Intel Xeon E5-1681 v3 vs Intel Xeon E5-2658A v3 Comparison

The Intel Xeon E5-2658A v3 and Intel Xeon E5-1681 v3 are nearly identical in measured performance, despite clear differences in their core counts and clock speeds. Benchmark results show the E5-2658A v3 winning all six head-to-head Cinebench tests, but by extremely narrow margins—the largest delta is a mere 0.4%. The average benchmark score for the E5-2658A v3 is 3658, while the E5-1681 v3 sits at 3643, a difference of just 0.4%. Both processors occupy similar territory in the overall CPU percentile ranking, with the E5-2658A v3 at the 56th percentile and the E5-1681 v3 at the 55th. The data paints a picture of two very closely matched Haswell-EP workstation chips where architectural similarities outweigh specification differences.

The Verdict

The data suggests that the Intel Xeon E5-2658A v3 is the marginally better choice for multi-threaded workloads. It wins every single benchmark in the head-to-head comparison, including a 0.4% edge in Cinebench R23 multi-core (12647 vs 12597) and a 0.4% advantage in Cinebench R20 multi-core (5311 vs 5290). This is likely due to its 12 cores and 24 threads, which outnumber the E5-1681 v3's 10 cores and 20 threads. The E5-2658A v3 also holds a 0.4% lead in single-core tests like Cinebench R23 single-core (1785 vs 1778), despite having a lower base clock of 2.20 GHz compared to 2.90 GHz on the E5-1681 v3. The E5-2658A v3's higher average benchmark score of 3658 versus 3643 reinforces this pattern.

However, the practical difference between these two is almost negligible for real-world use. The E5-1681 v3 does offer higher clock speeds—a 2.90 GHz base and 3.50 GHz boost versus 2.20 GHz and 2.90 GHz on the E5-2658A v3. Yet this clock advantage does not translate into benchmark victories. The E5-1681 v3 loses all six head-to-head tests. For workloads that are sensitive to raw frequency, the E5-1681 v3 might feel snappier in theory, but the benchmark data does not support a performance win. The E5-2658A v3 also has a lower TDP of 105 watts versus 135 watts on the E5-1681 v3, making it the more power-efficient option based on the numbers available. Datacenter operators or workstation builders prioritizing lower thermal overhead should lean toward the E5-2658A v3. Those who require the highest possible boost clock and are willing to accept a higher TDP might consider the E5-1681 v3, but the benchmark results show they would sacrifice multi-core performance for that frequency.

FAQ

Q: Which CPU has more cores?

A: The Intel Xeon E5-2658A v3 has 12 cores and 24 threads, while the Intel Xeon E5-1681 v3 has 10 cores and 20 threads.

Q: How do their single-core performances compare?

A: In Cinebench R15 single-core, both score exactly 179. In Cinebench R20 single-core, the E5-2658A v3 scores 749 versus 746 on the E5-1681 v3, a 0.4% difference. In Cinebench R23 single-core, the E5-2658A v3 leads again with 1785 versus 1778.

Q: What is the difference in L3 cache size?

A: The E5-2658A v3 has 30 MB of shared L3 cache, while the E5-1681 v3 has 25 MB of shared L3 cache.

Q: Is there any memory bandwidth difference between the two?

A: No. Both support DDR4 memory in quad-channel configuration with a memory bandwidth of 68.3 GB/s.

Q: Which processor has a higher TDP?

A: The Intel Xeon E5-1681 v3 has a TDP of 135 watts, which is higher than the 105-watt TDP of the Intel Xeon E5-2658A v3.

Q: Are these processors still in production?

A: Both are marked as end-of-life in the data, so neither is currently in production.

Architecture Differences

Both processors share the same fundamental architecture: Intel's Haswell-EP design on a 22 nm process node, fabricated by Intel. They both have a die size of 356 mm² and contain 2,600 million transistors. The foundry is Intel for both, and they are both built for the Intel Socket 2011-3 platform. The codename for each is Haswell-EP, and their generation is listed identically as "Xeon E5 (Haswell-EP)."

The key architectural difference lies in the core configuration and cache hierarchy. The E5-2658A v3 implements 12 cores with 24 threads, while the E5-1681 v3 implements 10 cores with 20 threads. This core count difference directly influences the L3 cache allocation: the E5-2658A v3 has 30 MB of shared L3 cache, whereas the E5-1681 v3 has 25 MB. The per-core L1 cache is identical at 64 KB per core, and the per-core L2 cache is also the same at 256 KB per core. The additional two cores and 5 MB of L3 cache on the E5-2658A v3 are the primary structural advantages it holds.

