Intel Core i7-3820 vs Intel Xeon E3-1220 v5 Comparison

The Intel Core i7-3820 and the Intel Xeon E3-1220 v5 are both end-of-life processors, but they represent very different design philosophies and target completely different platforms. The i7-3820 is a desktop enthusiast part built on the Sandy Bridge-E architecture, while the Xeon E3-1220 v5 is a server and workstation chip based on the much newer Skylake architecture. The benchmark data in the database shows a curious outcome: despite the Xeon being several generations newer and built on a much smaller manufacturing process, the older i7-3820 wins every single head-to-head test, albeit by very narrow margins.

Head-to-Head Benchmarks

The database records six direct benchmark comparisons between these two CPUs, and the Intel Core i7-3820 comes out ahead in all of them. The margins are consistently small, ranging from 1.4% to 1.6%. In the Cinebench R15 multicore test, the i7-3820 scores 496 against the Xeon's 488, a 1.6% advantage. The single-core R15 result follows the same pattern: 69 for the i7-3820 versus 68 for the Xeon, a 1.5% lead.

Moving to Cinebench R20, the multicore test shows 2067 for the i7-3820 and 2034 for the Xeon, again a 1.6% difference. The single-core R20 result is 291 versus 287, a 1.4% margin. In the more recent Cinebench R23 suite, the multicore result is 4923 for the i7-3820 and 4845 for the Xeon, a 1.6% gap. The single-core R23 test rounds out the sweep with 695 versus 684, another 1.6% advantage for the i7-3820.

The takeaway from these numbers is that the i7-3820 holds a slight but consistent edge across every workload tested. The largest single advantage is 1.6% in four different tests, while the smallest is 1.4% in the R20 single-core run. None of these differences represent a dramatic performance gap, but the consistency is notable. The Xeon never manages to take a single test, even the single-core workloads where its newer architecture might be expected to excel.

Looking at the broader database context, both processors sit at the 37th percentile among all CPUs. The i7-3820 has an average benchmark score of 1424, while the Xeon E3-1220 v5 has 1401. The nearest rivals for the i7-3820 include the Intel Xeon Bronze 3106 with an average score of 1422 (a 0.1% difference), the Intel Core i5-4570S at 1426 (0.2% lower), and the Intel Core i7-3720QM at 1421 (0.2% higher). For the Xeon, the closest competitors are the Intel Xeon E-2104G at 1402 (a 0% difference), the Intel Core i5-6500TE at 1399 (0.1% higher), and the Intel Pentium Gold G7400TE at 1404 (0.2% lower). These figures show that both chips are closely matched with their immediate peers, and the difference between the two processors themselves is within the range of variance seen among their respective rivals.

FAQ

Q: Which processor has higher clock speeds?

A: The Intel Core i7-3820 has a base clock of 3.60 GHz and a boost clock of 3.80 GHz. The Intel Xeon E3-1220 v5 has a base clock of 3.00 GHz and a boost clock of 3.50 GHz.

Q: Does the Xeon support ECC memory?

A: Yes, the Intel Xeon E3-1220 v5 supports ECC memory. The Intel Core i7-3820 does not support ECC memory.

Q: Which processor has more threads?

A: The Intel Core i7-3820 has 8 threads (4 cores with Hyper-Threading), while the Intel Xeon E3-1220 v5 has 4 threads (4 cores without Hyper-Threading).

Q: What is the memory bandwidth difference?

A: The Intel Core i7-3820 has a memory bandwidth of 51.2 GB/s thanks to its quad-channel memory bus. The Intel Xeon E3-1220 v5 has a memory bandwidth of 34.1 GB/s with its dual-channel memory bus.

Q: Which processor has a larger L3 cache?

A: The Intel Core i7-3820 has 10 MB of shared L3 cache, while the Intel Xeon E3-1220 v5 has 8 MB of shared L3 cache.

Q: Are both processors unlocked for overclocking?

A: No. The Intel Core i7-3820 has an unlocked multiplier, while the Intel Xeon E3-1220 v5 has a locked multiplier.

Where Each One Wins

The Intel Core i7-3820 wins in all six recorded benchmark comparisons, so the use-case split is largely about where those wins matter. The 1.6% multicore advantage in R15, R20, and R23 suggests that the i7-3820 is slightly better suited for heavily threaded workloads. This makes sense given its 8 threads versus the Xeon's 4 threads. The extra threads allow the i7-3820 to handle parallel processing tasks with a bit more headroom, even if the per-core efficiency of the Xeon is more modern.

The single-core wins, while smaller (1.4% to 1.6%), are more surprising because the Xeon is built on a newer 14 nm process and a newer architecture. The i7-3820 compensates for its older design with higher clock speeds: 3.80 GHz boost versus 3.50 GHz boost. That frequency advantage appears to be enough to overcome the architectural improvements in the Skylake-based Xeon. For users running lightly threaded applications like older games, productivity tools, or single-threaded scripts, the i7-3820 still holds a slight edge.

