Intel Xeon E3-1275 v5 vs Intel Xeon E3-1280 v5 Comparison

The Intel Xeon E3-1275 v5 and Intel Xeon E3-1280 v5 are two closely matched server and workstation processors from the same Skylake generation, both aimed at the same socket and market segment. At first glance, they appear nearly identical, sharing the same core count, process node, and cache layout. The recorded benchmark data, however, reveals a consistent, if small, edge for one of them across every single test. This analysis breaks down the measured performance differences, architectural choices, and specification gaps to help determine which processor suits which workload.

Head-to-Head Benchmarks

The head-to-head data in the database shows a clean sweep. The Intel Xeon E3-1275 v5 wins all six recorded benchmark tests, while the Intel Xeon E3-1280 v5 wins none. The margins are narrow, but they are uniform. In the Cinebench R15 multi-core test, the E3-1275 v5 scores 712 points against 707 points for the E3-1280 v5, a difference of 0.7 percent. The single-core R15 test shows the E3-1275 v5 posting a score of 100 versus 99, a 1 percent lead. This is the largest percentage gap in the entire comparison.

Moving to Cinebench R20, the pattern repeats. The E3-1275 v5 records 2967 in multi-core, while the E3-1280 v5 manages 2946, again a 0.7 percent advantage. In single-core, the E3-1275 v5 scores 418 against 415, another 0.7 percent edge. Cinebench R23 follows the same trend: 7065 versus 7015 in multi-core (0.7 percent), and 997 versus 990 in single-core (0.7 percent). The consistency of this 0.7 percent gap across three different rendering workloads suggests a structural advantage for the E3-1275 v5, rather than random variation. The E3-1280 v5 never pulls ahead in any of the six measurements.

What makes this interesting is the specification similarity. Both processors have the same boost clock of 4.00. The E3-1280 v5 actually has a higher base clock of 3.70, compared to the E3-1275 v5’s 3.60. Yet the measured performance does not follow the clock speed. The data implies that the E3-1275 v5’s slightly slower base frequency is compensated by other factors, allowing it to edge out in both single-core and multi-core tests. The aggregate average benchmark score confirms this: the E3-1275 v5 sits at 2043, while the E3-1280 v5 sits at 2029, a performance difference of roughly 0.7 percent across all workloads.

Where Each One Wins

The use-case split is straightforward. The Intel Xeon E3-1275 v5 wins in every measured workload category. For single-threaded tasks, the database shows it consistently ahead, whether in R15 (100 versus 99), R20 (418 versus 415), or R23 (997 versus 990). These are small advantages, but in a single-threaded application that relies on one core, any extra points can translate into slightly faster response times. For multi-threaded rendering, the E3-1275 v5 also leads, with margins of 0.7 percent across all three Cinebench versions. The average benchmark score of 2043 versus 2029 supports the same conclusion: the E3-1275 v5 is the better performer for both single-core tasks and fully threaded workloads.

The Intel Xeon E3-1280 v5 holds no measured wins in any of the six test scenarios. Its higher base clock does not translate into any benchmark advantage in the recorded data. In fact, it consistently trails by the same 0.7 percent in every test that uses more than one core. The only area where it might be said to win is in raw clock specification for sustained all-core operation, but the measurements do not reflect a performance benefit. For a user deciding purely on benchmark results, the E3-1275 v5 is the stronger choice across the board.

Architecture Differences

Both processors are built on the same Skylake architecture, specifically the Skylake-DT codename, and belong to the same generation of Xeon E3 processors. They are both manufactured on Intel’s 14 nm process node, with the same foundry. The transistor count is identical at 1,750 million, and the die size is also the same at 122 mm². The cache hierarchy matches exactly: 64 KB of L1 cache per core, 256 KB of L2 cache per core, and 8 MB of shared L3 cache. Neither has any additional 3D V-Cache.

The socket is the same Intel Socket 1151. Memory support is where a significant architecture difference appears. The E3-1275 v5 supports both DDR3 and DDR4 memory, while the E3-1280 v5 only supports DDR4. Both use a dual-channel memory bus. The E3-1275 v5 has a recorded memory bandwidth of 34.1 GB/s, while the E3-1280 v5 has no memory bandwidth figure in the database. This suggests the E3-1275 v5 is more flexible for systems that might still rely on older DDR3 memory, whereas the E3-1280 v5 is strictly for DDR4 platforms.

