Intel Xeon E5-1681 v3 vs Intel Xeon E5-2678 v3 Comparison

FAQ

Q: Which processor has higher overall benchmark scores?

A: The Intel Xeon E5-1681 v3 leads in all six head-to-head Cinebench tests. Its average benchmark score is 3643 versus 3608 for the Xeon E5-2678 v3, a difference of 35 points.

Q: How does the E5-1681 v3 compare in multi-core performance?

A: The E5-1681 v3 wins every multi-core test, with margins of 1% in Cinebench R15 (1269 vs 1257), R20 (5290 vs 5239), and R23 (12597 vs 12474). Despite having fewer cores, it maintains a consistent edge.

Q: Is the single-core performance difference significant?

A: The largest single-core gap is 1.1% in Cinebench R15 (179 vs 177). In R20 the margin is 0.9% (746 vs 739), and in R23 it is 1% (1778 vs 1761). These are small but consistent wins for the E5-1681 v3.

Q: Which processor has more cores and threads?

A: The Xeon E5-2678 v3 features 12 cores and 24 threads, while the Xeon E5-1681 v3 has 10 cores and 20 threads. The E5-2678 v3 offers 20% more cores and threads.

Q: What about memory support differences?

A: The E5-1681 v3 supports DDR4 only, while the E5-2678 v3 supports both DDR3 and DDR4. Both feature quad-channel memory with identical 68.3 GB/s bandwidth and ECC support.

Q: How do these processors rank against all CPUs?

A: Both sit at the 55th percentile versus all CPUs, placing them in the same performance tier. Their nearest rivals are similarly matched, with the E5-1681 v3 trading within 0.8% of the AMD EPYC 7251 and the E5-2678 v3 within 0.2% of the Intel Xeon E-2286G.

Architecture Differences

Both processors share the same fundamental Haswell-EP architecture, built on Intel's 22 nm process node with 2,600 million transistors and a 356 mm² die size. They are both fabricated by Intel, use the Intel Socket 2011-3, and belong to the Xeon E5 (Haswell-EP) generation. Neither has integrated graphics, and both are locked (multiplier unlocked: false).

The critical architectural divergence is in core configuration. The E5-2678 v3 packs 12 cores and 24 threads, whereas the E5-1681 v3 uses 10 cores and 20 threads. This difference is offset by clock speeds: the E5-1681 v3 runs at a 2.90 GHz base clock and 3.50 GHz boost, while the E5-2678 v3 operates at 2.50 GHz base and 3.30 GHz boost. The higher clocks on the E5-1681 v3 compensate for its two fewer cores in benchmark results.

Cache hierarchies also differ. The E5-1681 v3 has 25 MB of shared L3 cache, while the E5-2678 v3 offers 30 MB of shared L3. Both processors have identical per-core L1 (64 KB) and L2 (256 KB) caches. The larger L3 on the E5-2678 v3 aligns with its additional cores but does not translate into benchmark wins.

Memory support presents a notable distinction. The E5-1681 v3 is limited to DDR4, whereas the E5-2678 v3 supports both DDR3 and DDR4. Both use quad-channel memory buses with matching 68.3 GB/s bandwidth, and both support ECC memory.

PCIe capabilities are identical: Gen 3 with 40 lanes (CPU only). Both are end-of-life products, and the E5-1681 v3 carries part number SR1Y2 while the E5-2678 v3 carries SR20Z. Neither has a listed launch MSRP.

Head-to-Head Benchmarks

The benchmark data is unambiguous: the E5-1681 v3 wins all six Cinebench tests, with every margin within a narrow 0.9% to 1.1% range. This consistency indicates that the higher clock speeds of the E5-1681 v3 fully offset the core-count advantage of the E5-2678 v3.

In Cinebench R15 multi-core, the E5-1681 v3 scores 1269 versus 1257 for the E5-2678 v3, a 1% advantage. The single-core R15 test shows a 1.1% gap (179 vs 177), the largest margin in any test. These results establish a pattern: even at lower thread counts, the E5-1681 v3's frequency advantage prevails.

Moving to Cinebench R20, the multi-core scores are 5290 and 5239, again a 1% difference favoring the E5-1681 v3. The single-core R20 test narrows the gap to 0.9% (746 vs 739). This slight reduction in single-core margin suggests the E5-2678 v3's architecture scales marginally better under this workload, though not enough to overtake.

