Intel Core i7-3930K vs Intel Xeon E3-1231 v3 Comparison

Where Each One Wins

The benchmark data splits these two processors into clearly distinct roles. The Intel Core i7-3930K dominates the Cinebench suite, winning all six of those tests with a consistent margin. The Intel Xeon E3-1231 v3, however, counters with decisive victories in Geekbench, taking both the single-core and multi-core tests by significant percentages. This is not a case of one chip being universally superior; it is a matter of which workload generation each was designed to serve.

The i7-3930K's wins in Cinebench R15, R20, and R23, both single and multi-threaded, point to strong sustained performance in rendering tasks. The Xeon's Geekbench results suggest an advantage in memory-sensitive or latency-oriented workloads. The Xeon wins the multi-core Geekbench by 31.7%, while the i7 wins the Cinebench R23 multi-core test by 14.2%. These are opposite conclusions depending on the benchmark suite, indicating that their architectural strengths manifest differently under varied test conditions.

The recorded wins total 6 for the i7-3930K and 2 for the Xeon E3-1231 v3. Yet the magnitude of the Xeon's Geekbench victories, particularly the 79.7% margin in single-core, outweighs the narrower, though consistent, Cinebench margins of the i7. The data suggests a use-case split: the i7-3930K for traditional CPU render workloads, and the Xeon for scenarios that Geekbench measures more effectively, such as encryption, compression, or memory access patterns.

Architecture Differences

The Xeon E3-1231 v3 is built on the Haswell architecture with a 22 nm process node, while the Core i7-3930K uses Sandy Bridge-E on a 32 nm node. This generational gap is substantial. The Xeon packs 1,400 million transistors on a 160 mm² die, whereas the i7-3930K contains 2,270 million transistors spread across a much larger 435 mm² die. The larger process node of the i7 means more space and power for additional cores, but it also explains its higher 130 W TDP compared to the Xeon's 80 W.

Core and thread counts differ as expected. The Xeon has 4 cores and 8 threads, while the i7-3930K has 6 cores and 12 threads. Cache hierarchies also diverge. Both have 64 KB of L1 and 256 KB of L2 per core, but the L3 cache is 8 MB shared on the Xeon versus 12 MB shared on the i7. The extra cores and larger L3 give the i7 a structural advantage in multi-threaded workloads that can scale beyond 8 threads.

Memory support is another critical difference. The Xeon uses dual-channel DDR3 with 25.6 GB/s of bandwidth and supports ECC memory. The i7-3930K uses quad-channel DDR3, doubling the bandwidth to 51.2 GB/s, but lacks ECC support. PCIe lanes also differ: the Xeon provides 16 lanes of Gen 3, while the i7 offers 40 lanes of Gen 3. The Xeon targets the server/workstation segment, hence ECC and lower power, while the i7 is a desktop part with an unlocked multiplier. The i7's launch year of 2011 versus the Xeon's 2014 reflects the architectural gap.

Head-to-Head Benchmarks

The Cinebench results show a consistent pattern. In Cinebench R15 multi-core, the i7-3930K scores 701 against the Xeon's 601, a 14.3% difference. The single-core R15 test shows the same percentage: 98 versus 84. This exact 14.3% delta repeats across R20 multi-core (2921 vs 2506) and R20 single-core (412 vs 353). Cinebench R23 follows with the i7 at 6955 versus 5967 in multi-core and 981 versus 842 in single-core, both again at a 14.2% margin. The consistency of these deltas indicates that the i7's advantage is not workload-dependent within Cinebench; it is a flat performance lead across both single and multi-threaded rendering tests.

The Geekbench results tell a different story entirely. In Geekbench multi-core, the Xeon scores 3939 versus the i7's 2991, a 31.7% lead for the Xeon. The single-core Geekbench test is even more lopsided: the Xeon scores 1109, the i7 only 617, giving the Xeon a 79.7% advantage. This is a massive reversal. The i7's Cinebench lead of roughly 14% in every test is dwarfed by the Xeon's 31.7% and 79.7% leads in Geekbench.

