CPU Comparison

The Intel Xeon E5540 and AMD Athlon X4 850 are two end-of-life processors from different eras and market segments, yet their benchmark scores place them in a remarkably tight race. The data shows the Xeon E5540, a server-focused chip from 2009, winning all five head-to-head Cinebench comparisons against the 2015-era desktop Athlon, but the margins are consistently narrow. Across the board, the Intel part leads by deltas between 1.8% and 2.2%, making this a contest decided by inches rather than a knockout. The largest advantage for the Xeon E5540 comes in Cinebench R20 single-core, where it scores 141 against the Athlon’s 138, a 2.2% edge. In multi-core workloads, the lead narrows slightly to 1.8%, as seen in both Cinebench R20 (1001 vs 983) and Cinebench R23 (2384 vs 2342). The smallest margin is a 1.8% difference in Cinebench R23 multi-core, reinforcing that these chips are near-statistical twins in raw rendering performance despite their architectural chasm.

Head-to-Head Benchmarks

The most decisive win for the Intel Xeon E5540 is in Cinebench R20 single-core, where it posts 141 points against the AMD Athlon X4 850’s 138. That 2.2% delta is the largest margin in the entire comparison, suggesting that Intel’s older Nehalem architecture still holds an edge in lightly-threaded tasks when clock speeds are normalized. The Athlon X4 850, despite running at a much higher base clock of 3.20 GHz and boost clock of 3.90 GHz, cannot overtake the Xeon’s 2.53 GHz base and 2.80 GHz boost in this test. This is a telling result: the Xeon’s superior instructions-per-clock compensates for a 1.10 GHz deficit at boost.

In multi-core workloads, the pattern repeats but with slightly compressed margins. Cinebench R15 multi-core shows the Xeon E5540 at 240 versus the Athlon’s 235, a 2.1% win. Cinebench R20 multi-core yields 1001 for Intel versus 983 for AMD, a 1.8% gap. Cinebench R23 multi-core follows the same trajectory: 2384 for the Xeon, 2342 for the Athlon, again 1.8%. Notably, the Xeon E5540 leverages hyper-threading to present 8 threads, while the Athlon X4 850 is a pure 4-core, 4-thread design. Despite having twice the thread count, the Intel chip only manages a sub-2% lead in multi-core tests, which underscores how efficient the Athlon’s Steamroller cores are at extracting performance from its four physical cores.

The single-core Cinebench R23 result mirrors the R20 outcome: Intel wins 336 to 330, a 1.8% margin. Across all five benchmarks, the Xeon E5540 wins 5-0, but the average benchmark scores tell a similar story. The Xeon’s average score is 820, while the Athlon sits at 806, a 1.7% difference. Both processors land in the 22nd percentile of all CPUs, meaning they are statistically indistinguishable in overall performance ranking. The nearest rivals for the Xeon E5540 include the AMD PRO A10-8750B (avg score 821, delta -0.1%), the Intel Core i5-L16G7 (816, +0.5%), the Intel Xeon X3440 (815, +0.6%), and the Intel Core i7-5550U (813, +0.9%). For the Athlon X4 850, the closest competitors are the Intel Xeon X5482 (805, +0.1%), AMD Ryzen 3 2200U (805, +0.1%), Intel Core i7-870S (809, -0.3%), and AMD A10-6800K (809, -0.4%).

Where Each One Wins

The Intel Xeon E5540 wins every single benchmark in this comparison, but the practical implications are nuanced. The Xeon’s wins are consistent across both single-core and multi-core tests, meaning it is the better choice for any Cinebench-style rendering workload, regardless of thread count. Its 8-thread capability gives it a theoretical advantage in heavily parallelized applications, yet the data shows that advantage is minimal in practice, only 1.8% in R20 and R23 multi-core. The Xeon also wins in single-core tests, which is surprising given the Athlon’s much higher clock speeds. This suggests the Xeon’s Nehalem architecture handles branch prediction and instruction scheduling more efficiently than AMD’s Steamroller design, even at a 1.10 GHz clock disadvantage.

The AMD Athlon X4 850, despite losing every benchmark, has its own qualitative strengths that the data indirectly supports. Its TDP is 65 watts versus the Xeon’s 80 watts, making it a more power-efficient part on paper, though the FACT PACK provides no thermal or power consumption measurements to verify real-world impact. The Athlon also features an unlocked multiplier, enabling overclocking potential that the locked Xeon lacks. For a user willing to push clocks higher, the Athlon could potentially close or reverse the 1.8-2.2% gaps, but that is speculative since no overclocked benchmark scores are provided. The Athlon’s memory bandwidth is rated at 34.1 GB/s versus the Xeon’s 25.6 GB/s, a 33% advantage that does not translate into Cinebench wins but could benefit memory-sensitive workloads not covered in this benchmark suite. In terms of PCIe, the Athlon supports Gen 3 with 16 lanes, while the Xeon is limited to Gen 2, making the AMD part more suitable for modern graphics cards.