Both processors lack integrated graphics, which is typical for server/workstation parts. They both support ECC memory and feature PCIe Gen 3 with 40 lanes (CPU only). The memory controllers are identical, supporting DDR4 in quad-channel mode with a bandwidth of 68.3 GB/s. Neither processor has an unlocked multiplier, so overclocking is not supported. The part numbers differ—SR27T for the E5-2658A v3 and SR1Y2 for the E5-1681 v3—but the underlying architecture is the same generation. The E5-2658A v3 has no release date listed in the data, while the E5-1681 v3 was released on 2014-09-07.

Specification Differences

The specification sheet shows clear distinctions between the two processors, even though they share the same platform and architecture. The most obvious difference is core count: the E5-2658A v3 has 12 cores versus 10 on the E5-1681 v3. Thread counts follow at 24 versus 20. Clock speeds favor the E5-1681 v3, with a base clock of 2.90 GHz and a boost clock of 3.50 GHz, compared to the E5-2658A v3's 2.20 GHz base and 2.90 GHz boost. This is a significant frequency gap—0.70 GHz at base and 0.60 GHz at boost.

The TDP also differs substantially. The E5-2658A v3 is rated at 105 watts, while the E5-1681 v3 draws 135 watts. This means the E5-1681 v3 runs hotter for its higher clock speeds. Cache sizes differ as well: the E5-2658A v3 has 30 MB of L3 cache, and the E5-1681 v3 has 25 MB. The release date is only listed for the E5-1681 v3 (2014-09-07), while the E5-2658A v3 has no release date in the data. The launch MSRP is listed only for the E5-2658A v3 at $1832; the E5-1681 v3 has no launch MSRP provided. The market segment is the same for both: Server/Workstation. Both are end-of-life products.

Head-to-Head Benchmarks

The head-to-head benchmark data shows a remarkably consistent pattern: the Intel Xeon E5-2658A v3 wins every test, but by margins so small they are almost within measurement noise. In Cinebench R15 multi-core, the E5-2658A v3 scores 1274 against 1269 for the E5-1681 v3, a 0.4% advantage. In Cinebench R15 single-core, both score an identical 179, with the winner listed as the E5-2658A v3 at a 0% delta. This tie in single-core performance is notable because the E5-1681 v3 has a much higher boost clock (3.50 GHz versus 2.90 GHz), yet it cannot outperform the E5-2658A v3 in this test.

Cinebench R20 multi-core follows the same pattern: the E5-2658A v3 scores 5311 versus 5290, a 0.4% lead. In R20 single-core, the margin is again 0.4%, with 749 versus 746. The largest absolute gap appears in Cinebench R23 multi-core, where the E5-2658A v3 scores 12647 and the E5-1681 v3 scores 12597—a 50-point difference that still translates to only 0.4%. Cinebench R23 single-core shows 1785 versus 1778, again a 0.4% delta.

The consistent 0.4% delta across most tests suggests a systematic advantage for the E5-2658A v3, likely stemming from its additional two cores and larger L3 cache. The 12-core configuration allows better parallel scaling in multi-threaded Cinebench workloads. The single-core results are more surprising. Despite a 0.60 GHz boost clock disadvantage, the E5-2658A v3 edges out the E5-1681 v3 in R20 and R23 single-core tests. This could indicate that the E5-1681 v3's higher clocks are offset by other factors, possibly thermal throttling given its 135-watt TDP, or that the benchmark's single-threaded performance is not purely clock-limited on this architecture.

Where Each One Wins

Based strictly on the benchmark data, the Intel Xeon E5-2658A v3 wins everywhere. It takes all six head-to-head tests, including both multi-core and single-core workloads. The multi-core wins are expected given its core advantage: 12 cores versus 10. For heavily threaded applications like rendering, encoding, or scientific computing, the E5-2658A v3 is the stronger performer, even if the margin is only 0.4%. It also wins the single-core tests, which is less intuitive given the E5-1681 v3's higher clock speeds. The E5-2658A v3's lower TDP of 105 watts versus 135 watts is another point in its favor for dense server deployments where thermal management is a concern.

The Intel Xeon E5-1681 v3 does not win a single benchmark in the head-to-head data. Its advantages are purely on paper: higher base and boost clocks (2.90 GHz and 3.50 GHz versus 2.20 GHz and 2.90 GHz). For workloads that are largely single-threaded and clock-bound, one might expect the E5-1681 v3 to excel, but the benchmark results show it does not. The E5-1681 v3 also has a smaller L3 cache (25 MB versus 30 MB), which could hurt in cache-sensitive workloads. The data suggests that the E5-1681 v3's higher TDP and clock speeds do not translate into any measurable performance benefit in the Cinebench suite. Its only potential advantage would be in scenarios where raw clock speed matters more than core count, but the available benchmarks do not demonstrate such a scenario.