CPU Comparison

The Intel Xeon E3-1275 v5 and Intel Xeon E-2124G are both end-of-life, socket 1151 server/workstation processors with four physical cores, but the benchmark data separates them clearly. The E3-1275 v5, built on Skylake and launching in October 2015, wins every single one of the six head-to-head Cinebench comparisons against the E-2124G, which arrived in July 2018 on Coffee Lake. The average benchmark score for the E3-1275 v5 is 2043, while the E-2124G sits at 2034, and both occupy the 45th percentile among all CPUs. The data shows a consistent, roughly 16% performance gap across the board, driven primarily by the E3-1275 v5's support for 8 threads versus the E-2124G's 4 threads, combined with a higher base clock of 3.60 GHz compared to 3.40 GHz.

Head-to-Head Benchmarks

The most decisive wins for the Intel Xeon E3-1275 v5 come in multi-threaded workloads, where its Hyper-Threading advantage is fully expressed. In Cinebench R15 multicore, the E3-1275 v5 scores 712 against the E-2124G's 613, a 16.2% delta. That margin is nearly identical in Cinebench R20 multicore, where the E3-1275 v5 posts 2967 versus 2558, a 16% advantage, and in Cinebench R23 multicore, the score is 7065 versus 6092, again a 16% lead. These results indicate that the E3-1275 v5 delivers roughly one-sixth more multi-threaded throughput, a substantial margin for applications that scale with thread count.

Single-core performance tells a similar story, though the E-2124G's higher boost clock of 4.50 GHz (versus 4.00 GHz on the E3-1275 v5) does not translate into a win. In Cinebench R15 single-core, the E3-1275 v5 scores 100 against 86, a 16.3% lead. The R20 single-core test shows 418 versus 361, a 15.8% delta, and R23 single-core shows 997 versus 860, a 15.9% margin. The data suggests that the E3-1275 v5's higher base clock and older Skylake architecture still outpace the newer Coffee Lake part in single-threaded Cinebench workloads, despite the E-2124G's superior boost capability. Notably, the E-2124G has additional Geekbench results in its benchmark list, 4263 multi-core and 1438 single-core, but the E3-1275 v5 has no corresponding Geekbench entries, so those cannot be compared directly.

Across all six head-to-head tests, the E3-1275 v5 wins 6 and the E-2124G wins 0. The delta percentages are tightly clustered between 15.8% and 16.3%, indicating a uniform performance advantage rather than a workload-specific one. This consistency is unusual; most processor comparisons show at least some tests where the rival pulls ahead. Here, the E-2124G never closes the gap, even in single-threaded tests where its 4.50 GHz boost clock should theoretically help. The E3-1275 v5's nearest rivals include the AMD Ryzen 5 7520U (average score 2046, delta -0.1%) and the Intel Xeon E3-1270 v5 (average score 2048, delta -0.2%), placing it in a tight cluster. The E-2124G's nearest rivals include the AMD Ryzen 5 4500U (average score 2035, delta 0%) and the Intel Core i7-3960X (average score 2037, delta -0.1%), showing it competes with older high-end desktop parts.

The Verdict

From the data alone, the Intel Xeon E3-1275 v5 is the superior processor for almost any workload. It wins every benchmark in the head-to-head comparison, with margins ranging from 15.8% to 16.3%. Users who need maximum multi-threaded throughput, such as those running virtual machines, compiling code, or rendering, should choose the E3-1275 v5, as its 8 threads provide a measurable advantage over the E-2124G's 4 threads. The E3-1275 v5 also wins in single-threaded tests, which means even lightly threaded applications will run faster on it.

The E-2124G, however, is not without rationale. It draws less power, with a TDP of 71 watts versus 80 watts on the E3-1275 v5, and it launched at a lower MSRP of $218 compared to $350. It also supports faster memory bandwidth at 42.7 GB/s versus 34.1 GB/s, which could benefit memory-bound workloads that do not rely heavily on thread count. But the benchmark results show no scenario in this test suite where the E-2124G wins. For a system builder comparing these two on performance alone, the E3-1275 v5 is the clear choice. For a user prioritizing lower power consumption and a lower launch MSRP, the E-2124G has some appeal, but it will deliver roughly 16% less performance in Cinebench workloads.

Architecture Differences

The two processors come from different architectural generations, which explains their divergent feature sets. The E3-1275 v5 uses the Skylake architecture, specifically the Skylake-DT codename, while the E-2124G uses Coffee Lake, with the codename Coffee Lake-S WS. Both are built on Intel's 14 nm process node, and both use the same Intel Socket 1151. The E3-1275 v5 has a die size of 122 mm² and contains 1,750 million transistors, while the E-2124G has a slightly larger die at 126 mm², though its transistor count is not listed in the data.

Cache configurations are identical: both have 64 KB of L1 cache per core, 256 KB of L2 cache per core, and 8 MB of shared L3 cache. The key architectural difference is thread support. The E3-1275 v5 has 8 threads (4 cores with Hyper-Threading), while the E-2124G has only 4 threads (4 cores without Hyper-Threading). This single difference accounts for the consistent multi-core performance gap. The E3-1275 v5 also has a higher base clock (3.60 GHz versus 3.40 GHz), but the E-2124G has a higher boost clock (4.50 GHz versus 4.00 GHz).

