Intel Xeon E3-1240L v5 vs Intel Xeon E5-2623 v3 Comparison

The Intel Xeon E5-2623 v3 and Intel Xeon E3-1240L v5 are both end-of-life server/workstation processors with four cores and eight threads, yet they represent two distinctly different design philosophies from Intel. The E5-2623 v3 is a Haswell-EP part built for the dual-socket capable Intel Socket 2011-3 platform, while the E3-1240L v5 is a Skylake-DT chip on the mainstream Intel Socket 1151. Despite their architectural and platform differences, benchmark results show an extraordinarily tight race: the E5-2623 v3 wins all six head-to-head Cinebench tests, but by margins of just 1.2% to 1.4% in every single instance. The data suggests that for pure compute throughput, these two CPUs are nearly interchangeable.

Where Each One Wins

The head-to-head benchmark table is unambiguous: the Intel Xeon E5-2623 v3 wins all six recorded tests, with zero wins for the E3-1240L v5. However, the magnitude of those wins tells a more nuanced story. In Cinebench R15 multicore, the E5-2623 v3 scores 568 against 560 for the E3-1240L v5, a delta of 1.4%. In Cinebench R23 multicore, the gap is 5637 versus 5564, again a 1.3% edge. Single-core tests follow the same pattern: R15 single-core shows 79 versus 78 (1.3% delta), and R23 single-core shows 795 versus 785 (1.3% delta). These are margins that would be imperceptible in real-world use, suggesting that the E5-2623 v3's advantage is theoretical rather than practical.

The E3-1240L v5's real win is not in any benchmark score but in its platform efficiency. With a TDP of 25 watts versus the E5-2623 v3's 105 watts, the E3-1240L v5 consumes a fraction of the power. This makes it the clear choice for scenarios where thermal output and energy consumption are the primary constraints—dense server racks, always-on systems, or environments with limited cooling. The E5-2623 v3, meanwhile, offers a marginal performance edge but at 4.2 times the TDP, which implies a significantly higher cooling requirement and operating cost.

Architecture Differences

The two processors come from different process nodes and microarchitectures. The E5-2623 v3 is built on Intel's 22 nm Haswell-EP architecture, while the E3-1240L v5 uses the 14 nm Skylake-DT design. This generational leap is reflected in the physical characteristics: the E5-2623 v3 has 2,600 million transistors on a 356 mm² die, whereas the E3-1240L v5 packs 1,750 million transistors into a much smaller 122 mm² die. The newer 14 nm process allows the E3-1240L v5 to achieve similar performance at dramatically lower power, explaining the 25-watt TDP.

Cache configurations differ as well. Both have 64 KB of L1 and 256 KB of L2 per core, but the E5-2623 v3 features 10 MB of shared L3 cache versus 8 MB on the E3-1240L v5. That 2 MB difference is modest but could contribute to the E5-2623 v3's slight benchmark edge in cache-sensitive workloads. Memory support also diverges sharply: the E5-2623 v3 supports DDR4 over a quad-channel bus with 59.7 GB/s of bandwidth, while the E3-1240L v5 supports both DDR3 and DDR4 over a dual-channel bus with just 34.1 GB/s. The E5-2623 v3's memory bandwidth advantage is substantial—75% higher—yet it does not translate into a significant Cinebench lead, suggesting these tests are not bandwidth-limited.

PCIe connectivity is another major differentiator. The E5-2623 v3 offers PCIe Gen 3 with 40 lanes (CPU only), while the E3-1240L v5 provides only 16 lanes. This makes the E5-2623 v3 far more capable for multi-GPU configurations or high-density storage arrays, even though the benchmark scores show no direct impact. Both processors support ECC memory and lack integrated graphics, and both have locked multipliers.

The Verdict

The benchmark data shows a virtual tie in raw processing power, with the E5-2623 v3 holding a consistent but tiny lead across all Cinebench versions. The E5-2623 v3's higher boost clock of 3.50 GHz versus 3.20 GHz on the E3-1240L v5, combined with its larger L3 cache and quad-channel memory bus, explains its systematic edge. Yet the E3-1240L v5's 25-watt TDP is its own kind of victory—it delivers 98-99% of the E5-2623 v3's performance at roughly a quarter of the power draw.

