Intel Core i5-11400T vs Intel Xeon E5-1660 v4 Comparison

The Intel Core i5-11400T and Intel Xeon E5-1660 v4 are both end-of-life desktop processors, but they target completely different eras and use cases. The benchmark data shows a remarkably consistent, albeit narrow, victory for the older Xeon part across every single test, yet the real-world decision is far more nuanced due to platform features, power envelopes, and memory support.

Head-to-Head Benchmarks

The head-to-head results are unusually one-sided. The Intel Xeon E5-1660 v4 wins all six benchmark comparisons, but the margins are surprisingly slim. In Cinebench R15, the Xeon scores 1137 against the i5-11400T’s 1120 in multi-core, a 1.5% advantage. The single-core test in R15 is closer still: 160 versus 157, a 1.9% lead for the Xeon. These are not the kind of sweeping victories that typically separate an 8-core workstation chip from a 6-core mainstream part.

Moving to Cinebench R20, the pattern holds. The Xeon E5-1660 v4 posts 4739 multi-core versus 4667 for the i5-11400T, again a 1.5% delta. Single-core shows 669 against 658, a 1.6% margin. The most modern test, Cinebench R23, repeats the theme: the Xeon scores 11285 multi-core and 1593 single-core, while the i5-11400T manages 11113 and 1569 respectively. Both deltas sit at 1.5%. The Xeon’s wins are consistent but never decisive.

These margins are smaller than what the core-count difference suggests. The Xeon has 8 cores and 16 threads against the i5’s 6 cores and 12 threads, yet it only leads by 1.5% in multi-threaded workloads. The i5-11400T’s newer Rocket Lake architecture and higher per-core efficiency close most of the gap. In the average benchmark score, the i5-11400T actually comes out ahead at 3309 versus the Xeon’s 3264, a difference of roughly 1.4% in favor of the newer chip. This means that while the Xeon wins every individual test in the head-to-head set, the i5-11400T is the stronger overall performer across a broader benchmark average, likely due to its Geekbench results where the i5 scores 5591 multi-core and 1597 single-core (the Xeon has no Geekbench data in this comparison).

Where Each One Wins

The Xeon E5-1660 v4 wins in all six direct comparisons, but the context matters. Its 8-core, 16-thread configuration gives it a slight edge in sustained multi-threaded rendering tasks like Cinebench R23, where it scores 11285 versus 11113. If you are running a workload that scales perfectly across cores and you have no power constraints, the Xeon’s 1.5% lead is real, though barely perceptible in practice. The Xeon also wins single-core tests by similar margins, meaning it is not just a brute-force chip; it holds a small IPC advantage in these legacy benchmarks.

The i5-11400T wins the overall average benchmark score race at 3309 versus 3264, which is a 1.4% advantage. This suggests it is the more balanced processor, performing better in mixed workloads and in the Geekbench suite where it posts 5591 multi-core and 1597 single-core. The i5 also benefits from a dramatically lower power draw: 35W TDP versus 140W for the Xeon. In a system that is thermally constrained or running on a smaller power supply, the i5-11400T is the clear winner because it delivers near-identical performance at a fraction of the power consumption. The Xeon’s wins are purely benchmark-based; the i5’s wins are in efficiency and overall average score.

Architecture Differences

The two CPUs come from different architectural generations and are built for different platforms. The i5-11400T is based on Rocket Lake, codenamed Rocket Lake, and belongs to the Core 11th Gen series. It uses a 14 nm process node from Intel and has a die size of 276 mm². The Xeon E5-1660 v4 is based on Broadwell, specifically Broadwell-EP, and belongs to the Xeon E5 generation. It also uses a 14 nm process node but has a smaller die at 246 mm² and contains 3,400 million transistors.

Cache structures differ significantly. The i5-11400T has 80 KB of L1 cache per core, 512 KB of L2 per core, and 12 MB of shared L3 cache. The Xeon E5-1660 v4 has 64 KB of L1 per core, 256 KB of L2 per core, and a larger 20 MB of shared L3 cache. The Xeon’s larger L3 pool helps compensate for its older architecture, while the i5’s larger per-core L1 and L2 caches boost single-thread responsiveness.

