Intel Core i7-3930K vs Intel Xeon E3-1585L v5 Comparison

The Intel Xeon E3-1585L v5 and the Intel Core i7-3930K represent two very different approaches to computing, separated by nearly five years of architectural evolution. The Xeon is a compact, power-lean server part built on 14 nm Skylake silicon, while the i7 is a six-core desktop flagship from the Sandy Bridge era on a 32 nm process. Benchmark data from the database shows a surprisingly close contest, with the older i7 narrowly edging ahead in every recorded test, despite the Xeon’s newer design. This analysis walks through those results, explores what each processor does best, and examines the architectural and specification differences that explain the data.

Head-to-Head Benchmarks

The head-to-head results are remarkably consistent. Across six Cinebench tests, the Intel Core i7-3930K wins every single one, but by margins that are almost negligible. In Cinebench R15 multi-core, the i7 scores 701 against the Xeon’s 693, a delta of -1.1% from the Xeon’s perspective. The single-core R15 test shows the same pattern: 98 for the i7 versus 97 for the Xeon, a 1% gap. These are not the kind of differences that would be noticeable in everyday use; they are within the noise of typical benchmarking variation.

Moving to Cinebench R20, the story repeats. The i7-3930K posts 2921 in multi-core, while the Xeon E3-1585L v5 manages 2888, again a 1.1% difference. Single-core R20 sees the i7 at 412 and the Xeon at 407, a 1.2% gap. The largest margin in the entire comparison appears here, but even that is only slightly over one percent. In Cinebench R23, the i7 scores 6955 multi-core and 981 single-core, against the Xeon’s 6878 and 971. The deltas are -1.1% and -1% respectively. The database records six wins for the i7-3930K and zero for the Xeon, but the practical interpretation is that these two processors are essentially tied in raw rendering performance.

What makes this interesting is the underlying hardware. The i7-3930K has six cores and twelve threads, compared to the Xeon’s four cores and eight threads. A 50% core advantage should typically translate into a much larger multi-core lead, yet the i7 only manages a 1% edge. This suggests that the Xeon’s newer Skylake architecture, with its higher instructions-per-clock efficiency, is nearly compensating for the two missing cores. The base clocks are also close: the i7 runs at 3.20 GHz base and 3.80 GHz boost, while the Xeon runs at 3.00 GHz base and 3.70 GHz boost. The i7’s slight clock advantage, combined with extra cores, should have produced a decisive win. The data shows it did not, which points to the Skylake core’s superior per-clock performance.

Single-core results reinforce this. The i7 wins by only 1% in each single-core test, despite a 0.10 GHz boost clock advantage. If Sandy Bridge and Skylake cores were equally efficient, a 2.7% clock difference would likely yield a similar performance gap. Instead, the Xeon nearly matches the i7, indicating that each Skylake core is doing more work per cycle than each Sandy Bridge core. The database’s average benchmark scores also reflect this near-equality: the Xeon averages 1989 across all its tests, while the i7 averages 1960. The Xeon’s average is actually higher, though it lacks the Geekbench results that the i7 includes in its average. Both processors sit at the 44th percentile among all CPUs tracked in the database, placing them in the same performance tier.

The Verdict

From the recorded data, the Intel Core i7-3930K is the faster processor in every benchmark where both were measured. It wins all six Cinebench tests, but by margins of only 1% to 1.2%. For anyone choosing purely on peak rendering performance, the i7 is the correct pick. However, the word “peak” matters. The Xeon E3-1585L v5 delivers nearly identical scores while consuming far less power, as its 45 W TDP versus the i7’s 130 W TDP makes clear. The data cannot tell us about real-world power draw, but the TDP figures suggest a dramatic efficiency gap.

Who should pick the Xeon? Anyone constrained by power or thermal limits. The Xeon’s 45 W TDP is less than half the i7’s 130 W, and it achieves this with only a 1% performance penalty. It also supports ECC memory, which the i7 does not, making it suitable for reliability-focused workloads. The Xeon is a server or workstation part, while the i7 is a desktop part, so the intended use case differs. The i7 has an unlocked multiplier, allowing overclocking, which could widen its performance lead beyond the stock scores recorded here. The Xeon’s multiplier is locked.

The i7-3930K also offers more platform connectivity. It provides 40 PCIe Gen 3 lanes from the CPU, compared to the Xeon’s 16 lanes. For multi-GPU setups or heavy I/O, the i7 has a clear advantage. The i7 also supports quad-channel DDR3 memory, yielding a memory bandwidth of 51.2 GB/s, while the Xeon is dual-channel with 34.1 GB/s. In memory-sensitive workloads, the i7 would likely pull further ahead, although the database’s Cinebench tests do not capture that. The verdict is thus split: the i7 wins on raw performance and expandability, the Xeon wins on efficiency and ECC support.

Where Each One Wins

The i7-3930K wins in every measured benchmark, so on paper it is the performance champion. Its six cores and twelve threads give it a structural advantage in heavily threaded workloads, even if the measured margin is small. The quad-channel memory bus and 40 PCIe lanes make it the better choice for systems that need to move large amounts of data. Overclocking potential, thanks to the unlocked multiplier, means users can push it beyond the stock scores in the database. For a desktop enthusiast building a high-end rig in 2011, this was the obvious choice.

