Intel Core i7-4558U vs Intel Core i7-975 Comparison

Intel Core i7-4558U and Intel Core i7-975 represent two very different eras of Intel design, separated by four years of architectural evolution and aimed at opposite ends of the market. The recorded data shows a clear overall winner in raw compute performance, but the story is more nuanced when considering thermal and platform characteristics. The benchmark results position both processors at the 28th percentile among all CPUs, indicating that while they are not modern powerhouses, they remain competitive in their respective niches.

Head-to-Head Benchmarks

The head-to-head benchmark results are unambiguous: the Intel Core i7-975 wins all five recorded tests, with a consistent performance advantage ranging from 14.7% to 14.9% over the Intel Core i7-4558U. The most significant gap appears in Cinebench R20 single-core, where the i7-975 scores 175 against the i7-4558U's 149, a delta of 14.9%. This pattern repeats across every workload, suggesting a fundamental throughput advantage rather than a workload-specific strength.

In multi-threaded workloads, the i7-975 extends its lead. Cinebench R15 multicore shows the i7-975 at 299 points versus 255 for the i7-4558U, a 14.7% difference. The gap remains nearly identical in R20 multicore, with scores of 1249 and 1063 respectively, again a 14.9% delta. Cinebench R23 multicore follows the same trend: the i7-975 scores 2974, while the i7-4558U scores 2532, a 14.9% advantage. The single-core R23 test shows the i7-975 at 419 versus 357 for the i7-4558U, a 14.8% gap.

These consistent deltas across all tests indicate that the i7-975's advantage is not tied to any particular instruction mix or cache-sensitive workload. The i7-4558U, despite its newer Haswell architecture, cannot overcome the i7-975's raw execution resources. The average benchmark scores reflect this overall relationship: the i7-4558U averages 1038 across all recorded tests, while the i7-975 averages 1023. This apparent contradiction, where the i7-975 wins every head-to-head test but has a slightly lower average, stems from the inclusion of additional Geekbench tests in the i7-4558U's benchmark suite that are not present in the i7-975's record.

The nearest rivals for each processor further contextualize their standing. The i7-4558U sits within 0.3% of the AMD Ryzen 7 PRO 3700U and within 0.4% of the AMD A10-9700, showing it competes with a mix of older and newer mid-range parts. The i7-975, meanwhile, is effectively tied with the AMD Ryzen 5 PRO 2500U at a 0% delta and sits within 0.2% of the Intel Processor N150. This places both chips in a similar performance tier despite their architectural differences.

Architecture Differences

The architectural gap between these two processors is substantial, spanning two distinct design philosophies. The Intel Core i7-4558U uses the Haswell architecture, specifically the Haswell-ULT variant, built on a 22 nm process node. It packs 1,300 million transistors into a 118 mm² die. The i7-975, in contrast, uses the older Nehalem architecture, codenamed Bloomfield, manufactured on a 45 nm process with 731 million transistors spread across a much larger 263 mm² die. This process advantage allows the i7-4558U to deliver its performance at a fraction of the power envelope.

Core configuration is a primary differentiator. The i7-4558U offers 2 physical cores with 4 threads, while the i7-975 provides 4 physical cores with 8 threads. This doubling of compute resources directly explains the i7-975's consistent lead in multi-threaded benchmarks. Both processors share the same per-core L1 cache at 64 KB and L2 cache at 256 KB, but the shared L3 cache differs significantly: the i7-4558U has 4 MB shared, while the i7-975 has 8 MB shared. The larger cache on the i7-975 provides additional headroom for data-intensive workloads.

Clock speeds also favor the i7-975. Its base clock of 3.33 GHz and boost clock of 3.60 GHz exceed the i7-4558U's 2.80 GHz base and 3.30 GHz boost. This higher operating frequency, combined with more cores, gives the i7-975 a dual advantage in both single-threaded and multi-threaded scenarios. The i7-4558U's boost clock of 3.30 GHz cannot compensate for having half the cores and a lower base frequency.

The thermal and platform characteristics are starkly opposed. The i7-4558U is a mobile processor with a 28 W TDP, designed for thin laptops with limited cooling. The i7-975 is a desktop part with a 130 W TDP, intended for high-performance desktop systems with robust cooling solutions. This 102 W difference in thermal design power reflects the entirely different usage contexts. The i7-4558U uses the Intel BGA 1168 socket, while the i7-975 uses Intel Socket 1366, and the i7-975 also includes an unlocked multiplier, a feature absent on the i7-4558U.

Memory support shows further divergence. Both support DDR3, but the i7-975 implements triple-channel memory with a 25.6 GB/s memory bandwidth, while the i7-4558U's memory bus configuration is not specified in the recorded data. The i7-975 also exposes PCIe Gen 2, while the i7-4558U's PCIe support is unlisted. Neither processor supports ECC memory. Integrated graphics are present only on the i7-4558U, which includes Intel HD 5100, while the i7-975 has no integrated graphics and requires a discrete GPU.

