Intel Xeon D-1520 vs Intel Xeon D-1527 Comparison

The Intel Xeon D-1520 and Intel Xeon D-1527 are nearly identical twins in Intel’s Broadwell-DE server lineup, separated by a razor-thin performance margin that will rarely dictate a purchasing decision. Both are 4-core, 8-thread parts on the same 14 nm process, but the D-1520 edges out the D-1527 in every single benchmark recorded, while the D-1527 counters with a lower thermal envelope. The data shows a head-to-head contest where the D-1520 wins all six benchmark comparisons, yet the D-1527 remains a compelling alternative for power-constrained deployments.

Head-to-Head Benchmarks

The benchmark results are remarkably close, with the D-1520 winning every comparison by less than a quarter of a percentage point. In Cinebench R15 multi-core, the D-1520 scores 421 against the D-1527’s 420, a delta of just 0.2%. That pattern repeats across the entire suite. In Cinebench R20 multi-core, the D-1520 posts 1755 versus 1753, a 0.1% lead. The R23 multi-core test shows 4179 for the D-1520 and 4176 for the D-1527, again a 0.1% margin. The single-core results are even tighter: both chips score exactly 59 in R15 single-core and exactly 247 in R20 single-core, resulting in a 0.0% delta. In R23 single-core, the D-1520 scores 590 against 589 for the D-1527, a 0.2% advantage.

The aggregate benchmark average tells the same story. The D-1520 holds an average benchmark score of 1209, while the D-1527 sits at 1207. That 0.1% difference places the D-1520 marginally ahead in the overall standings, but both chips occupy the same 34th percentile among all CPUs. When compared against common rivals, the two Xeons effectively trade places. The nearest rival to the D-1520 is the Intel Core i3-8121U, which matches its 1209 average score with a 0.0% delta. The D-1527 trails its sibling by 0.1% but also sits behind the Xeon E5645 and Core i3-7300T, both of which average 1211, representing a -0.3% delta for the D-1527.

The largest single victory for the D-1520 comes in R15 multi-core, where its 0.2% lead is the widest margin recorded. The R23 single-core test also shows a 0.2% gap, while the remaining multi-core tests settle at 0.1%. The single-core tests at R15 and R20 are dead even. The data suggests that the D-1520’s slight boost clock advantage — 2.60 GHz versus 2.70 GHz for the D-1527 — does not translate into a meaningful performance gap, as the D-1520 still wins despite the lower peak frequency. This counterintuitive result reinforces how close these silicon bins are.

Where Each One Wins

The D-1520 wins outright in every benchmark category, making it the default choice for raw performance. Its 421 R15 multi-core score and 4179 R23 multi-core score represent the highest recorded figures in this comparison. For workloads that stress all cores — such as database transactions, virtualization hosts, or compilation tasks — the D-1520’s multi-core results, even if only 0.1% to 0.2% ahead, are the best available in this pairing. The single-core wins are equally consistent, with 590 in R23 single-core being the top mark.

The D-1527, despite losing all six benchmark comparisons, wins in a different metric: thermal design power. The D-1527 carries a 35 W TDP, while the D-1520 is rated at 45 W. That 10 W difference is the largest distinction between the two parts. For dense server chassis with limited cooling or power budgets, the D-1527’s lower TDP allows for more efficient operation without a meaningful performance penalty — the average score delta is just 0.1%. The D-1527 also launches with a higher MSRP of $213, compared to the D-1520’s $199, though pricing is not a factor in performance analysis.

In single-core workloads, the two chips are functionally identical. The R15 and R20 single-core scores are exactly equal at 59 and 247, respectively. The R23 single-core test shows a 1-point difference, which is within measurement noise. For lightly threaded applications like web serving or control-plane tasks, users will see no practical difference. The D-1527’s advantage is purely operational: it delivers nearly the same performance at a lower thermal envelope, which can be decisive in fanless or passively cooled designs.

Architecture Differences

Both processors share the same Broadwell architecture, built on Intel’s 14 nm process at the company’s own foundry. Each chip integrates 3,200 million transistors on a 246 mm² die. The core configuration is identical: 4 cores and 8 threads, with a per-core cache hierarchy of 64 KB L1, 256 KB L2, and 1.5 MB L3. The memory subsystem supports both DDR3 and DDR4 in a dual-channel configuration, with ECC memory enabled for server reliability. Both parts use the Intel BGA 1667 socket and provide 24 PCIe Gen 3 lanes from the CPU.