The Xeon E3-1585L v5 wins in efficiency and feature support. Its 45 W TDP makes it suitable for compact, low-power servers or workstations where heat dissipation is a concern. The integrated Iris Pro Graphics P580 provides a GPU, which the i7 lacks entirely. For systems that do not need a discrete graphics card, the Xeon offers a complete package. ECC memory support is another win, as it enables error correction for critical data. The Xeon’s 14 nm process, versus the i7’s 32 nm, explains much of this efficiency. The Xeon’s smaller die size, 171 mm² versus 435 mm², and lower transistor count of 2,300 million versus 2,270 million, show how much more densely packed the newer process is.

In terms of use cases, the i7 suits tasks that benefit from extra cores, memory bandwidth, and PCIe lanes, such as video editing, 3D rendering, or multi-GPU compute. The Xeon suits power-constrained environments, embedded or rack-mounted systems, and any workload where data integrity matters more than absolute speed. The benchmark data shows only a 1% difference in rendering, so the choice often comes down to these non-performance factors.

FAQ

Q: Which processor is faster in Cinebench R23 multi-core?

A: The Intel Core i7-3930K scores 6955, while the Intel Xeon E3-1585L v5 scores 6878. The i7 leads by 1.1%.

Q: Does the Xeon support ECC memory?

A: Yes, the Xeon E3-1585L v5 supports ECC memory. The Core i7-3930K does not.

Q: How many PCIe lanes does each CPU provide?

A: The Xeon provides 16 PCIe Gen 3 lanes from the CPU. The i7 provides 40 PCIe Gen 3 lanes.

Q: What is the TDP difference between the two?

A: The Xeon has a TDP of 45 W, while the i7 has a TDP of 130 W. The Xeon uses less than half the power envelope.

Q: Does the i7 have integrated graphics?

A: No, the i7-3930K has no integrated graphics. The Xeon includes Iris Pro Graphics P580.

Q: Are these processors in the same performance percentile?

A: Yes, both are at the 44th percentile among all CPUs in the database, indicating similar overall standing.

Architecture Differences

The architectural gap between these two processors is significant. The Xeon E3-1585L v5 uses the Skylake architecture on a 14 nm process, with a codename of Skylake-H. The i7-3930K uses Sandy Bridge on a 32 nm process, with a codename of Sandy Bridge-E. The process node difference is stark: 14 nm versus 32 nm. This directly impacts die size, with the Xeon at 171 mm² and the i7 at 435 mm². Transistor counts are similar, 2,300 million for the Xeon and 2,270 million for the i7, but packed into much different areas.

The Xeon has 4 cores and 8 threads, while the i7 has 6 cores and 12 threads. Cache configurations differ as well. Both have 64 KB of L1 cache per core and 256 KB of L2 cache per core. However, the L3 cache is 8 MB shared on the Xeon, versus 12 MB shared on the i7. The i7’s larger L3 cache likely helps compensate for its older core design. The Xeon’s architecture is built on a newer microarchitecture that delivers more instructions per clock, which is why it nearly matches the i7 despite fewer cores.

Memory support differs fundamentally. The Xeon supports both DDR3 and DDR4, while the i7 supports only DDR3. The memory bus is dual-channel on the Xeon and quad-channel on the i7. This gives the i7 a theoretical memory bandwidth of 51.2 GB/s, versus 34.1 GB/s for the Xeon. The integrated graphics are another major difference: the Xeon includes Iris Pro Graphics P580, while the i7 has no integrated graphics at all. The Xeon also supports ECC memory, a feature absent from the i7.

The Xeon is built for the server or workstation market, while the i7 targets desktop enthusiasts. The Xeon uses an Intel BGA 1440 socket, which is soldered, while the i7 uses Intel Socket 2011, a socketed design. The i7 has an unlocked multiplier for overclocking, while the Xeon’s multiplier is locked. These architectural choices reflect their intended roles: the Xeon prioritizes efficiency, reliability, and small size, while the i7 prioritizes raw performance and user flexibility.

Specification Differences

The specifications that differ between the two processors are numerous. The Xeon E3-1585L v5 has 4 cores and 8 threads, while the i7-3930K has 6 cores and 12 threads. Base clocks are 3.00 GHz for the Xeon and 3.20 GHz for the i7. Boost clocks are 3.70 GHz for the Xeon and 3.80 GHz for the i7. TDP is 45 W for the Xeon and 130 W for the i7. The socket differs: Intel BGA 1440 for the Xeon, Intel Socket 2011 for the i7.

The architecture and process node differ, with the Xeon on Skylake and 14 nm, and the i7 on Sandy Bridge and 32 nm. Die size is 171 mm² for the Xeon and 435 mm² for the i7. Transistor counts are close, at 2,300 million and 2,270 million respectively, but the L3 cache differs: 8 MB shared on the Xeon, 12 MB shared on the i7. Memory support is DDR3 and DDR4 for the Xeon, versus DDR3 only for the i7. Memory bus is dual-channel for the Xeon and quad-channel for the i7. Memory bandwidth is 34.1 GB/s for the Xeon and 51.2 GB/s for the i7.

ECC memory support is present on the Xeon and absent on the i7. PCIe lanes are 16 for the Xeon and 40 for the i7, both Gen 3. Integrated graphics are Iris Pro Graphics P580 on the Xeon, while the i7 has none. The market segment is server or workstation for the Xeon, desktop for the i7. The multiplier is unlocked on the i7, locked on the Xeon. Release dates are May 2016 for the Xeon and November 2011 for the i7. The launch MSRP for the Xeon is $445, and for the i7 it is $583. The part numbers are SR2R9 for the Xeon and SR0GWSR0KY for the i7.