Where Each One Wins

The Intel Core i7-975 wins every recorded benchmark, making it the clear choice for raw computational throughput. Its 4-core, 8-thread configuration delivers a 14.7% to 14.9% advantage across all Cinebench tests, both single-core and multi-core. This makes it the superior option for desktop workloads that can leverage multiple threads, such as video encoding, 3D rendering, and software compilation. The 8 MB L3 cache and triple-channel memory bandwidth further enhance its suitability for data-heavy applications. Its unlocked multiplier also provides overclocking headroom, a feature that can extend its performance beyond stock levels in appropriately cooled systems.

The Intel Core i7-4558U, despite losing all head-to-head comparisons, has clear advantages in specific contexts. Its 28 W TDP makes it dramatically more power-efficient than the i7-975's 130 W TDP, a crucial factor for mobile platforms. The integrated Intel HD 5100 graphics eliminate the need for a separate GPU in basic display and media tasks, which the i7-975 cannot offer. The i7-4558U's 22 nm process and smaller die size contribute to its suitability for compact laptop designs where space and thermal management are paramount. In the database's recorded data, the i7-4558U includes Geekbench scores of 1967 multicore and 941 singlecore, tests that the i7-975's record lacks, indicating a broader benchmark profile for the mobile part.

For a user prioritizing performance in a desktop context, the i7-975 is the definitive winner based on the recorded data. For a user prioritizing portability, power consumption, and integrated graphics in a laptop, the i7-4558U is the only viable option among these two, despite its lower raw performance. The i7-4558U's release date of June 2013 and the i7-975's release date of June 2009 also reflect their intended market positions: the i7-975 was a high-end desktop flagship at its launch, while the i7-4558U was a mid-range mobile part four years later.

FAQ

Q: Which processor is faster in multi-core workloads?

A: The Intel Core i7-975 is consistently faster, winning all multi-core tests by 14.7% to 14.9%. It scores 299 in Cinebench R15, 1249 in R20, and 2974 in R23, while the i7-4558U scores 255, 1063, and 2532 respectively.

Q: How do the two processors compare in single-core performance?

A: The i7-975 also wins single-core tests, scoring 175 in Cinebench R20 single-core versus 149 for the i7-4558U, and 419 in R23 single-core versus 357, a 14.8% to 14.9% advantage.

Q: What are the core and thread counts for each processor?

A: The Intel Core i7-4558U has 2 cores and 4 threads, while the Intel Core i7-975 has 4 cores and 8 threads.

Q: Do both processors support the same memory type?

A: Yes, both support DDR3 memory. However, the i7-975 uses triple-channel memory with 25.6 GB/s bandwidth, while the i7-4558U's memory bus configuration is not specified in the recorded data.

Q: Which processor includes integrated graphics?

A: Only the Intel Core i7-4558U includes integrated graphics, specifically Intel HD 5100. The Intel Core i7-975 has no integrated graphics.

Q: What are the thermal design power ratings for these processors?

A: The Intel Core i7-4558U has a TDP of 28 W, while the Intel Core i7-975 has a TDP of 130 W.

Specification Differences

The recorded specifications reveal several key differences between the two processors. The Intel Core i7-4558U has 2 cores and 4 threads, while the Intel Core i7-975 has 4 cores and 8 threads. Base clock speeds are 2.80 GHz for the i7-4558U and 3.33 GHz for the i7-975, with boost clocks of 3.30 GHz and 3.60 GHz respectively. Thermal design power differs substantially: 28 W for the i7-4558U versus 130 W for the i7-975.

The i7-4558U uses the Intel BGA 1168 socket and has a 22 nm process node with 1,300 million transistors on a 118 mm² die. The i7-975 uses Intel Socket 1366 and has a 45 nm process node with 731 million transistors on a 263 mm² die. L3 cache is 4 MB shared on the i7-4558U versus 8 MB shared on the i7-975. The i7-4558U includes Intel HD 5100 integrated graphics, while the i7-975 has no integrated graphics. The i7-975 supports triple-channel DDR3 memory with 25.6 GB/s bandwidth and PCIe Gen 2, while the i7-4558U's memory bus and PCIe support are not listed.

The i7-975 has an unlocked multiplier, whereas the i7-4558U does not. The i7-4558U is classified as a Mobile segment processor with a release date of June 2013, while the i7-975 is a Desktop segment processor with a release date of June 2009. The i7-975 is marked as end-of-life production status, and its launch MSRP was $1059. The i7-4558U has no recorded launch MSRP. Neither processor supports ECC memory. The part numbers are SR188 for the i7-4558U and SLBEQ for the i7-975.