Intel Core i5-9600K vs Intel Xeon 6756E Comparison

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Core i5-9600K has an average benchmark score of 14605, while the Intel Xeon 6756E scores 14163. That places the i5-9600K at the 69th percentile of all CPUs and the Xeon 6756E at the 68th percentile.

Q: How do these two compare to their nearest rivals?

A: The i5-9600K is 0.1% ahead of the AMD Ryzen 5 5500U and 0.2% ahead of both the AMD EPYC 7473X and Intel Xeon 6315P. The Xeon 6756E is 0.2% behind the Intel Core i5-10400F and 0.3% ahead of the AMD EPYC 7552.

Q: Which processor wins more head-to-head benchmark tests?

A: The Xeon 6756E wins 11 of the 17 recorded head-to-head tests, while the i5-9600K wins 6. However, the i5-9600K's wins are often by much larger margins.

Q: What is the largest single benchmark margin between the two?

A: The largest margin is in PassMark extended instructions, where the i5-9600K leads by 95.8%. The largest Xeon win is in PassMark data encryption, where it leads by 61.1%.

Q: Do both processors support ECC memory?

A: No. The Xeon 6756E supports ECC memory, while the i5-9600K does not.

Q: Are both processors currently in production?

A: No. The i5-9600K is end-of-life, while the Xeon 6756E is listed as active production.

Architecture Differences

The Intel Core i5-9600K and Intel Xeon 6756E come from fundamentally different design philosophies. The i5-9600K is a 6-core, 6-thread desktop processor built on Coffee Lake architecture, produced on Intel's 14 nm process. The Xeon 6756E is a 128-core, 128-thread server processor using Sierra Forest architecture on a 5 nm process, explicitly engineered for density and efficiency in scale-out workloads.

The physical package tells the story. The Xeon 6756E has a die size of 578 mm², while the i5-9600K's die size is not recorded in the database. The Xeon uses Intel Socket 4710, the i5-9600K uses Intel Socket 1151. The i5-9600K has an unlocked multiplier, making it overclockable, while the Xeon 6756E is locked.

Cache hierarchies differ substantially. The i5-9600K has 64 KB of L1 cache per core, 256 KB of L2 per core, and 9 MB of shared L3. The Xeon 6756E has 96 KB of L1 per core, 4 MB of L2 per module, and 96 MB of shared L3. The Xeon's L3 cache is more than ten times larger and its L2 allocation per module is far more generous.

Memory architecture is another major split. The i5-9600K supports DDR4 over a dual-channel bus with 42.7 GB/s of memory bandwidth. The Xeon 6756E supports DDR5 over an eight-channel bus with 409.6 GB/s of memory bandwidth, roughly 9.6 times the bandwidth. The Xeon also supports ECC memory, which the i5-9600K lacks.

PCIe connectivity is dramatically different. The i5-9600K provides PCIe Gen 3 with 16 lanes from the CPU. The Xeon 6756E provides PCIe Gen 5 with 88 lanes from the CPU. That is a generation leap and a 5.5 times increase in lane count.

The i5-9600K includes integrated UHD 630 graphics; the Xeon 6756E has no integrated graphics. Clock speeds run in opposite directions: the i5-9600K has a base clock of 3.70 GHz and a boost clock of 4.60 GHz, while the Xeon 6756E has a base of 1.80 GHz and a boost of 2.60 GHz. The i5-9600K's TDP is 95 W, the Xeon 6756E's is 225 W. The i5-9600K launched on 2018-10-18 and is end-of-life; the Xeon 6756E launched on 2024-06-02 and remains active. The Xeon 6756E carries a launch MSRP of $8428.

The Verdict

The benchmark data does not support a single universal winner. Instead, it describes two processors built for different jobs, each excelling where the other cannot follow.

For single-threaded and latency-sensitive desktop workloads, the i5-9600K is the clear choice. It beats the Xeon 6756E by 65.7% in PassMark single-thread performance, and its higher clock speeds of 4.60 GHz boost versus 2.60 GHz boost give it a decisive edge in workloads that depend on per-core speed. The i5-9600K also wins the extended instructions test by 95.8%, a massive margin that points to superior per-core instruction throughput in that benchmark.

For server-oriented, parallel, and memory-heavy duties, the Xeon 6756E is the obvious pick. It wins the multithread benchmark by 7.1%, the physics test by 49%, data encryption by 61.1%, and prime number finding by 67.7%. Its 128 cores, 96 MB of L3, eight-channel DDR5, and 88 PCIe Gen 5 lanes make it a platform designed for throughput at scale, not for responsiveness in a single application window.

The i5-9600K is the right processor for a desktop system where per-core speed, overclocking headroom, and integrated graphics matter. The Xeon 6756E is the right processor for a server or workstation where core count, memory bandwidth, ECC support, and PCIe expansion dominate. Pick the i5-9600K if the workload is interactive or single-threaded. Pick the Xeon 6756E if the workload is parallel, memory-bound, or requires maximum core density.

