AMD EPYC 7251 vs Intel Xeon E5-1681 v3 Comparison

The AMD EPYC 7251 and Intel Xeon E5-1681 v3 are two server processors from different eras, with the EPYC built on a newer 14 nm process and the Xeon on 22 nm. The benchmark data shows a remarkably tight competition, with the EPYC 7251 winning every single head-to-head test, yet the margins are consistently under one percent. The EPYC 7251’s average benchmark score of 3671 places it at the 56th percentile of all CPUs, while the Xeon E5-1681 v3’s 3643 average places it at the 55th percentile. These are not processors that separate themselves by raw speed; the differences are in platform capabilities, core counts, and the specific workloads that favor those traits.

Head-to-Head Benchmarks

The most striking finding is that the AMD EPYC 7251 wins all six Cinebench comparisons, but the largest margin is a mere 0.8%. In the Cinebench R15 multicore test, the EPYC 7251 scores 1279 against the Xeon’s 1269, a 0.8% advantage. The single-core R15 result is nearly identical: 180 for the EPYC versus 179 for the Xeon, a 0.6% edge. Moving to Cinebench R20, the EPYC 7251 posts 5331 in multicore versus 5290 for the Xeon, again a 0.8% lead; the single-core score is 752 versus 746, another 0.8% margin. The pattern holds in Cinebench R23: the EPYC 7251’s multicore score of 12694 beats the Xeon’s 12597 by 0.8%, and the single-core score of 1792 beats 1778 by the same 0.8%. These deltas are within run-to-run noise for most workloads, meaning the two chips are effectively equal in single-threaded and lightly threaded performance.

What explains this parity? The Xeon E5-1681 v3 has 10 cores and 20 threads against the EPYC 7251’s 8 cores and 16 threads. However, the EPYC 7251 compensates with a higher per-core L2 cache (512 KB per core versus 256 KB per core) and a larger shared L3 cache (32 MB versus 25 MB). The Xeon’s higher base clock of 2.90 GHz and boost clock of 3.50 GHz should give it a clock-speed advantage, but the EPYC’s newer Zen architecture and better memory bandwidth (153.6 GB/s versus 68.3 GB/s) close the gap. The data suggests that the EPYC 7251’s architectural efficiency offsets the Xeon’s two extra cores and higher clocks in these Cinebench workloads. The average benchmark scores reinforce this: the EPYC 7251’s 3671 average is nearly identical to the Xeon’s 3643, with the EPYC 7251’s nearest rival being the AMD Ryzen 7 PRO 1700X at 3673 (a -0.1% delta), while the Xeon’s nearest rival is the Intel Core i9-10885H at 3651 (a -0.2% delta).

The Verdict

The data points to a clear conclusion: for pure Cinebench performance, the AMD EPYC 7251 is the winner, but the margin is negligible. With 6 wins out of 6 head-to-head benchmarks, the EPYC 7251 takes the crown, yet a 0.8% difference in multicore and single-core scores is not a reason to choose one over the other. The real decision hinges on platform features and future-proofing. The EPYC 7251 is an active product on the AMD Socket SP3 platform, supporting eight-channel DDR4 memory and offering 153.6 GB/s of memory bandwidth. The Xeon E5-1681 v3 is end-of-life, uses the Intel Socket 2011-3 platform, and supports only quad-channel memory with 68.3 GB/s bandwidth. If you are building a new system today, the EPYC 7251’s active status and vastly superior memory bandwidth make it the logical choice, even if the benchmark scores are nearly tied. The Xeon E5-1681 v3 only makes sense if you already own a compatible LGA 2011-3 motherboard and need its 10 cores for a specific workload that scales with core count beyond what the benchmarks show. For all other buyers, the EPYC 7251 is the safer investment, given its newer process node (14 nm versus 22 nm) and continued production.

Where Each One Wins

The benchmark results show the EPYC 7251 winning every Cinebench test, but the margins are so small that they do not indicate a meaningful performance advantage in real-world rendering or encoding. Instead, the wins are more about architectural efficiency: the EPYC 7251’s 96 KB of L1 cache per core and 512 KB of L2 cache per core give it a per-thread cache advantage that helps in latency-sensitive tasks, while its 32 MB of shared L3 cache aids in workloads that reuse data across cores. The Xeon E5-1681 v3, with 10 cores and 20 threads, has a raw core-count advantage that should help in heavily threaded workloads, but the data shows it loses in Cinebench multicore tests anyway. That suggests the Xeon’s extra cores are not being fully utilized in these specific benchmarks, or that its 25 MB of shared L3 cache and 256 KB of L2 cache per core create bottlenecks. The EPYC 7251 also wins on memory bandwidth, offering 153.6 GB/s versus the Xeon’s 68.3 GB/s, which is a massive difference that will favor the EPYC in memory-bound applications like database workloads or large-scale data processing. The Xeon E5-1681 v3’s only potential edge is its higher base clock (2.90 GHz versus 2.10 GHz) and boost clock (3.50 GHz versus 2.90 GHz), which could help in lightly threaded tasks, but the single-core benchmark results show the EPYC 7251 still wins by 0.6% to 0.8%, so even that advantage does not materialize in Cinebench.

