Intel Core i5-4590S vs Intel Core i7-8665U Comparison

The Intel Core i7-8665U and Intel Core i5-4590S are both quad-core Intel processors, but they target entirely different market segments: the former is a low-power mobile chip from the Whiskey Lake generation, while the latter is a higher-power desktop part from the Haswell era. Benchmark data shows a consistent victory for the i7-8665U across all tested Cinebench workloads, with a 20.6% lead in multi-core tests and a 21.3% lead in the R15 single-core test, despite the i5-4590S having a higher base clock of 2.90 GHz compared to 1.90 GHz. The i7-8665U leverages its newer architecture, higher boost clock of 4.80 GHz, and Hyper-Threading to overcome the i5-4590S's clock advantage, making it the stronger performer in every measured metric.

FAQ

Q: Which processor is faster in multi-core Cinebench R23?

A: The Intel Core i7-8665U scores 5232, which is 20.6% higher than the Intel Core i5-4590S's 4338. This consistent 20.6% delta is also seen in Cinebench R15 and R20 multi-core tests.

Q: How do the single-core performances compare?

A: The i7-8665U wins all single-core tests. In Cinebench R15, it scores 74 versus 61, a 21.3% advantage; in R20 it scores 309 versus 257, a 20.2% lead; and in R23 it scores 738 versus 612, a 20.6% lead.

Q: What is the difference in thread count between the two?

A: The i7-8665U has 8 threads (4 cores with Hyper-Threading), while the i5-4590S has only 4 threads (4 cores without Hyper-Threading). This directly contributes to the i7's multi-core advantage.

Q: How does the boost clock differ between the two chips?

A: The i7-8665U has a maximum boost clock of 4.80 GHz, which is significantly higher than the i5-4590S's 3.60 GHz boost clock. This helps the mobile chip overcome its lower base clock.

Q: What are the TDP ratings for these processors?

A: The i7-8665U is rated at 15 W, making it suitable for thin-and-light laptops, while the i5-4590S is rated at 65 W, indicating a desktop-oriented power envelope.

Q: Which chip has a better integrated GPU?

A: The i7-8665U features UHD Graphics 620, while the i5-4590S has Intel HD 4600. The i7's newer integrated graphics architecture is part of its Whiskey Lake platform.

Where Each One Wins

The benchmark data is unambiguous: the Intel Core i7-8665U wins every single head-to-head test recorded. Out of six Cinebench comparisons (R15, R20, and R23, each with single- and multi-core variants), the i7-8665U takes all six. The i5-4590S does not win a single test, making this a one-sided comparison.

However, the use-case split is not just about raw benchmark scores. The i7-8665U is a mobile processor with a 15 W TDP, designed for laptops and ultrabooks where power efficiency is paramount. Its high boost clock of 4.80 GHz allows it to deliver strong burst performance for everyday tasks and light productivity, while its 8 threads handle multitasking more smoothly than the i5-4590S.

The i5-4590S, on the other hand, is a desktop chip with a 65 W TDP. Its advantage lies in its platform: it uses the Intel Socket 1150, which is associated with desktop motherboards that offer more expansion options, better cooling, and upgrade paths. For a desktop user with an existing 1150 board, the i5-4590S provides a serviceable quad-core experience, but its 4 threads and lower boost clock place it behind the i7-8665U in all measured workloads.

The i7-8665U's 20.6% multi-core lead means it is better suited for modern, threaded workloads like video encoding or compiling, where its Hyper-Threading provides a tangible benefit. The i5-4590S's only potential edge is in scenarios where sustained all-core load is required, but the 65 W TDP does not translate into a performance win in the data—the i7-8665U remains faster even in multi-core tests that would typically favor a higher-power desktop part.

Architecture Differences

The two processors come from different eras of Intel's design. The i7-8665U is built on Whiskey Lake, specifically the Whiskey Lake-U codename, using a 14 nm process node. It belongs to the Core i7 (Whiskey Lake) generation and was released in 2018. This is a modern, optimized version of Intel's 14 nm technology, designed for mobile efficiency.

The i5-4590S uses the older Haswell architecture, also known by the codename Haswell, on a 22 nm process node. It belongs to the Core i5 (Haswell) generation and was released in 2014. The 22 nm node is an older generation, which means the i5-4590S has a larger transistor size and likely lower power efficiency per clock.

