Intel Core i5-6350HQ vs Intel Core i7-4558U Comparison

The Intel Core i5-6350HQ and Intel Core i7-4558U are two mobile processors separated by architecture, core counts, and performance tiers. Benchmark data shows the i5-6350HQ winning every head-to-head comparison, with deltas ranging from 42.7% to 43.6% across Cinebench tests. The i5-6350HQ holds an average benchmark score of 1046, placing it in the 29th percentile of all CPUs, while the i7-4558U averages 1038, sitting at the 28th percentile. Despite the i7 branding, the data positions the i5-6350HQ as the clear performance leader in this pairing.

The Verdict

The Intel Core i5-6350HQ is the definitive choice for workloads that benefit from multi-core throughput. Its four physical cores, compared to the i7-4558U's two, deliver a decisive advantage across every measured Cinebench iteration. In Cinebench R23 multi-core, the i5-6350HQ scores 3616 against the i7-4558U's 2532, a 42.8% lead. This gap is consistent across the older R15 and R20 tests, where the i5-6350HQ leads by 42.7% and 42.8%, respectively. For users running render workloads, video encoding, or any parallel batch processing, the i5-6350HQ is the only rational pick from this data.

The i7-4558U, despite its higher base and boost clocks (2.80 GHz and 3.30 GHz versus 2.30 GHz and 3.20 GHz), cannot overcome its two-core limitation. Even in single-core tests, the i5-6350HQ wins by 43.6% in Cinebench R20 (214 vs 149) and 42.9% in Cinebench R23 (510 vs 357). This indicates the Skylake architecture's IPC advantage over Haswell more than compensates for the i7's higher clock speed. The i7-4558U's only redemption is its lower 28W TDP versus 45W, but that does not translate into any benchmark victory.

Given the zero wins for the i7-4558U across five head-to-head tests, the verdict is straightforward. The i5-6350HQ is for anyone who needs raw compute power in a mobile chassis. The i7-4558U may suit a niche of users prioritizing power efficiency over performance, but the data offers no performance scenario where it is preferable. The i5-6350HQ also carries a launch MSRP of $306, while the i7-4558U has no listed launch price in the data.

Head-to-Head Benchmarks

The largest single-score margin appears in Cinebench R20 single-core, where the i5-6350HQ scores 214 versus 149 for the i7-4558U, a delta of 43.6%. This is notable because single-core tests typically favor higher clock speeds; the i7-4558U's 3.30 GHz boost should have narrowed the gap, but the Skylake core's efficiency prevails. The i5-6350HQ's 510 points in Cinebench R23 single-core against 357 for the i7-4558U reinforces this, with a 42.9% advantage.

Multi-core results follow a nearly identical pattern across all three Cinebench versions. In Cinebench R15, the i5-6350HQ posts 364 versus 255, a 42.7% lead. In Cinebench R20, the scores are 1518 and 1063, a 42.8% gap. Cinebench R23 shows 3616 against 2532, again 42.8%. The consistency of these deltas—hovering around 42-43%—suggests the performance difference is structural rather than workload-specific. The i5-6350HQ's four cores, combined with 6 MB of shared L3 cache versus 4 MB on the i7-4558U, provide a proportional advantage that scales linearly with thread count.

The i7-4558U has no wins in this comparison. Its best relative showing is in Cinebench R15 multi-core, where the delta is 42.7%, the smallest margin. Even there, the i5-6350HQ's 364 points dwarf the i7's 255. The i7-4558U does have a Geekbench multi-core score of 1967 and a single-core score of 941, but no comparable Geekbench data exists for the i5-6350HQ in this pack, so those numbers cannot be used for a head-to-head comparison. The available Cinebench data tells a one-sided story.

Architecture Differences

The i5-6350HQ is built on Intel's 14 nm Skylake-H process, while the i7-4558U uses the older 22 nm Haswell-ULT node. This process gap explains much of the performance difference: the 14 nm node allows for a 2,300 million transistor count on a 171 mm² die, versus 1,300 million transistors on 118 mm² for the 22 nm part. The newer node also enables higher clock-for-clock efficiency, which is why the i5-6350HQ wins single-core tests despite a lower boost clock.