FAQ

Q: Which CPU has a higher multicore score in Cinebench R23?

A: The AMD EPYC 7251 scores 12694 in Cinebench R23 multicore, while the Intel Xeon E5-1681 v3 scores 12597. The EPYC 7251 wins by 0.8%.

Q: Does the Intel Xeon E5-1681 v3 have more cores?

A: Yes, the Xeon E5-1681 v3 has 10 cores and 20 threads, whereas the AMD EPYC 7251 has 8 cores and 16 threads. Despite having fewer cores, the EPYC 7251 wins all multicore benchmarks.

Q: What is the memory bandwidth difference between the two?

A: The AMD EPYC 7251 supports eight-channel DDR4 memory with a bandwidth of 153.6 GB/s, while the Intel Xeon E5-1681 v3 supports quad-channel DDR4 memory with a bandwidth of 68.3 GB/s. The EPYC 7251 has more than double the memory bandwidth.

Q: Which processor has a higher single-core score in Cinebench R20?

A: The AMD EPYC 7251 scores 752 in Cinebench R20 single-core, while the Intel Xeon E5-1681 v3 scores 746. The EPYC 7251 wins by 0.8%.

Q: Is the Intel Xeon E5-1681 v3 still in production?

A: No, the Xeon E5-1681 v3 is marked as end-of-life in the data, while the AMD EPYC 7251 is listed as active and still in production.

Q: How do the average benchmark scores compare?

A: The AMD EPYC 7251 has an average benchmark score of 3671, placing it at the 56th percentile of all CPUs. The Intel Xeon E5-1681 v3 has an average score of 3643, placing it at the 55th percentile. The difference is less than 1%.

Architecture Differences

The AMD EPYC 7251 is built on the Zen architecture with the codename Naples, part of the EPYC 7001 series. It uses a 14 nm process node from GlobalFoundries, with 4,800 million transistors on a 213 mm² die. The Intel Xeon E5-1681 v3 uses the Haswell architecture with the codename Haswell-EP, built on a 22 nm process from Intel, with 2,600 million transistors on a 356 mm² die. The EPYC 7251’s newer process node allows for higher transistor density and better power efficiency, though both CPUs have a similar TDP (120 W for the EPYC, 135 W for the Xeon). The EPYC 7251 features 96 KB of L1 cache per core and 512 KB of L2 cache per core, with a 32 MB shared L3 cache. The Xeon E5-1681 v3 has 64 KB of L1 cache per core and 256 KB of L2 cache per core, with a 25 MB shared L3 cache. The EPYC 7251 also supports eight-channel memory, while the Xeon supports quad-channel memory. Both CPUs support DDR4 memory and have ECC memory support, and both use PCIe Gen 3, but the Xeon has 40 lanes (CPU only). The EPYC 7251 uses the AMD Socket SP3, while the Xeon uses Intel Socket 2011-3. The EPYC 7251 has an unlocked multiplier, whereas the Xeon does not.

Specification Differences

The key specification differences between the two CPUs are substantial. The AMD EPYC 7251 has 8 cores and 16 threads, while the Intel Xeon E5-1681 v3 has 10 cores and 20 threads. The EPYC 7251 runs at a base clock of 2.10 GHz and a boost clock of 2.90 GHz, while the Xeon runs at a base clock of 2.90 GHz and a boost clock of 3.50 GHz. The TDP is 120 W for the EPYC and 135 W for the Xeon. The EPYC 7251 has a larger L3 cache at 32 MB shared, versus 25 MB shared on the Xeon. The memory bus differs significantly: the EPYC 7251 is eight-channel with 153.6 GB/s bandwidth, while the Xeon is quad-channel with 68.3 GB/s bandwidth. The EPYC 7251 is manufactured on a 14 nm process with 4,800 million transistors, while the Xeon uses a 22 nm process with 2,600 million transistors. The EPYC 7251 has a smaller die size at 213 mm² versus 356 mm² for the Xeon. The production status also differs: the EPYC 7251 is active, while the Xeon E5-1681 v3 is end-of-life. The EPYC 7251 has an unlocked multiplier, while the Xeon is locked. The release dates are also different, with the EPYC 7251 releasing later, but the exact dates are not needed to establish that the EPYC is the newer platform.