Intel Core i7-8665UE vs Intel Xeon D-1520 Comparison

Head-to-Head Benchmarks

The recorded data presents a remarkably consistent picture: the Intel Xeon D-1520 wins every single benchmark in the head-to-head comparison against the Intel Core i7-8665UE. Across six Cinebench tests, the Xeon D-1520 edges ahead in each instance, though the margins are uniformly narrow. The largest delta appears in the Cinebench R15 single-core test, where the Xeon D-1520 scores 59 against the Core i7-8665UE's 58, a 1.7% advantage. The smallest gap is in Cinebench R20 multi-core, with the Xeon D-1520 at 1755 versus 1732, a 1.3% lead.

The multi-core results follow a predictable pattern. In Cinebench R15 multi-core, the Xeon D-1520 posts 421 while the Core i7-8665UE manages 415, a 1.4% difference. Cinebench R20 multi-core shows 1755 against 1732 (1.3%), and Cinebench R23 multi-core records 4179 versus 4124 (1.3%). These are not dramatic victories; they are consistent, small advantages that repeat across every workload iteration.

Single-core performance tells the same story. Cinebench R15 single-core gives the Xeon D-1520 a 59 to 58 win (1.7%). Cinebench R20 single-core shows 247 to 244 (1.2%). Cinebench R23 single-core delivers 590 to 582 (1.4%). The Xeon D-1520 maintains its lead in every single-core test, but the differences hover around one to two percent, suggesting the two processors are fundamentally similar in raw per-thread capability.

What makes this interesting is the underlying configuration. Both chips have 4 cores and 8 threads, so the head-to-head is a pure test of clock behavior, cache design, and architectural efficiency. The Xeon D-1520's base clock is listed as 2.20 GHz, while the Core i7-8665UE's base clock is listed as 1700.00 MHz (the database records it in that format). Yet the Core i7-8665UE boosts much higher at 4.40 GHz versus 2.60 GHz for the Xeon D-1520. Despite that large boost deficit, the Xeon D-1520 still wins every benchmark. The data implies that sustained multi-core throughput favors the Xeon's design, while the Core i7's higher boost clock does not translate into a single-core victory.

Where Each One Wins

The win tally is one-sided: the Intel Xeon D-1520 takes all six head-to-head benchmarks, while the Intel Core i7-8665UE records zero wins. This does not mean the Core i7-8665UE is without merit; it means the benchmark data, as recorded, shows no test where the mobile chip outperforms the server chip.

For the Xeon D-1520, its wins span both single-core and multi-core workloads. The largest margin (1.7%) comes in Cinebench R15 single-core, which is notable because the Core i7-8665UE has a substantially higher boost clock (4.40 GHz versus 2.60 GHz). The Xeon's 2.20 GHz base clock and 2.60 GHz boost clock are both lower, yet it still manages to lead in single-threaded Cinebench R15. This suggests the Xeon D-1520's Broadwell architecture, with its larger per-core L3 cache allocation (1.5 MB per core), may be more efficient per clock in this particular test.

The multi-core wins are consistent but modest. In Cinebench R15, R20, and R23 multi-core tests, the Xeon D-1520 leads by 1.3% to 1.4%. These are tight margins, and the data does not indicate a decisive multi-core advantage. The Core i7-8665UE, despite its lower TDP (15 watts versus 45 watts) and mobile-oriented Whiskey Lake architecture, nearly matches the Xeon D-1520 in raw throughput. The practical difference between a 421 and a 415 score in Cinebench R15 multi-core is negligible in real-world terms.

The Core i7-8665UE's strengths do not appear in the benchmark wins, but they exist elsewhere in the database. Its integrated UHD Graphics 620 provides a graphics solution that the Xeon D-1520 lacks entirely, since the Xeon has no integrated graphics listed. The Core i7 also supports a higher memory bandwidth at 38.4 GB/s, while the Xeon's memory bandwidth is not recorded. These are qualitative advantages that the benchmark scores do not capture.

FAQ

Q: Which processor wins more benchmarks in the head-to-head comparison?

A: The Intel Xeon D-1520 wins all six head-to-head benchmarks. The Intel Core i7-8665UE wins zero. The Xeon's margins range from 1.2% to 1.7%.

Q: How close are the multi-core scores between the two?

A: Very close. In Cinebench R23 multi-core, the Xeon D-1520 scores 4179 against the Core i7-8665UE's 4124, a 1.3% difference. In Cinebench R20 multi-core, the scores are 1755 and 1732, also a 1.3% gap.

Q: Does the Core i7-8665UE's higher boost clock help it win any single-core test?

A: No. Despite a boost clock of 4.40 GHz versus the Xeon D-1520's 2.60 GHz, the Core i7-8665UE loses every single-core test. The largest single-core margin is in Cinebench R15, where the Xeon wins 59 to 58 (1.7%).

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

A: Both the Intel Xeon D-1520 and the Intel Core i7-8665UE have 4 cores and 8 threads. This makes the head-to-head comparison a direct test of other architectural factors.

Q: Which processor has ECC memory support?

A: The Intel Xeon D-1520 supports ECC memory. The Intel Core i7-8665UE does not list ECC memory support in the recorded data.

Q: How do their average benchmark scores compare?

