Intel Core i5-8279U vs Intel Core i7-3930K Comparison

FAQ

Q: Which processor has more cores and threads?

A: The Intel Core i7-3930K has 6 cores and 12 threads, while the Intel Core i5-8279U has 4 cores and 8 threads.

Q: Which CPU is newer?

A: The Intel Core i5-8279U was released on 2019-04-02, while the Intel Core i7-3930K was released on 2011-11-13.

Q: Which processor has a higher boost clock?

A: The Intel Core i5-8279U has a boost clock of 4.10 GHz, compared to 3.80 GHz for the Intel Core i7-3930K.

Q: Which CPU wins in Geekbench multicore performance?

A: The Intel Core i5-8279U wins the Geekbench multicore test with a score of 3764, which is 25.8% ahead of the Intel Core i7-3930K's 2991.

Q: Which CPU supports DDR4 memory?

A: The Intel Core i5-8279U supports DDR4 memory, while the Intel Core i7-3930K supports DDR3.

Q: Which processor has a larger L3 cache?

A: The Intel Core i7-3930K has 12 MB of shared L3 cache, double the 6 MB shared L3 cache of the Intel Core i5-8279U.

Architecture Differences

The two processors come from different eras and design philosophies. The Intel Core i5-8279U is built on Coffee Lake-U, a 14 nm architecture, while the Intel Core i7-3930K uses Sandy Bridge-E on a 32 nm process. The process node difference is significant: the i5-8279U packs 2,300 million transistors into a 126 mm² die, whereas the i7-3930K holds 2,270 million transistors in a much larger 435 mm² die. The newer node allows the mobile chip to deliver comparable or better performance in certain workloads while drawing far less power.

The core configurations diverge sharply. The i7-3930K offers 6 cores and 12 threads, giving it a raw thread-count advantage over the i5-8279U's 4 cores and 8 threads. However, the i5-8279U compensates with a higher boost clock of 4.10 GHz versus 3.80 GHz on the i7-3930K, and a base clock of 2.40 GHz versus 3.20 GHz. The i7-3930K's higher base clock helps it in sustained workloads, but the i5-8279U's boost capability gives it an edge in bursty, single-threaded tasks.

Cache hierarchies also differ. Both chips use 64 KB L1 and 256 KB L2 per core, but the i7-3930K has 12 MB of shared L3 cache, double the 6 MB on the i5-8279U. The extra L3 cache benefits the older desktop part in multi-threaded scenarios where larger working sets fit on-chip.

Memory architecture is another major split. The i5-8279U uses dual-channel DDR4 with 34.1 GB/s bandwidth, while the i7-3930K uses quad-channel DDR3 with 51.2 GB/s bandwidth. Despite the older memory type, the quad-channel configuration gives the i7-3930K substantially more memory bandwidth. PCIe connectivity also favors the desktop chip: the i7-3930K provides Gen 3 with 40 lanes, versus Gen 3 with 16 lanes on the i5-8279U.

Integrated graphics separate the two as well. The i5-8279U includes Iris Pro Plus 655 graphics, while the i7-3930K has no integrated graphics, requiring a discrete GPU. The i5-8279U is a mobile part on Intel BGA 1526, while the i7-3930K is a desktop chip on Intel Socket 2011. The i7-3930K has an unlocked multiplier; the i5-8279U does not.

Where Each One Wins

The Intel Core i7-3930K wins every Cinebench test in the head-to-head comparison. Across Cinebench R15, R20, and R23, both multicore and singlecore, the i7-3930K consistently outperforms the i5-8279U by roughly 9.2% to 9.7%. The largest margin is in Cinebench R20 singlecore, where the i7-3930K leads by 9.7%. This suggests the older desktop chip has an advantage in rendering workloads that stress sustained multi-threaded execution, likely due to its 6-core/12-thread configuration and higher base clock.

The Intel Core i5-8279U dominates Geekbench. It wins Geekbench multicore by 25.8% and Geekbench singlecore by a massive 95.9%. The singlecore margin is especially striking: 1209 versus 617. This indicates the mobile chip has superior per-core efficiency, a hallmark of the newer Coffee Lake architecture. The i5-8279U is the better choice for workloads that rely on single-threaded responsiveness and modern instruction efficiency, such as everyday desktop tasks, lightweight productivity, and applications optimized for newer CPUs.

For users prioritizing multi-threaded rendering in Cinebench, the i7-3930K is the stronger option. For users who need strong single-core performance and modern platform features, the i5-8279U wins decisively. The two chips split wins evenly in the head-to-head tests: the i7-3930K takes 6 wins, the i5-8279U takes 2.