The transistor counts and die sizes reflect this difference. The i5-4590S has 1,400 million transistors on a 177 mm² die, while the i7-8665U's pack does not list these figures. The newer 14 nm process allows the i7-8665U to pack more functionality into a lower power envelope, as evidenced by its 15 W TDP versus the i5-4590S's 65 W TDP.

Cache differences are also notable. Both have 64 KB L1 and 256 KB L2 per core, but the i7-8665U has 8 MB of shared L3 cache, while the i5-4590S has only 6 MB. This larger L3 cache helps the i7-8665U in latency-sensitive workloads.

The i7-8665U supports both DDR3 and DDR4 memory with a dual-channel bus and a memory bandwidth of 38.4 GB/s. The i5-4590S only supports DDR3, also dual-channel, but its memory bandwidth is not listed in the data. The i7 also uses Intel BGA 1528 socket, while the i5 uses Intel Socket 1150.

Specification Differences

The core count is identical at 4 cores, but the thread counts diverge: the i7-8665U has 8 threads, while the i5-4590S has 4. This is the most significant specification difference, as Hyper-Threading on the i7 effectively doubles its logical processing capacity.

Clock speeds tell a story of trade-offs. The i5-4590S has a base clock of 2.90 GHz, which is higher than the i7-8665U's 1.90 GHz base clock. However, the i7-8665U's boost clock of 4.80 GHz dramatically exceeds the i5-4590S's 3.60 GHz boost, giving the mobile chip a much higher ceiling for single-threaded and lightly-threaded workloads.

The TDP difference is stark: 15 W for the i7-8665U versus 65 W for the i5-4590S. This makes the i7-8665U far more power-efficient, but it also means the i5-4590S requires more robust cooling. The i5's process node is 22 nm, while the i7 uses 14 nm, explaining part of the efficiency gap.

Memory support differs, with the i7-8665U supporting both DDR3 and DDR4, while the i5-4590S is limited to DDR3. The i7-8665U has a listed memory bandwidth of 38.4 GB/s, while the i5-4590S's bandwidth is not provided. Both support dual-channel memory and neither supports ECC memory.

Integrated graphics are different generations: the i7-8665U has UHD Graphics 620, while the i5-4590S has Intel HD 4600. The i7-8665U's socket is Intel BGA 1528, indicating a soldered mobile design, while the i5-4590S uses Intel Socket 1150 for socketed desktop installation. The i7-8665U has a launch MSRP of $409, while the i5-4590S has no launch MSRP listed.

Head-to-Head Benchmarks

The Cinebench R15 multi-core test shows the i7-8665U scoring 527 against the i5-4590S's 437, a 20.6% delta. This is the first of several identical 20.6% margins, indicating a consistent performance ratio across different Cinebench versions.

In Cinebench R15 single-core, the i7-8665U scores 74, which is 21.3% higher than the i5-4590S's 61. This is the largest single-core margin in the entire comparison, highlighting the i7's superior boost clock and architectural efficiency.

Moving to Cinebench R20, the multi-core test shows the i7-8665U at 2197 versus 1821 for the i5-4590S, again a 20.6% difference. The single-core R20 test shows a score of 309 for the i7-8665U and 257 for the i5-4590S, a 20.2% lead. This is the smallest margin in the comparison, but it still represents a clear win for the i7.

The Cinebench R23 multi-core test continues the trend: the i7-8665U scores 5232, and the i5-4590S scores 4338, a 20.6% delta. The R23 single-core test shows 738 versus 612, also a 20.6% delta.

Notably, the i5-4590S has additional Geekbench scores in its pack: a multi-core score of 3289 and a single-core score of 1126. The i7-8665U does not have Geekbench scores listed, so a direct comparison is not possible from the data.

The pattern is clear: the i7-8665U maintains a roughly 20-21% performance advantage across all Cinebench tests. This consistency suggests that the difference is not workload-specific but rather a fundamental architectural and specification advantage. The i7's 8 threads and higher boost clock are the primary drivers, allowing it to outperform the i5-4590S despite having a much lower base clock and TDP. For any user choosing between these two, the data overwhelmingly favors the i7-8665U in terms of raw compute performance, with the i5-4590S's only advantage being its desktop platform and socket compatibility.