A: The Xeon D-1520 has an average benchmark score of 1209, while the Core i7-8665UE averages 1193. The Xeon also sits at the 34th percentile of all CPUs, slightly above the Core i7's 33rd percentile.

Specification Differences

The two processors diverge on several key specification points. The Intel Xeon D-1520 uses the Intel BGA 1667 socket, while the Intel Core i7-8665UE uses Intel BGA 1528. They are not socket-compatible. The Xeon D-1520 has a TDP of 45 watts, three times the Core i7-8665UE's 15 watts. This reflects their intended market segments: Server/Workstation for the Xeon, Mobile for the Core i7.

Clock speeds differ significantly. The Xeon D-1520 has a base clock of 2.20 GHz and a boost clock of 2.60 GHz. The Core i7-8665UE's base clock is recorded as 1700.00 MHz (likely a formatting artifact, but the database records it as such) and its boost clock reaches 4.40 GHz. The Core i7 has a much higher boost ceiling, yet it still loses every benchmark.

Memory support is identical in type (DDR3, DDR4) and bus width (dual-channel), but the Core i7-8665UE lists a memory bandwidth of 38.4 GB/s, while the Xeon D-1520's memory bandwidth is not recorded. ECC memory support is present only on the Xeon D-1520. PCIe lane counts differ: the Xeon D-1520 provides Gen 3 with 24 lanes (CPU only), while the Core i7-8665UE provides Gen 3 with 16 lanes (CPU only).

Integrated graphics are a major differentiator. The Core i7-8665UE includes UHD Graphics 620, while the Xeon D-1520 has no integrated graphics listed. The Xeon D-1520's release date is recorded as 2015-03-08, while the Core i7-8665UE's is 2018-09-30. The Xeon D-1520 remains in Active production status, whereas the Core i7-8665UE is listed as End-of-life. The launch MSRP for the Xeon D-1520 is $199, and for the Core i7-8665UE it is $409.

Architecture Differences

The architectural split is clear: the Intel Xeon D-1520 is built on Broadwell, specifically the Broadwell-DE generation, while the Intel Core i7-8665UE uses Whiskey Lake, designated Whiskey Lake-U. Both are manufactured on Intel's 14 nm process node at Intel's foundry, so the process technology is identical. The Xeon D-1520 is a server-class design, while the Core i7-8665UE is a mobile-class design.

Cache layouts differ notably. The Xeon D-1520 has an L1 cache of 64 KB per core, an L2 cache of 256 KB per core, and an L3 cache of 1.5 MB per core. The Core i7-8665UE also has 64 KB of L1 per core and 256 KB of L2 per core, but its L3 cache is 8 MB shared across all cores. This is a fundamental difference: per-core L3 versus shared L3. The Xeon's per-core allocation totals 6 MB across four cores, while the Core i7 offers 8 MB shared, which is a larger total pool but distributed differently.

The Xeon D-1520's transistor count is recorded at 3,200 million with a die size of 246 mm². The Core i7-8665UE's transistor count and die size are not recorded in the database. This absence makes a direct comparison of physical implementation impossible, but the Broadwell-DE design is clearly larger and more server-oriented.

The Core i7-8665UE's Whiskey Lake architecture is a refined version of Intel's 14 nm process, optimized for low power and mobile efficiency. Its 15-watt TDP and integrated UHD Graphics 620 indicate a design focused on compact laptops and embedded mobile use. The Xeon D-1520, with its 45-watt TDP and no integrated graphics, targets server racks and workstation environments where discrete graphics are assumed and ECC memory is valued.

The Verdict

The data points to a clear, if narrow, winner: the Intel Xeon D-1520 outperforms the Intel Core i7-8665UE in every recorded benchmark. The margins are small, ranging from 1.2% to 1.7%, but they are consistent across six tests. The Xeon D-1520 also holds a higher average benchmark score (1209 versus 1193) and a slightly better percentile ranking (34th versus 33rd among all CPUs).

Who should pick the Xeon D-1520? Anyone prioritizing server or workstation workloads where ECC memory support is required, where the 24 PCIe Gen 3 lanes provide more expansion headroom, and where a 45-watt TDP is acceptable. The Xeon's Active production status also means it remains available for ongoing system designs. Its launch MSRP of $199 is recorded in the database, and its benchmark lead, though small, is real.

Who should pick the Core i7-8665UE? The data shows it loses every benchmark, but it offers integrated UHD Graphics 620, which the Xeon D-1520 lacks entirely. Its 15-watt TDP makes it suitable for mobile or low-power embedded designs. Its higher boost clock of 4.40 GHz does not translate into benchmark wins, but the Whiskey Lake architecture includes integrated graphics and a shared 8 MB L3 cache. The Core i7-8665UE is end-of-life, which may matter for long-term supply planning, and its launch MSRP is $409.

For raw performance, the Xeon D-1520 is the better choice according to the recorded data. For systems requiring integrated graphics or minimal power draw, the Core i7-8665UE has qualitative advantages that benchmarks do not measure. The performance gap is too small to be decisive in most real-world scenarios, so the choice ultimately rests on platform requirements: ECC memory, PCIe lanes, and production status favor the Xeon; integrated graphics and low TDP favor the Core i7.