Core and cache configurations diverge sharply. The i5-6350HQ has four cores and four threads, with 6 MB of shared L3 cache. The i7-4558U has two cores and four threads (via Hyper-Threading), with only 4 MB of shared L3 cache. Both share the same L1 (64 KB per core) and L2 (256 KB per core) cache sizes. The additional physical cores on the i5-6350HQ are the primary driver of its multi-core dominance; Hyper-Threading on the i7-4558U cannot replicate the throughput of genuine physical cores.

Memory support also differs. The i5-6350HQ supports both DDR3 and DDR4 memory in a dual-channel configuration, with a memory bandwidth of 34.1 GB/s. The i7-4558U is limited to DDR3, with no memory bus or bandwidth data provided in the pack. The i5-6350HQ also features PCIe Gen 3 with 16 lanes (CPU only), while the i7-4558U has no PCIe information listed.

Integrated graphics differentiate the two as well. The i5-6350HQ includes Intel Iris Pro 580, a higher-tier GPU, while the i7-4558U has Intel HD 5100. The i5-6350HQ uses the Intel BGA 1440 socket, whereas the i7-4558U is on Intel BGA 1168. The i5-6350HQ was released on January 23, 2016, and is marked end-of-life, while the i7-4558U launched on June 3, 2013, with no production status specified. Neither chip has an unlocked multiplier.

FAQ

Q: Which processor has better multi-core performance?

A: The Intel Core i5-6350HQ wins all multi-core tests. In Cinebench R23 multi-core, it scores 3616 versus 2532 for the i7-4558U, a 42.8% lead. The same pattern holds in R15 (364 vs 255) and R20 (1518 vs 1063).

Q: Does the i7-4558U win any benchmark?

A: No. The i7-4558U has zero wins across the five head-to-head Cinebench comparisons. The closest margin is 42.7% in Cinebench R15 multi-core, still favoring the i5-6350HQ.

Q: Why does the i5-6350HQ win single-core tests despite the i7-4558U's higher boost clock?

A: The i5-6350HQ's Skylake architecture on a 14 nm node delivers higher IPC than the i7-4558U's Haswell on 22 nm. Despite the i7's 3.30 GHz boost versus 3.20 GHz, the i5-6350HQ scores 214 vs 149 in Cinebench R20 single-core.

Q: How do their cache sizes compare?

A: The i5-6350HQ has 6 MB of shared L3 cache, while the i7-4558U has 4 MB. Both have identical L1 (64 KB per core) and L2 (256 KB per core) caches.

Q: What are the TDP and socket differences?

A: The i5-6350HQ has a 45W TDP and uses Intel BGA 1440. The i7-4558U has a 28W TDP and uses Intel BGA 1168. The i7's lower TDP indicates better power efficiency, but no performance benefit.

Q: Which processor supports DDR4 memory?

A: Only the i5-6350HQ supports DDR4, along with DDR3. The i7-4558U is limited to DDR3. The i5-6350HQ also lists a dual-channel memory bus with 34.1 GB/s bandwidth.

Where Each One Wins

The i5-6350HQ wins every performance category in the data. Its 42.7-43.6% margins across all Cinebench tests make it the superior choice for CPU-intensive tasks like 3D rendering, video transcoding, and scientific computing. The four physical cores and 6 MB L3 cache provide a structural advantage that scales with workload complexity. Users running Cinebench R23 multi-core workloads will see 3616 points from the i5-6350HQ, which is a 42.8% improvement over the i7-4558U's 2532.

The i7-4558U wins only in power efficiency, with a 28W TDP compared to 45W. This makes it a plausible option for ultra-portable designs where thermal headroom is minimal and battery life is prioritized over raw throughput. Its 22 nm process and 1,300 million transistors consume less power, but that advantage does not translate into any benchmark win. The i7-4558U's Geekbench scores of 1967 multi-core and 941 single-core exist, but without a matching i5-6350HQ Geekbench result, they cannot be used to claim superiority.

For users choosing between these two, the data is unambiguous. The i5-6350HQ is the performance king, winning 5 of 5 head-to-head tests. The i7-4558U is a lower-power alternative that sacrifices 42-43% performance in every measured Cinebench test. There is no workload category in the benchmark data where the i7-4558U comes out ahead. The i5-6350HQ's 29th percentile ranking versus 28th for the i7-4558U confirms that both are mid-tier chips overall, but within this pairing, the i5-6350HQ is the only one that delivers competitive compute performance.