CPU Comparison

The AMD Opteron 4284 and Intel Xeon E5640 are both end-of-life server processors from the early 2010s, aimed at the same market segment but built on fundamentally different philosophies. The Opteron brings eight physical Bulldozer cores on a 32 nm GlobalFoundries process, while the Xeon counters with four Westmere cores and eight threads on Intel's own 32 nm process. Benchmark data from Cinebench paints a consistent picture: the AMD part wins every single head-to-head test, with margins ranging from 20% to 20.2% across both multi-core and single-core workloads. The average benchmark scores are close, 1146 for the Opteron versus 1137 for the Xeon, but the distribution of those scores reveals a clear performance hierarchy that favors the eight-core AMD design.

Where Each One Wins

Based strictly on the benchmark results, the AMD Opteron 4284 wins in every measured workload category. The head-to-head data shows five wins for the Opteron and zero for the Xeon, with the AMD chip taking both multi-core and single-core tests. In multi-core performance, the Opteron's advantage is substantial: it scores 399 versus 332 in Cinebench R15 (a 20.2% lead), 1665 versus 1387 in R20 (20% ahead), and 3965 versus 3303 in R23 (another 20% margin). These results indicate that the Opteron's eight physical cores deliver a meaningful throughput advantage over the Xeon's four cores with Hyper-Threading, even though the Xeon matches the Opteron's thread count at eight.

The single-core results are more surprising given the architectural differences. The Opteron's Bulldozer design, which uses shared floating-point units across paired cores, still manages to outpace the Westmere-based Xeon in single-threaded workloads. The Opteron scores 234 in Cinebench R20 single-core versus 195 for the Xeon, and 559 versus 466 in R23 single-core, both representing a 20% advantage. This suggests that the Opteron's higher base clock of 3.00 GHz and boost clock of 3.70 GHz, compared to the Xeon's 2.67 GHz base and 2.93 GHz boost, more than compensates for any architectural efficiency differences in single-threaded tasks.

Where the Xeon does not win in raw performance, it competes on other characteristics. The Xeon has a lower TDP at 80 watts versus the Opteron's 95 watts, and it features a triple-channel memory bus compared to the Opteron's dual-channel configuration. The Xeon also carries a larger shared L3 cache at 12 MB versus the Opteron's 8 MB shared L3. However, the benchmark data does not show these advantages translating into performance wins in any of the tested Cinebench workloads.

The Verdict

The data is unambiguous: the AMD Opteron 4284 is the faster processor in every benchmark scenario recorded. For workloads that rely on multi-threaded rendering or compute tasks, the Opteron delivers a consistent 20% performance advantage over the Xeon E5640 across all three Cinebench versions tested. The Opteron's average benchmark score of 1146 places it in the 32nd percentile of all CPUs, and its nearest rival is the Intel Core i7-2600S with an identical average score of 1146 and a 0% delta. The Xeon E5640, meanwhile, sits at an average score of 1137, also in the 32nd percentile, with its closest competitor being the Intel Core i5-2550K at 1136 (a 0.1% delta in the Xeon's favor).

Anyone choosing between these two for a legacy server or workstation should pick the Opteron 4284 if raw Cinebench performance is the priority. The 20% margins in both single-core and multi-core tests are consistent and significant. The Xeon E5640 offers a lower TDP and a triple-channel memory bus, which could matter for power-constrained or memory-bandwidth-sensitive deployments, but the benchmark data shows no performance benefit from those features in the tested workloads. The Opteron also has a higher launch MSRP of $316, which the benchmark database notes, but the Xeon's launch price is not listed, so no cost comparison is possible from the data. For end-of-life server upgrades where performance per socket is the deciding factor, the Opteron 4284 wins outright.

Head-to-Head Benchmarks

The head-to-head benchmark table is remarkably one-sided. In Cinebench R15 multi-core, the Opteron scores 399 against the Xeon's 332, a 20.2% delta that stands as the largest margin in the entire comparison. This pattern repeats in Cinebench R20 multi-core, where the Opteron posts 1665 versus 1387, a 20% advantage. The R23 multi-core test shows the same trend with 3965 versus 3303, again a 20% gap. These multi-core results are consistent across three generations of the Cinebench benchmark, indicating that the Opteron's eight-core configuration provides a durable and scalable advantage over the Xeon's four-core/eight-thread design.