Architecture Differences

The architectural divide between these two chips is generational and philosophical. The Intel Xeon E5540 is built on Nehalem architecture with the Gainestown codename, fabricated on a 45 nm process at Intel’s foundry. It packs 731 million transistors into a 263 mm² die. The cache hierarchy is per-core: 64 KB of L1 and 256 KB of L2 for each of its 4 cores, plus a shared 8 MB L3 cache. Memory support is DDR3 over a triple-channel bus, yielding 25.6 GB/s of bandwidth, and it supports ECC memory, a hallmark of its server/workstation market segment. The Xeon uses Intel Socket 1366 and was released on March 29, 2009, with a launch MSRP of $774.

The AMD Athlon X4 850 is a Steamroller-architecture part with the Godaveri codename, built on a 28 nm process at GlobalFoundries. It contains 2,411 million transistors on a 245 mm² die, a significantly denser and more complex design than the Xeon. The cache layout differs sharply: 256 KB of L1 and 4 MB of L2 are shared across the 4 cores, with no L3 cache at all. Memory support is DDR3 over a dual-channel bus, but bandwidth is higher at 34.1 GB/s. ECC memory is not supported, and the chip is aimed at the desktop segment on AMD Socket FM2+. It features PCIe Gen 3 with 16 CPU-only lanes, compared to the Xeon’s Gen 2. The Athlon’s multiplier is unlocked, whereas the Xeon’s is locked. The Athlon has no release date or launch MSRP in the data, but its production status is end-of-life, matching the Xeon.

The most glaring difference is thread count: the Xeon offers 8 threads via hyper-threading, while the Athlon is strictly 4 threads. The Xeon also has a substantial L3 cache (8 MB shared) that the Athlon lacks entirely. However, the Athlon counters with a much higher clock speed (3.90 GHz boost vs 2.80 GHz boost), a smaller process node (28 nm vs 45 nm), and over three times the transistor count. The TDP difference is notable: 65 watts for AMD versus 80 watts for Intel, though the Xeon’s higher TDP is offset by its server-grade feature set like ECC support.

The Verdict

From the benchmark data alone, the Intel Xeon E5540 is the superior processor, winning all five head-to-head tests with deltas ranging from 1.8% to 2.2%. If a user’s sole criterion is Cinebench rendering performance, the Xeon is the pick, and its 8-thread capability provides a qualitative advantage in multi-threaded workloads beyond what the raw scores show. The Xeon also offers ECC memory support, which is critical for server or workstation stability, and its triple-channel memory bus, while lower bandwidth than the Athlon’s, is a more robust configuration for high-reliability systems.

However, the AMD Athlon X4 850 should not be dismissed. Its 65-watt TDP is lower, it has an unlocked multiplier for overclocking, and it supports PCIe Gen 3, making it more compatible with modern expansion cards. The Athlon’s higher memory bandwidth (34.1 GB/s) and larger L2 cache could benefit workloads not represented in the Cinebench suite, though the data does not quantify those benefits. For a desktop user building a legacy system on Socket FM2+, the Athlon is a reasonable choice. For anyone prioritizing server-grade features like ECC, the Xeon is the only option. The average benchmark scores (820 for Intel, 806 for AMD) and identical 22nd percentile ranking suggest that in real-world mixed workloads, a user would be hard-pressed to notice the difference outside of specific rendering tasks.

FAQ

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

A: The Intel Xeon E5540 scores 141, while the AMD Athlon X4 850 scores 138, giving Intel a 2.2% lead.

Q: Does the AMD Athlon X4 850 support ECC memory?

A: No, the Athlon X4 850 does not support ECC memory, whereas the Intel Xeon E5540 does.

Q: What is the TDP of each processor?

A: The Intel Xeon E5540 has a TDP of 80 watts, and the AMD Athlon X4 850 has a TDP of 65 watts.

Q: How many threads does each processor handle?

A: The Intel Xeon E5540 handles 8 threads across its 4 cores via hyper-threading. The AMD Athlon X4 850 handles 4 threads across its 4 cores, with no hyper-threading.

Q: Which chip has a higher memory bandwidth rating?

A: The AMD Athlon X4 850 is rated at 34.1 GB/s, while the Intel Xeon E5540 is rated at 25.6 GB/s.

Q: What is the average benchmark score difference between the two?

A: The Intel Xeon E5540 has an average benchmark score of 820, and the AMD Athlon X4 850 has an average of 806, a 1.7% gap in favor of Intel.