Memory support differs as well. The E3-1275 v5 supports both DDR3 and DDR4 memory, while the E-2124G supports only DDR4. Both use dual-channel memory buses, but the E-2124G achieves a higher memory bandwidth of 42.7 GB/s compared to 34.1 GB/s on the E3-1275 v5. Integrated graphics also differ: the E3-1275 v5 has HD Graphics P530, while the E-2124G has HD Graphics P630. Both processors support ECC memory, both use PCIe Gen 3 with 16 lanes from the CPU, and both have locked multipliers. The E3-1275 v5 has two part numbers listed (SR2LK and SR2CT), while the E-2124G has one (SR3WL).

FAQ

Q: Which processor has more threads?

A: The Intel Xeon E3-1275 v5 has 8 threads, while the Intel Xeon E-2124G has 4 threads. Both have 4 cores.

Q: Does the E-2124G ever beat the E3-1275 v5 in any benchmark?

A: No. In the head-to-head data, the E3-1275 v5 wins all 6 tests, with delta percentages ranging from 15.8% to 16.3%. The E-2124G has 0 wins.

Q: What is the memory bandwidth difference?

A: The E-2124G supports 42.7 GB/s of memory bandwidth, while the E3-1275 v5 supports 34.1 GB/s. Both use dual-channel memory, but the E-2124G only supports DDR4, whereas the E3-1275 v5 supports both DDR3 and DDR4.

Q: Which processor has a higher boost clock?

A: The E-2124G has a higher boost clock at 4.50 GHz, compared to 4.00 GHz on the E3-1275 v5. However, the E3-1275 v5 still wins all single-core Cinebench tests.

Q: Are both processors the same age?

A: No. The E3-1275 v5 was released on October 18, 2015, while the E-2124G was released on July 11, 2018. Both are end-of-life.

Q: Do both processors support ECC memory?

A: Yes, both the E3-1275 v5 and the E-2124G support ECC memory. Both are classified in the Server/Workstation market segment.

Where Each One Wins

The Intel Xeon E3-1275 v5 wins in every performance category measured by the Cinebench test suite. Its 8 threads give it a decisive edge in multi-threaded workloads, as shown by the 16% leads in R15, R20, and R23 multi-core tests. It also wins in single-threaded tests, despite the E-2124G's higher boost clock, with 15.8% to 16.3% margins. The E3-1275 v5 is the better choice for any application that benefits from higher thread counts, such as rendering, video encoding, or server virtualization, based on the benchmark data.

The Intel Xeon E-2124G has no benchmark wins against the E3-1275 v5, but it does have advantages in other specifications. It consumes less power, with a TDP of 71 watts versus 80 watts, which could make it preferable for power-constrained environments. It also offers higher memory bandwidth (42.7 GB/s versus 34.1 GB/s), which could help in memory-intensive tasks that do not scale with threads. Its higher boost clock of 4.50 GHz might provide a benefit in extremely short, bursty workloads, but the Cinebench single-core results show the E3-1275 v5 still outperforms it. For users who need the fastest possible performance in Cinebench-type workloads, the E3-1275 v5 is the clear winner.

Specification Differences

The following specifications differ between the two processors:

• Threads: The E3-1275 v5 has 8 threads, while the E-2124G has 4 threads.
• Base Clock: The E3-1275 v5 runs at 3.60 GHz, the E-2124G at 3.40 GHz.
• Boost Clock: The E3-1275 v5 boosts to 4.00 GHz, the E-2124G to 4.50 GHz.
• TDP: The E3-1275 v5 has a TDP of 80 watts, the E-2124G has 71 watts.
• Architecture: The E3-1275 v5 uses Skylake (Skylake-DT), the E-2124G uses Coffee Lake (Coffee Lake-S WS).
• Die Size: The E3-1275 v5 measures 122 mm², the E-2124G measures 126 mm².
• Transistors: The E3-1275 v5 contains 1,750 million transistors; the E-2124G's transistor count is not listed.
• Memory Support: The E3-1275 v5 supports DDR3 and DDR4, the E-2124G supports only DDR4.
• Memory Bandwidth: The E3-1275 v5 has 34.1 GB/s, the E-2124G has 42.7 GB/s.
• Integrated Graphics: The E3-1275 v5 has HD Graphics P530, the E-2124G has HD Graphics P630.
• Release Date: The E3-1275 v5 launched on October 18, 2015; the E-2124G on July 11, 2018.
• Launch MSRP: The E3-1275 v5 had a launch MSRP of $350; the E-2124G had a launch MSRP of $218.
• Part Number: The E3-1275 v5 has SR2LK and SR2CT, the E-2124G has SR3WL.

Both processors share the same socket (Intel Socket 1151), process node (14 nm), L1/L2/L3 cache sizes, dual-channel memory bus, PCIe Gen 3 with 16 lanes, ECC memory support, and locked multiplier. They also both have 4 cores and are end-of-life.