Specification Differences

The following specifications differ between the two processors:

• Cores: 4 (i5-8279U) vs 6 (i7-3930K)
• Threads: 8 (i5-8279U) vs 12 (i7-3930K)
• Base clock: 2.40 GHz (i5-8279U) vs 3.20 GHz (i7-3930K)
• Boost clock: 4.10 GHz (i5-8279U) vs 3.80 GHz (i7-3930K)
• TDP: 28 W (i5-8279U) vs 130 W (i7-3930K)
• Socket: Intel BGA 1526 (i5-8279U) vs Intel Socket 2011 (i7-3930K)
• Architecture: Coffee Lake (i5-8279U) vs Sandy Bridge (i7-3930K)
• Process node: 14 nm (i5-8279U) vs 32 nm (i7-3930K)
• Transistors: 2,300 million (i5-8279U) vs 2,270 million (i7-3930K)
• Die size: 126 mm² (i5-8279U) vs 435 mm² (i7-3930K)
• L3 cache: 6 MB shared (i5-8279U) vs 12 MB shared (i7-3930K)
• Memory support: DDR4 (i5-8279U) vs DDR3 (i7-3930K)
• Memory bus: Dual-channel (i5-8279U) vs Quad-channel (i7-3930K)
• Memory bandwidth: 34.1 GB/s (i5-8279U) vs 51.2 GB/s (i7-3930K)
• PCIe: Gen 3, 16 lanes (i5-8279U) vs Gen 3, 40 lanes (i7-3930K)
• Integrated graphics: Iris Pro Plus 655 (i5-8279U) vs None (i7-3930K)
• Market segment: Mobile (i5-8279U) vs Desktop (i7-3930K)
• Release date: 2019-04-02 (i5-8279U) vs 2011-11-13 (i7-3930K)
• Multiplier unlocked: No (i5-8279U) vs Yes (i7-3930K)

Head-to-Head Benchmarks

The head-to-head data shows a clear split between Cinebench and Geekbench results. The Intel Core i7-3930K wins all six Cinebench tests. In Cinebench R15 multicore, the i7-3930K scores 701 against 634 for the i5-8279U, a 9.6% advantage. In Cinebench R15 singlecore, the i7-3930K scores 98 against 89, a 9.2% lead. The pattern continues in Cinebench R20: multicore 2921 versus 2643, a 9.5% gap, and singlecore 412 versus 372, a 9.7% gap. Cinebench R23 shows the same story: multicore 6955 versus 6294, a 9.5% lead, and singlecore 981 versus 888, also a 9.5% lead. The consistency of these margins suggests the i7-3930K's extra cores and higher base clock deliver a stable advantage in Cinebench's rendering workloads.

The Intel Core i5-8279U flips the script in Geekbench. In Geekbench multicore, it scores 3764 versus 2991 for the i7-3930K, a 25.8% victory. The singlecore result is even more one-sided: 1209 versus 617, a 95.9% lead. The i5-8279U nearly doubles the i7-3930K's singlecore score, a dramatic demonstration of how far per-core performance has advanced since Sandy Bridge. The i5-8279U's higher boost clock of 4.10 GHz and modern Coffee Lake architecture clearly pay off in Geekbench's workload mix.

Average benchmark scores place both chips close together overall. The i5-8279U has an average benchmark score of 1987, while the i7-3930K averages 1960, a difference of only 1.4% favoring the i5-8279U. Both sit at the 44th percentile among all CPUs in the database. The i5-8279U's nearest rivals include the AMD Ryzen Embedded V1756B (1986, 0.1% behind), the Intel Xeon E3-1585L v5 (1989, 0.1% ahead), the Intel Xeon E3-1285L v4 (1991, 0.2% ahead), and the AMD Ryzen 5 1500X (1992, 0.2% ahead). The i7-3930K's nearest rivals include the Intel Xeon D-2712T (1964, 0.2% ahead), the AMD Ryzen 5 PRO 3400GE (1954, 0.3% behind), the AMD Ryzen 5 2600H (1967, 0.3% ahead), and the AMD Ryzen 3 2300X (1968, 0.4% ahead). The rival clusters reinforce the conclusion: the two chips perform at about the same overall level, with strengths in different benchmark families.

The Verdict

The Intel Core i7-3930K is the pick for users who need consistent multi-threaded rendering performance in Cinebench. It wins all six Cinebench tests with margins between 9.2% and 9.7%, and it offers 6 cores, 12 threads, 12 MB of L3 cache, and quad-channel DDR3 with 51.2 GB/s of bandwidth. It also provides 40 PCIe lanes and an unlocked multiplier, making it the more expandable and overclockable platform. Its 130 W TDP and lack of integrated graphics mean it belongs in a desktop system with a discrete GPU.

The Intel Core i5-8279U is the choice for users who value modern per-core efficiency and single-threaded performance. It wins Geekbench multicore by 25.8% and Geekbench singlecore by 95.9%, demonstrating superior per-core architecture and IPC gains from the 14 nm Coffee Lake design. It also brings DDR4 support, Iris Pro Plus 655 integrated graphics, a 28 W TDP, and a mobile form factor, making it a suitable option for compact laptops or all-in-one systems where space and power constraints matter.

The recorded data shows a 1.4% overall performance parity between the two chips, with the i5-8279U averaging 1987 and the i7-3930K averaging 1960. That means platform choice should depend on workload: Cinebench favors the i7-3930K across the board, while Geekbench heavily favors the i5-8279U. The i7-3930K's launch MSRP was $583, reflecting its high-end desktop positioning at release. The i5-8279U launched with a $320 MSRP.

Users coming from an older desktop system with a Sandy Bridge-E platform will find the i7-3930K a familiar and capable six-core workstation processor. Users seeking a newer mobile chip with modern DMA and single-thread speed will gravitate to the i5-8279U. The i7-3930K remains a valid choice for multi-core rendering, and the i5-8279U is the better all-around modern processor for everyday responsiveness. Both are end-of-life parts, so the decision rests on which benchmark family matches the intended workload.