Specification Differences

The two processors differ in nearly every major specification field.

• Cores: i5-9600K has 6 cores; Xeon 6756E has 128 cores.
• Threads: i5-9600K has 6 threads; Xeon 6756E has 128 threads.
• Base clock: 3.70 GHz versus 1.80 GHz.
• Boost clock: 4.60 GHz versus 2.60 GHz.
• TDP: 95 W versus 225 W.
• Socket: Intel Socket 1151 versus Intel Socket 4710.
• Architecture: Coffee Lake versus Sierra Forest.
• Process node: 14 nm versus 5 nm.
• Die size: not recorded versus 578 mm².
• L1 cache: 64 KB per core versus 96 KB per core.
• L2 cache: 256 KB per core versus 4 MB per module.
• L3 cache: 9 MB shared versus 96 MB shared.
• Memory support: DDR4 versus DDR5.
• Memory bus: Dual-channel versus Eight-channel.
• Memory bandwidth: 42.7 GB/s versus 409.6 GB/s.
• ECC memory: false versus true.
• PCIe: Gen 3, 16 lanes versus Gen 5, 88 lanes.
• Integrated graphics: UHD 630 versus N/A.
• Market segment: Desktop versus Server/Workstation.
• Production status: End-of-life versus Active.
• Release date: 2018-10-18 versus 2024-06-02.
• Multiplier unlocked: true versus false.
• Part number: SR3WZ versus SRPFX.

Head-to-Head Benchmarks

The Xeon 6756E takes the Cinebench suite outright. In Cinebench R15 multicore, it scores 980 against the i5-9600K's 912, a 6.9% lead. In R15 single-core, it scores 138 against 128, a 7.2% lead. R20 multicore shows 4085 versus 3803, again 6.9% ahead. R20 single-core is 576 versus 536, 6.9% ahead. R23 multicore is 9728 versus 9055, 6.9% ahead. R23 single-core is 1373 versus 1278, 6.9% ahead. The consistency across every Cinebench iteration is notable: the Xeon leads by roughly 7% in both single and multi-core variants.

The PassMark suite tells a more varied story. The i5-9600K wins PassMark single-thread by 65.7%, scoring 2727 against 1646. It also wins extended instructions by 95.8%, scoring 12914 against 6596. In floating-point math, the i5-9600K leads 24913 to 22451, an 11% advantage. Data compression goes to the i5-9600K at 148639 versus 123443, a 20.4% margin. Random string sorting also favors the i5-9600K, 18313 to 15847, a 15.6% win.

The Xeon 6756E dominates the remaining PassMark tests. Data encryption is a blowout: 8409 versus 3269, a 61.1% lead for the Xeon. Find prime numbers goes 133 to 43, a 67.7% margin. Physics goes 1463 to 746, a 49% difference. Integer math is closer, 30806 to 29215, a 5.2% Xeon win. The multithread test goes to the Xeon 11445 to 10636, a 7.1% margin.

The overall pattern is clear. The Xeon wins the majority of tests, but its margins are modest in most cases. The i5-9600K wins fewer tests but often by large margins, especially in single-thread and extended instruction workloads.

Where Each One Wins

The i5-9600K wins in scenarios that reward high clock speeds and per-core efficiency. Its 65.7% single-thread advantage makes it better for applications that cannot use many cores, such as lightly threaded desktop software, legacy applications, and interactive workloads. Its 95.8% lead in extended instructions suggests a strong advantage in workloads that rely on advanced per-core instruction execution. The 20.4% data compression win and 15.6% random string sorting win indicate that certain data processing tasks actually run faster on the smaller, higher-clocked desktop chip. The 11% floating-point math win reinforces this: for floating-point-heavy but single-threaded or lightly threaded tasks, the i5-9600K is the better choice. Its integrated UHD 630 graphics, unlocked multiplier, and lower 95 W TDP also make it suitable for a desktop system where overclocking and integrated display output are desired.

The Xeon 6756E wins in scenarios that demand massive parallelism and memory throughput. Its 128 cores and 128 threads dominate heavily multithreaded workloads. The 49% physics win and 61.1% data encryption win point to workloads that scale across cores, such as scientific simulation, cryptographic processing, and batch data processing. The 67.7% prime number finding win indicates a strong advantage in integer-heavy parallel computation. The 7.1% multithread win and 5.2% integer math win, while modest, still favor the Xeon in sustained parallel execution. Its eight-channel DDR5 memory architecture with 409.6 GB/s bandwidth, 96 MB shared L3, ECC support, and 88 PCIe Gen 5 lanes make it the appropriate choice for server and workstation deployments where memory capacity, memory bandwidth, and expansion are critical. The Xeon's 225 W TDP and locked multiplier are acceptable trade-offs in a server context where density and reliability matter more than per-core speed.