Cinebench R23 follows the same trend. Multi-core scores are 12597 for the E5-1681 v3 and 12474 for the E5-2678 v3, a 1% spread. Single-core results are 1778 versus 1761, also a 1% difference. The consistency across three Cinebench generations indicates that the performance relationship is stable and predictable.

The E5-1681 v3's average benchmark score of 3643 places it 35 points ahead of the E5-2678 v3's 3608 average. This difference is small in absolute terms but uniform across all tests. Notably, the E5-1681 v3 achieves this with 10 cores versus 12, meaning its per-core efficiency is substantially higher.

The E5-2678 v3's nearest rival comparison shows it trading with the AMD Ryzen 7 PRO 1700 (deltaPct -0.1%) and AMD Ryzen 7 2700E (deltaPct 0.1%), while the E5-1681 v3 sits near the Intel Core i9-10885H (deltaPct -0.2%) and Intel Xeon E5-2658A v3 (deltaPct -0.4%). Both processors occupy the same competitive neighborhood, reinforcing their similar performance tiers.

The Verdict

The data points decisively to the Intel Xeon E5-1681 v3 as the faster processor in every measured scenario. Its sweep of all six Cinebench tests, including both single-core and multi-core workloads, demonstrates that clock speed trumps core count in these Haswell-EP parts. The 2.90 GHz base and 3.50 GHz boost clocks of the E5-1681 v3 overcome the two-core deficit against the E5-2678 v3, which runs at 2.50 GHz base and 3.30 GHz boost.

For workloads that prioritize raw single-threaded performance, such as lightly threaded applications or tasks with serial bottlenecks, the E5-1681 v3 holds a consistent edge. The 1.1% single-core R15 advantage and 1% R23 advantage are modest but real, and they compound over thousands of operations.

For multi-threaded workloads, the E5-2678 v3's 12 cores versus 10 cores might seem advantageous, but the benchmark results contradict this expectation. The E5-1681 v3 leads by 1% in all three multi-core tests, indicating that its higher frequency more than compensates for the missing cores. The E5-2678 v3's 30 MB L3 cache versus 25 MB does not translate into a performance win.

Memory flexibility is the one area where the E5-2678 v3 offers a practical advantage. Its support for both DDR3 and DDR4 gives system builders more options for existing memory inventories, whereas the E5-1681 v3 is confined to DDR4. This could influence platform decisions despite the performance gap.

Both processors are end-of-life products with a 55th percentile ranking versus all CPUs. The E5-1681 v3's average benchmark score of 3643 is within 0.2% of the Intel Core i9-10885H, while the E5-2678 v3's 3608 average is within 0.1% of the Intel Xeon E-2286G. Neither processor offers a meaningful competitive advantage over its nearest rivals.

Specification Differences

| Specification | Intel Xeon E5-1681 v3 | Intel Xeon E5-2678 v3 |

|---|---|---|

| Cores | 10 | 12 |

| Threads | 20 | 24 |

| Base Clock | 2.90 GHz | 2.50 GHz |

| Boost Clock | 3.50 GHz | 3.30 GHz |

| TDP | 135 W | 120 W |

| L3 Cache | 25 MB (shared) | 30 MB (shared) |

| Memory Support | DDR4 | DDR3, DDR4 |

| Part Number | SR1Y2 | SR20Z |

The TDP difference is notable: the E5-1681 v3 draws 135 W versus 120 W for the E5-2678 v3, reflecting its higher clock speeds. The E5-1681 v3 also has a higher base clock by 0.40 GHz and a higher boost clock by 0.20 GHz.

Where Each One Wins

The E5-1681 v3 wins in every benchmark category, making it the default choice for performance-sensitive applications. Its higher clocks benefit single-threaded workloads like legacy software, database queries with serial execution paths, and development tasks that rely on compilation speed. The 1% multi-core advantage also makes it preferable for rendering, video encoding, and scientific computing, even with fewer cores.

The E5-2678 v3 wins in scenarios where its additional cores and larger cache might matter in future workloads not captured by Cinebench, and where memory flexibility is paramount. Its DDR3 support allows deployment in systems with existing DDR3 memory infrastructure, potentially reducing upgrade costs. The lower 120 W TDP also makes it slightly more power-efficient, which could matter in dense server deployments.

For new builds with DDR4 memory, the E5-1681 v3 is the clear pick based on benchmark data. For upgrades to existing DDR3 platforms, the E5-2678 v3 offers a viable path with slightly lower performance but broader memory compatibility. Both processors are end-of-life, so availability and platform compatibility should drive the final decision alongside the marginal performance differences documented here.