Single-core results tell the same story with the same margins. The Opteron leads 234 to 195 in Cinebench R20 single-core and 559 to 466 in R23 single-core, both exactly 20% ahead. Notably, there is no Cinebench R15 single-core result for the Xeon in the data, so the head-to-head table omits that comparison. The consistency of the 20% delta across both single-core and multi-core tests suggests that the Opteron's clock speed advantage, 3.00 GHz base and 3.70 GHz boost versus 2.67 GHz and 2.93 GHz, is the dominant factor. The Xeon's larger 12 MB L3 cache and triple-channel memory interface do not compensate for the clock deficit in these benchmarks.

Looking at the nearest rivals provides additional context. The Opteron's average score of 1146 ties it exactly with the Intel Core i7-2600S (delta 0%), and it is effectively even with the Core i7-3612QE (1147, -0.1%) and the AMD Opteron 4332 HE (1144, 0.2%). The Xeon's 1137 average puts it in the same tier, just 0.8% behind the Opteron on average, but the Cinebench-specific results show a wider gap. The Xeon's closest rival, the Core i5-2550K, scores 1136 (0.1% delta), and the Core i3-N300 trails at 1135 (0.2% delta in the Xeon's favor). The percentile ranking for both processors is identical at 32, meaning neither part breaks into the upper tier of CPU performance by this metric.

FAQ

Q: Which processor has more physical cores?

A: The AMD Opteron 4284 has 8 physical cores with 8 threads, while the Intel Xeon E5640 has 4 physical cores with 8 threads via Hyper-Threading.

Q: What is the performance difference in multi-core Cinebench R23?

A: The Opteron 4284 scores 3965 in Cinebench R23 multi-core, which is 20% higher than the Xeon E5640's score of 3303.

Q: Does the Xeon E5640 win any benchmark comparison?

A: No. The head-to-head data shows the Opteron 4284 winning all 5 recorded benchmark comparisons, with the Xeon E5640 recording 0 wins.

Q: What are the clock speeds of these two processors?

A: The Opteron 4284 has a base clock of 3.00 GHz and a boost clock of 3.70 GHz. The Xeon E5640 has a base clock of 2.67 GHz and a boost clock of 2.93 GHz.

Q: How do their average benchmark scores compare?

A: The Opteron 4284 has an average benchmark score of 1146, while the Xeon E5640 averages 1137. Both processors sit in the 32nd percentile of all CPUs.

Q: Which processor has a larger L3 cache?

A: The Intel Xeon E5640 has a larger shared L3 cache at 12 MB, compared to the Opteron 4284's 8 MB shared L3 cache.

Architecture Differences

The two processors represent distinct architectural approaches from their respective manufacturers. The AMD Opteron 4284 is built on the Bulldozer architecture, codenamed Valencia, and belongs to the Opteron 4000 series. It uses 8 cores with 8 threads, fabricated on a 32 nm process at GlobalFoundries with 1,200 million transistors on a 315 mm² die. The cache hierarchy consists of 384 KB of L1, 8 MB of L2, and 8 MB of shared L3. It supports DDR3 memory via a dual-channel bus with 25.6 GB/s of bandwidth, and it includes ECC memory support. The Opteron fits the AMD Socket C32 and operates within a 95-watt TDP.

The Intel Xeon E5640, in contrast, uses the Westmere architecture, specifically the Westmere-EP codename. It has 4 cores and 8 threads, also on a 32 nm process, but fabricated at Intel with 1,170 million transistors on a smaller 239 mm² die. Its cache layout is per-core: 64 KB of L1 per core and 256 KB of L2 per core, with a larger 12 MB shared L3. Memory support is DDR3 over a triple-channel bus, and ECC memory is also supported. The Xeon uses Intel Socket 1366 and has a lower TDP of 80 watts. Both processors support PCIe Gen 2, and neither includes integrated graphics.

The transistor counts are similar, 1,200 million versus 1,170 million, but the Opteron packs those transistors into eight cores while the Xeon uses four. The Opteron's die is significantly larger at 315 mm² versus 239 mm², reflecting the additional core count. The Xeon's triple-channel memory bus gives it a theoretical memory bandwidth advantage, though the benchmark database does not list a specific bandwidth figure for the Xeon, making a direct comparison impossible. The Opteron's launch MSRP is listed at $316, while the Xeon's launch price is not provided in the data. Both processors are end-of-life and target the server/workstation segment, with the Opteron releasing in November 2011 and the Xeon in March 2010. Neither processor has an unlocked multiplier, and both are single-die designs without 3D V-Cache.