Another key architectural difference is integrated graphics. The E3-1275 v5 includes Intel’s HD Graphics P530, while the E3-1280 v5 has no integrated graphics at all. This means the E3-1275 v5 can output video without a separate graphics card, while the E3-1280 v5 requires a discrete GPU or a motherboard with a compatible video controller. Both processors support ECC memory, and both have the same PCIe interface: Gen 3 with 16 lanes from the CPU. Neither has an unlocked multiplier, so they are not designed for overclocking.

Specification Differences

Comparing the two specification sheets, the differences are limited but notable. The base clock differs: the E3-1275 v5 runs at 3.60 GHz, while the E3-1280 v5 runs at 3.70 GHz. That is the only clock speed difference, as both boost to 4.00 GHz. Memory support is the second difference: the E3-1275 v5 accepts both DDR3 and DDR4, but the E3-1280 v5 accepts only DDR4. The E3-1275 v5 lists a memory bandwidth of 34.1 GB/s, while the E3-1280 v5 has no such figure recorded. Integrated graphics sets them apart again: the E3-1275 v5 has the HD Graphics P530, whereas the E3-1280 v5 has none.

The launch MSRP also differs significantly. The E3-1275 v5 has a launch MSRP of $350, while the E3-1280 v5 has a launch MSRP of $612. That is a substantial price gap for a processor that performs slightly worse in every benchmark. Both are listed as end-of-life production status, both released on the same date in October 2015, and both share the same part number formatting (SR2LKSR2CT for the E3-1275 v5, SR2LC for the E3-1280 v5). The E3-1275 v5 also has a slightly higher average benchmark score (2043 versus 2029) and the same percentile rank at 45 percent of all CPUs. The E3-1280 v5’s nearest rival in the database is the Intel Xeon E3-1260L v5, with a score of 2029, while the E3-1275 v5’s closest match is the AMD Ryzen 5 7520U, also around 2043.

FAQ

Q: Which processor has a higher base clock speed?

A: The Intel Xeon E3-1280 v5 has a base clock of 3.70 GHz, while the Intel Xeon E3-1275 v5 has a base clock of 3.60 GHz. Both have the same boost clock of 4.00 GHz.

Q: Does the E3-1280 v5 ever outperform the E3-1275 v5 in the recorded benchmarks?

A: No. The E3-1275 v5 wins all six head-to-head benchmark tests, including every Cinebench version, with margins ranging from 0.7 percent to 1 percent. The E3-1280 v5 has zero wins in the recorded data.

Q: What is the difference in memory support between the two?

A: The E3-1275 v5 supports both DDR3 and DDR4 memory, while the E3-1280 v5 only supports DDR4. Both use a dual-channel memory bus, and the E3-1275 v5 has a recorded bandwidth of 34.1 GB/s.

Q: Which processor includes integrated graphics?

A: The Intel Xeon E3-1275 v5 includes HD Graphics P530. The Intel Xeon E3-1280 v5 has no integrated graphics, requiring a separate GPU for display output.

Q: How does the average benchmark score compare between the two?

A: The E3-1275 v5 has an average benchmark score of 2043, while the E3-1280 v5 has an average score of 2029, a difference of about 0.7 percent. Both have the same percentile ranking of 45 percent against all CPUs.

Q: Are there any major cache differences?

A: No. Both processors have the same cache configuration: 64 KB L1 per core, 256 KB L2 per core, and 8 MB shared L3 cache.

The Verdict

Based strictly on the measured data, the Intel Xeon E3-1275 v5 is the superior processor in nearly every measurable way. It wins all six benchmark tests, has a higher average score (2043 versus 2029), supports both DDR3 and DDR4 memory, includes integrated graphics, and has a lower launch MSRP of $350 compared to $612 for the E3-1280 v5. The only specification where the E3-1280 v5 leads is base clock speed (3.70 GHz versus 3.60 GHz), but that does not translate into any benchmark win. The E3-1280 v5 also lacks integrated graphics and only supports DDR4, making it less flexible in system builds.

For any user choosing based on the database results, the E3-1275 v5 is the superior option. It offers better or equal performance in every recorded test, additional memory flexibility, and built-in graphics, all at a lower launch price. The E3-1280 v5 could be chosen if a system specifically requires a 3.70 GHz base clock and does not need integrated graphics, but the benchmark data does not support any performance benefit from that higher base clock. In fact, the E3-1275 v5’s consistent 0.7 percent lead in multi-core and 1 percent lead in single-core suggests that the E3-1280 v5’s higher base frequency is not an effective advantage, possibly due to thermal or power characteristics. The only reason to select the E3-1280 v5 would be if a platform absolutely cannot use DDR3 memory and the user does not care about the integrated graphics or the price difference, but the recorded measurements indicate no scenario where the E3-1280 v5 is faster. The E3-1275 v5 is the better processor according to the data.