightforward. For pure compute performance as measured by Cinebench, the i7-2675QM is the pick. For a desktop build where the platform, overclocking headroom, and memory bandwidth are the priorities, the i7-975 has a reason to exist, but not a performance one. The recorded data shows a mobile chip from 2011 beating a desktop Extreme Edition from 2009 in every single benchmark, which is a clear demonstration of how much architectural progress mattered in that period.