For a system builder prioritizing raw performance in a single-socket configuration, the E5-2623 v3 is the data-backed choice, but only by a hair. For anyone building a power-sensitive server or workstation where every watt counts, the E3-1240L v5's efficiency makes it the logical pick. The E5-2623 v3's 40 PCIe lanes and quad-channel memory also make it the only option for high-bandwidth I/O scenarios. The E3-1240L v5's dual-channel memory and 16 PCIe lanes are sufficient for typical server workloads but will bottleneck heavily parallel storage or GPU compute.

FAQ

Q: Which processor is faster in single-core performance?

A: The Intel Xeon E5-2623 v3 wins every single-core Cinebench test, but by margins of only 1.2% to 1.3%. In Cinebench R23 single-core, it scores 795 versus 785 for the E3-1240L v5.

Q: How do the two compare in multicore workloads?

A: Again, the E5-2623 v3 wins all multicore tests. In Cinebench R20 multicore, it scores 2367 versus 2336 for the E3-1240L v5, a 1.3% delta. The largest multicore margin is in R15, where the E5-2623 v3 leads by 1.4% (568 versus 560).

Q: What is the most significant difference between these CPUs?

A: Power consumption. The E3-1240L v5 has a TDP of 25 watts, while the E5-2623 v3 draws 105 watts. This is the largest spec gap between the two, dwarfing the sub-1.5% benchmark differences.

Q: Do both processors support ECC memory?

A: Yes, both the Intel Xeon E5-2623 v3 and the Intel Xeon E3-1240L v5 support ECC memory. However, the E5-2623 v3 uses quad-channel DDR4 with 59.7 GB/s bandwidth, while the E3-1240L v5 uses dual-channel DDR3 or DDR4 with 34.1 GB/s.

Q: Which CPU has more PCIe lanes?

A: The E5-2623 v3 offers 40 PCIe Gen 3 lanes (CPU only), compared to 16 lanes on the E3-1240L v5. This makes the E5-2623 v3 the only viable choice for multi-GPU or high-density I/O configurations.

Q: Are these processors still in production?

A: No, both are end-of-life. The E5-2623 v3 was released in September 2014, and the E3-1240L v5 followed in October 2015.

Head-to-Head Benchmarks

The head-to-head results are remarkably consistent, with the E5-2623 v3 winning every test by a narrow margin. In Cinebench R15 multicore, the E5-2623 v3 scores 568 against 560 for the E3-1240L v5, a 1.4% delta—the largest win for either CPU in any test. The R15 single-core test shows 79 versus 78, a 1.3% edge. Moving to Cinebench R20, the multicore scores are 2367 versus 2336 (1.3% delta), and single-core is 333 versus 329 (1.2% delta). In the newest Cinebench R23, the multicore result is 5637 versus 5564 (1.3% delta), while single-core is 795 versus 785 (1.3% delta).

The pattern is clear: the E5-2623 v3's advantage is real but marginal, hovering between 1.2% and 1.4% across all six tests. This consistency suggests the performance gap is structural—likely due to the E5-2623 v3's higher base clock (3.00 GHz versus 2.10 GHz) and boost clock (3.50 GHz versus 3.20 GHz). The E3-1240L v5's much lower base clock is largely compensated by its newer architecture, which achieves similar instructions per clock at lower frequencies.

Specification Differences

The two CPUs differ on nearly every specification except core count, thread count, and L1/L2 cache sizes. The E5-2623 v3 has a base clock of 3.00 GHz and a boost clock of 3.50 GHz, while the E3-1240L v5 runs at 2.10 GHz base and 3.20 GHz boost. TDP is the starkest contrast: 105 watts for the E5-2623 v3 versus 25 watts for the E3-1240L v5. The E5-2623 v3 uses the Intel Socket 2011-3 platform, while the E3-1240L v5 fits Intel Socket 1151. Architecture and process node differ—Haswell-EP on 22 nm versus Skylake-DT on 14 nm—leading to different transistor counts (2,600 million versus 1,750 million) and die sizes (356 mm² versus 122 mm²).

L3 cache favors the E5-2623 v3 at 10 MB shared, compared to 8 MB shared on the E3-1240L v5. Memory support is also different: the E5-2623 v3 supports DDR4 over a quad-channel bus with 59.7 GB/s bandwidth, while the E3-1240L v5 supports DDR3 and DDR4 over a dual-channel bus with 34.1 GB/s. PCIe connectivity differs significantly—40 lanes versus 16 lanes, both Gen 3. The launch MSRP for the E5-2623 v3 is $444, while the E3-1240L v5 launched at $278. Both are end-of-life, lack integrated graphics, have locked multipliers, and carry the same 39th percentile ranking among all CPUs.