Memory support is another major split. Both support DDR4, but the i5-11400T uses a dual-channel memory bus with a bandwidth of 51.2 GB/s, while the Xeon E5-1660 v4 uses a quad-channel bus with 76.8 GB/s of bandwidth. The Xeon also supports ECC memory, which the i5 does not. PCIe capabilities are reversed in generation: the i5-11400T offers Gen 4 with 20 lanes (CPU only), whereas the Xeon E5-1660 v4 offers Gen 3 with 40 lanes (CPU only). The Xeon has no integrated graphics, while the i5-11400T includes UHD Graphics 730. Socket compatibility is entirely different: the i5 uses Intel Socket 1200, and the Xeon uses Intel Socket 2011-3.

FAQ

Q: Which CPU has more cores and threads?

A: The Intel Xeon E5-1660 v4 has 8 cores and 16 threads, while the Intel Core i5-11400T has 6 cores and 12 threads.

Q: Does the Xeon E5-1660 v4 support ECC memory?

A: Yes, the Xeon E5-1660 v4 supports ECC memory. The i5-11400T does not support ECC.

Q: Which processor has a higher boost clock?

A: The Intel Xeon E5-1660 v4 boosts to 3.80 GHz, while the Intel Core i5-11400T boosts to 3.70 GHz.

Q: What is the difference in memory bandwidth?

A: The Xeon E5-1660 v4 offers 76.8 GB/s via a quad-channel bus, while the i5-11400T offers 51.2 GB/s via a dual-channel bus.

Q: Which CPU has integrated graphics?

A: The Intel Core i5-11400T has UHD Graphics 730. The Intel Xeon E5-1660 v4 has no integrated graphics.

Q: In the head-to-head benchmarks, how often does the i5-11400T win?

A: The i5-11400T wins zero of the six head-to-head benchmark tests. The Xeon E5-1660 v4 wins all six.

Specification Differences

The two processors differ in nearly every major specification except for process node, memory type, and market segment. The i5-11400T has 6 cores and 12 threads, while the Xeon E5-1660 v4 has 8 cores and 16 threads. Base clocks differ substantially: the i5 runs at 1300 MHz, while the Xeon runs at 3200 MHz. Boost clocks are closer, with the i5 at 3.70 GHz and the Xeon at 3.80 GHz. TDP is a massive differentiator: the i5 draws 35W, while the Xeon draws 140W.

The i5 uses Intel Socket 1200, the Xeon uses Socket 2011-3. The i5 has a 276 mm² die, the Xeon a 246 mm² die; the Xeon lists 3,400 million transistors, while the i5 has no transistor count listed. Cache configurations are different: the i5 has 80 KB L1 and 512 KB L2 per core with 12 MB shared L3, while the Xeon has 64 KB L1 and 256 KB L2 per core with 20 MB shared L3. Memory bus is dual-channel for the i5 and quad-channel for the Xeon, with bandwidths of 51.2 GB/s and 76.8 GB/s respectively. ECC support is absent on the i5 and present on the Xeon. PCIe is Gen 4 with 20 lanes on the i5, versus Gen 3 with 40 lanes on the Xeon. Integrated graphics exist only on the i5. The release dates are 2021-03-15 for the i5 and 2016-06-19 for the Xeon.

The Verdict

The data points to a clear split decision. If you prioritize raw benchmark scores in Cinebench, the Intel Xeon E5-1660 v4 is the winner, taking all six head-to-head tests with margins between 1.5% and 1.9%. Its 8-core, 16-thread design and higher boost clock of 3.80 GHz give it a slight edge in both multi-threaded and single-threaded rendering tasks. It also offers ECC memory support, quad-channel bandwidth of 76.8 GB/s, and 40 PCIe Gen 3 lanes, making it the superior choice for a workstation that needs memory reliability and high I/O throughput.

However, the Intel Core i5-11400T wins the overall average benchmark score at 3309 versus 3264, indicating it is the better-rounded processor for general use. Its 35W TDP is a fraction of the Xeon’s 140W, making it far easier to cool and power. It also brings integrated graphics, PCIe Gen 4 support, and a modern socket. For a builder assembling a compact, low-power system that still delivers near-identical Cinebench performance, the i5-11400T is the rational pick. For someone with a legacy Socket 2011-3 platform needing ECC and quad-channel memory, the Xeon E5-1660 v4 is the only one that fits the bill. The benchmarks are close enough that platform requirements should dictate the choice.