The Xeon E3-1220 v5 does not win any benchmarks, but its value lies elsewhere. It supports ECC memory, which is crucial for system stability in server and workstation environments where data corruption is unacceptable. It also supports DDR3 and DDR4 memory, offering more flexibility in system builds. Its dual-channel memory bus and lower memory bandwidth (34.1 GB/s versus 51.2 GB/s) are disadvantages for memory-intensive work, but the ECC support and lower power draw are meaningful for always-on systems.

Specification Differences

The two processors differ in several fundamental specifications. The Intel Core i7-3820 uses the Intel Socket 2011 platform, while the Intel Xeon E3-1220 v5 uses the Intel Socket 1151 platform. The i7-3820 has 4 cores and 8 threads, whereas the Xeon has 4 cores and 4 threads. Base clocks are 3.60 GHz for the i7-3820 and 3.00 GHz for the Xeon, with boost clocks of 3.80 GHz and 3.50 GHz respectively.

The thermal design power (TDP) is a major differentiator: the i7-3820 draws 130 watts, while the Xeon draws only 80 watts. This is a 50 watt difference that affects cooling requirements and operating costs, especially in multi-socket server environments. Memory support also diverges: the i7-3820 supports DDR3 only, while the Xeon supports both DDR3 and DDR4. The memory bus widths differ as well, with the i7-3820 using quad-channel and the Xeon using dual-channel. Memory bandwidth reflects this: 51.2 GB/s for the i7-3820 versus 34.1 GB/s for the Xeon.

PCIe capabilities are another point of divergence. The i7-3820 offers Gen 2 with 40 lanes (CPU only), while the Xeon provides Gen 3 with 16 lanes (CPU only). The Xeon's PCIe Gen 3 support means higher bandwidth per lane, even though there are fewer lanes available. The i7-3820 has an unlocked multiplier, while the Xeon is locked. The i7-3820 was released in February 2012 with a launch MSRP of $305, while the Xeon was released in October 2015 with a launch MSRP of $203.

Architecture Differences

The architectural divide between these two chips is substantial. The Intel Core i7-3820 is based on the Sandy Bridge architecture, specifically the Sandy Bridge-E variant, and uses a 32 nm manufacturing process. It contains 1,270 million transistors on a 294 mm² die. The Intel Xeon E3-1220 v5 is based on the Skylake architecture, specifically Skylake-DT, and uses a much smaller 14 nm process. It packs 1,750 million transistors into a 122 mm² die. This means the Xeon has roughly 38% more transistors in a die that is less than half the size, reflecting the massive density improvements from process node shrinks.

Cache layouts differ as well. Both processors have 64 KB of L1 cache per core and 256 KB of L2 cache per core, but the shared L3 cache is 10 MB on the i7-3820 versus 8 MB on the Xeon. The i7-3820's larger L3 cache gives it an advantage in workloads that repeatedly access a moderate-sized working set of data.

The i7-3820 belongs to the Core i7 generation (Sandy Bridge-E) and targets the desktop market segment. The Xeon E3-1220 v5 belongs to the Xeon E3 generation (Skylake-DT) and targets the server and workstation segment. The i7-3820 has no integrated graphics, and neither does the Xeon. The i7-3820 was released in 2012, while the Xeon was released in 2015, a gap of over three years. The Xeon's newer architecture brings improvements in instruction efficiency and power management, which is reflected in its much lower 80 watt TDP, but those improvements do not translate into higher benchmark scores in the recorded tests.

The Verdict

The benchmark data is unambiguous: the Intel Core i7-3820 outperforms the Intel Xeon E3-1220 v5 in every recorded test. The margins are small, between 1.4% and 1.6%, but they are consistent across single-core and multicore workloads. If raw performance in Cinebench tests is the sole criterion, the i7-3820 is the pick. Its combination of higher clock speeds, 8 threads, and a larger 10 MB L3 cache gives it a persistent edge.

However, the Xeon E3-1220 v5 is not without reasons for consideration. It supports ECC memory, which the i7-3820 cannot use, and it draws significantly less power (80 watts versus 130 watts). Its support for both DDR3 and DDR4 memory provides platform flexibility, and its newer 14 nm process means lower thermal output in dense server chassis. The Xeon also carries a lower launch MSRP of $203 compared to the i7-3820's $305, though both parts are now end-of-life.

For a user building a system where data integrity is paramount, such as a small server or a workstation handling financial or scientific data, the Xeon's ECC support is a compelling feature that no benchmark score can capture. For a user prioritizing maximum performance in threaded applications and willing to accept higher power draw and no ECC, the i7-3820 is the clear choice. The data shows a narrow but decisive performance victory for the older i7-3820, while the Xeon wins on platform features and efficiency. The right choice depends on whether benchmark scores or system-level capabilities matter more for the intended workload.