Intel Core i7-4940MX vs Intel Xeon D-1531 Comparison

The Intel Core i7-4940MX and Intel Xeon D-1531 are close competitors in aggregate benchmark scores, with the mobile Core chip averaging 1886 points and the server Xeon averaging 1885 points, a razor-thin 0.1% difference. Yet that parity masks a clear performance hierarchy: across every single benchmark in the comparison set, the Xeon D-1531 wins outright. The data shows a consistent 11.6% to 12% advantage for the Xeon in all six head-to-head tests, making this a case where the average score is misleading, and the per-test deltas tell the real story.

Head-to-Head Benchmarks

The Xeon D-1531’s dominance is uniform across both multi-core and single-core workloads. In Cinebench R23 multi-core, the Xeon scores 6517 against the i7-4940MX’s 5759, a gap of 11.6%. The single-core R23 test shows the same margin: 920 for the Xeon versus 813 for the Core i7, again 11.6%. Moving to Cinebench R20, the pattern holds — 2737 to 2418 in multi-core (11.7% delta) and 386 to 341 in single-core (11.7% delta). The oldest test in the set, Cinebench R15, shows the largest relative gap: the Xeon scores 656 versus 580 in multi-core (-12%), and 92 versus 81 in single-core (-12%).

What is striking is the consistency of the margin. Whether the workload is single-threaded or fully threaded, the Xeon D-1531 maintains roughly an 11.6% to 12% lead over the i7-4940MX. The Core i7-4940MX does not win a single benchmark in this comparison — winsA is 0, winsB is 6. That said, the aggregate average scores are nearly identical (1886 vs 1885), which means the i7-4940MX’s performance is not far off overall; it is simply behind on every individual metric measured here. Geekbench results are only available for the i7-4940MX (multicore 3869, singlecore 1227), so they cannot be compared directly, but the Cinebench suite provides a complete picture of the Xeon’s edge.

Where Each One Wins

The Xeon D-1531 wins in every benchmark category presented, making the use-case split straightforward. If the workload is any of the Cinebench R15, R20, or R23 tests — whether single-core or multi-core — the Xeon D-1531 is the faster part. For users prioritizing raw throughput in rendering or CPU-bound tasks that scale with cores, the Xeon’s 6 cores and 12 threads deliver 11.6% more multi-core performance than the i7-4940MX’s 4 cores and 8 threads. Single-core performance also favors the Xeon by 12% in R15 and 11.6% in R23, so even lightly threaded applications see a benefit.

The i7-4940MX, conversely, finds its strengths outside the measured benchmarks. It has an unlocked multiplier, whereas the Xeon D-1531 is locked, so overclocking is a possibility on the mobile part, though the data does not quantify any gains from that. The i7-4940MX also includes integrated graphics (Intel HD 4600), which the Xeon lacks entirely, making the Core chip functional without a discrete GPU. For a mobile platform, that is a meaningful advantage, even if it does not show up in CPU benchmark scores. The i7-4940MX also carries a higher boost clock (4.00 GHz vs 2.70 GHz), but the benchmark results indicate the Xeon’s newer architecture and higher core count overcome that clock disadvantage in practice.

Architecture Differences

The two processors come from different Intel microarchitectures and process nodes. The i7-4940MX is built on Haswell, a 22 nm process with 1,400 million transistors on a 177 mm² die. The Xeon D-1531 uses Broadwell, fabricated on a 14 nm node, packing 3,200 million transistors into a 246 mm² die. That newer process and larger transistor count are central to the Xeon’s performance lead, allowing 6 cores and 12 threads within a 35 W TDP, versus the i7-4940MX’s 4 cores, 8 threads, and 57 W TDP.

Cache configurations also differ. Both share 64 KB of L1 per core and 256 KB of L2 per core, but the L3 cache is organized differently. The i7-4940MX has 8 MB of shared L3 cache, while the Xeon D-1531 provides 1.5 MB per core, which across 6 cores totals 9 MB. The Xeon’s per-core L3 allocation is likely a factor in its single-core advantage, as each core has more private cache to work with. The Xeon also supports ECC memory, a feature absent from the i7-4940MX, and it supports both DDR3 and DDR4 memory, whereas the Core chip is limited to DDR3.

Another architectural difference is the PCIe implementation. The i7-4940MX has 16 PCIe Gen 3 lanes, while the Xeon D-1531 offers 24 PCIe Gen 3 lanes. The Xeon’s extra lanes are typical for a server/workstation part, enabling more expansion options. The Xeon D-1531 is also an active product, while the i7-4940MX is end-of-life, and the Xeon is based on the Broadwell-DE generation specifically for server workloads.

Specification Differences

The most obvious specification split is core and thread counts: the Xeon D-1531 has 6 cores and 12 threads, the i7-4940MX has 4 cores and 8 threads. Clock speeds favor the Core chip, with a base clock of 3.10 GHz and boost of 4.00 GHz, versus the Xeon’s 2.20 GHz base and 2.70 GHz boost. TDP also differs significantly: the i7-4940MX draws 57 W, while the Xeon D-1531 is rated at 35 W, making the Xeon more power-efficient despite having more cores.

Memory support is another differentiator. The i7-4940MX supports only DDR3 with dual-channel memory and a memory bandwidth of 25.6 GB/s. The Xeon D-1531 supports both DDR3 and DDR4, also dual-channel, but its memory bandwidth is not listed in the data. ECC memory is supported only on the Xeon. The i7-4940MX has integrated graphics (Intel HD 4600), while the Xeon has no integrated GPU. Sockets differ as well: the i7-4940MX uses Intel Socket G3, and the Xeon D-1531 uses Intel BGA 1667.

Market segments and release dates diverge. The i7-4940MX is a mobile part released in early 2014 with a launch MSRP of $1096, and it has an unlocked multiplier. The Xeon D-1531 is a server/workstation processor released in late 2015 with a launch MSRP of $348, and its multiplier is locked. The production statuses reflect their ages: the i7-4940MX is end-of-life, the Xeon D-1531 is active. Part numbers are SR1PP for the Core chip and SR2DG for the Xeon.

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Core i7-4940MX has an average benchmark score of 1886, while the Intel Xeon D-1531 scores 1885. The difference is 0.1%, with the Core chip nominally ahead, but this is within the margin of the data.

Q: How much faster is the Xeon D-1531 in Cinebench R23 multi-core?

A: The Xeon D-1531 scores 6517 in Cinebench R23 multi-core, compared to 5759 for the i7-4940MX. That is an 11.6% lead for the Xeon.

Q: Does the Core i7-4940MX win any head-to-head benchmark?

A: No. The data shows the Xeon D-1531 wins all 6 head-to-head benchmarks, with the i7-4940MX recording 0 wins and the Xeon recording 6 wins.

Q: What is the difference in core and thread counts?

A: The Xeon D-1531 has 6 cores and 12 threads, while the i7-4940MX has 4 cores and 8 threads. The Xeon also has a lower TDP of 35 W versus 57 W for the Core chip.

Q: Which processor supports ECC memory?

A: Only the Intel Xeon D-1531 supports ECC memory. The Core i7-4940MX does not list ECC support in its specifications.

Q: How do the process nodes compare between the two?

A: The i7-4940MX uses a 22 nm process with 1,400 million transistors, while the Xeon D-1531 uses a 14 nm process with 3,200 million transistors. The Xeon’s newer node contributes to its higher core count at lower power.