The only clock-speed difference is in the boost frequency. The D-1520 runs at a 2.20 GHz base clock with a 2.60 GHz boost, while the D-1527 matches the 2.20 GHz base but boosts to 2.70 GHz. Despite the higher boost on the D-1527, the D-1520 posts better benchmark scores, suggesting that sustained multi-core operation favors the D-1520’s power allocation. The TDP difference is notable: the D-1520 draws 45 W, while the D-1527 is rated at 35 W, a 22% reduction in thermal envelope for the D-1527.

Both chips are unlocked multipliers? No — neither has an unlocked multiplier, so overclocking is not an option. The production status for both is Active, and they belong to the same Xeon D (Broadwell-DE) generation. The release dates differ slightly: the D-1520 launched on March 8, 2015, while the D-1527 followed on October 31, 2015. The part numbers are SR29B for the D-1520 and SR2DK for the D-1527, confirming distinct silicon revisions. Neither chip includes integrated graphics, which is typical for server-focused parts.

The memory bandwidth is not specified in the data, but the dual-channel DDR3/DDR4 support with ECC is identical. The PCIe configuration is also the same: Gen 3 with 24 lanes from the CPU. For architectural purposes, these are the same silicon die with different power and clock bins. The 14 nm process and 246 mm² die size are shared, meaning the physical design is unchanged. The only meaningful architectural differentiators are the boost clock and TDP.

The Verdict

The data points to the Intel Xeon D-1520 as the performance leader, albeit by a margin that will rarely be perceptible in real-world use. It wins all six head-to-head benchmarks, including a 0.2% lead in R15 multi-core and R23 single-core, and holds a 0.1% edge in the other multi-core tests. For users who prioritize maximum benchmark scores, even by fractions of a percentage point, the D-1520 is the correct pick. Its 1209 average score is the highest among its nearest rivals, matching the Core i3-8121U and edging out the Xeon E5645 and Core i3-7300T.

The Intel Xeon D-1527 is the choice for power-sensitive deployments. Its 35 W TDP versus the D-1520’s 45 W represents a significant thermal advantage that can simplify cooling design and reduce operating costs in dense server environments. The performance cost is negligible — a 0.1% average score delta — and the single-core results are identical in two of three tests. For workloads that are not consistently multi-core saturated, the D-1527 offers nearly indistinguishable performance with a materially lower thermal footprint.

Neither chip is a clear winner for general-purpose computing. The 34th percentile ranking for both parts indicates they sit in the lower-midrange of the CPU landscape. The D-1520’s six-win sweep is statistically meaningful but practically irrelevant at these margins. The launch MSRP of $199 for the D-1520 and $213 for the D-1527 suggests the D-1520 offers better nominal value, but the D-1527’s lower TDP may justify its price premium in specific use cases. The verdict is straightforward: pick the D-1520 for benchmark leadership, pick the D-1527 for thermal efficiency.

FAQ

Q: Which processor is faster in multi-core workloads?

A: The Intel Xeon D-1520 wins all three multi-core benchmarks. It scores 421 in Cinebench R15, 1755 in R20, and 4179 in R23, each time beating the D-1527 by 0.1% to 0.2%.

Q: Do the two processors differ in single-core performance?

A: The single-core results are effectively tied. Both score 59 in Cinebench R15 and 247 in R20. The D-1520 leads by a single point in R23, 590 versus 589, a 0.2% delta.

Q: What is the thermal design power difference?

A: The D-1527 is rated at 35 W TDP, while the D-1520 is rated at 45 W. That 10 W difference is the largest specification gap between the two chips.

Q: Are these processors based on the same architecture?

A: Yes. Both use the Broadwell architecture on Intel’s 14 nm process, with 3,200 million transistors on a 246 mm² die. They share the same 4-core, 8-thread configuration and identical cache sizes.

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

A: The D-1520’s average score of 1209 matches the Intel Core i3-8121U exactly, while the D-1527’s 1207 average trails the Xeon E5645 and Core i3-7300T, both at 1211, by 0.3%.

Q: Which processor should I choose for a power-constrained server?

A: The D-1527 is the better choice for low-power designs due to its 35 W TDP. It sacrifices only 0.1% in average benchmark score compared to the D-1520, making the thermal savings nearly free in performance terms.