What explains this? The i7 has more cores and a larger cache, which should help in multi-threaded tests, and indeed it does in Cinebench. But Geekbench's multi-core test may not scale linearly with core count, or its memory access patterns favor the Xeon's architecture. The single-core Geekbench result is particularly telling: the Xeon's Haswell architecture, with its newer process node and IPC improvements, nearly doubles the i7's Sandy Bridge score. The 22 nm process and architectural refinements of Haswell appear to deliver far better per-clock performance in Geekbench's specific workloads.

Specification Differences

The two processors differ across nearly every major specification. The Xeon E3-1231 v3 has 4 cores and 8 threads, while the i7-3930K has 6 cores and 12 threads. Base clocks are close, 3.40 GHz vs 3.20 GHz, but both boost to 3.80 GHz. TDP is a stark contrast: 80 W for the Xeon versus 130 W for the i7. Sockets are incompatible: Socket 1150 for the Xeon, Socket 2011 for the i7.

Process technology separates them by a full node generation, 22 nm versus 32 nm. Transistor counts and die sizes reflect this: 1,400 million on 160 mm² for the Xeon, 2,270 million on 435 mm² for the i7. L3 cache is 8 MB versus 12 MB. Memory bandwidth is 25.6 GB/s versus 51.2 GB/s, due to dual-channel versus quad-channel memory buses. ECC memory support is present on the Xeon only. PCIe lanes are 16 on the Xeon versus 40 on the i7.

The market segments differ, server/workstation versus desktop. The multiplier is locked on the Xeon but unlocked on the i7, allowing overclocking on the latter. Release dates are 2014 for the Xeon and 2011 for the i7. The launch MSRP for the Xeon is $250, for the i7 it is $583. The part numbers are SR1R5 for the Xeon and SR0GWSR0KY for the i7.

FAQ

Q: Which processor wins more benchmarks overall?

A: The Intel Core i7-3930K wins 6 out of 8 head-to-head tests, all of which are Cinebench R15, R20, and R23, both single and multi-core. The Intel Xeon E3-1231 v3 wins the remaining 2 Geekbench tests.

Q: Why does the Xeon win Geekbench by such a large margin?

A: The Xeon scores 3939 versus 2991 in Geekbench multi-core, a 31.7% lead, and 1109 versus 617 in single-core, a 79.7% lead. This likely stems from the Haswell architecture's improvements over Sandy Bridge, particularly in per-clock IPC.

Q: What is the biggest single-core performance difference?

A: The Geekbench single-core test shows the largest gap, with the Xeon leading by 79.7%. In contrast, Cinebench R15 single-core shows the i7 leading by only 14.3%.

Q: Does the i7-3930K have more cores?

A: Yes, the i7-3930K has 6 cores and 12 threads, while the Xeon E3-1231 v3 has 4 cores and 8 threads. The i7 also has 12 MB of L3 cache versus 8 MB on the Xeon.

Q: Which processor supports ECC memory?

A: The Xeon E3-1231 v3 supports ECC memory, while the i7-3930K does not. This is consistent with the Xeon's server/workstation market segment.

Q: How do their memory bandwidths compare?

A: The i7-3930K has quad-channel memory support delivering 51.2 GB/s, twice the 25.6 GB/s of the Xeon's dual-channel setup. This could influence multi-threaded workloads that are memory-bound.

The Verdict

The data points to a clear choice based on workload. For Cinebench rendering tasks, the i7-3930K is the stronger option. It wins every single Cinebench test by roughly 14%, regardless of thread count. The 6-core, 12-thread configuration with 12 MB of L3 cache provides a measurable edge in these multi-threaded scenarios, and even its single-core Cinebench scores are higher.

For Geekbench-style workloads, the Xeon E3-1231 v3 is decisively better. Its 79.7% lead in single-core Geekbench is not a marginal difference; it is a generational leap. The 31.7% multi-core lead is equally substantial. Anyone running applications that mirror Geekbench's test patterns, which often involve cryptography, compression, or memory access, would see far better performance from the Xeon.

The i7-3930K's additional cores and memory bandwidth make it attractive for heavily parallel workloads that fit within 12 threads. The Xeon's newer architecture, lower TDP, and ECC support make it suitable for sustained server or workstation duty. The i7 is unlocked for overclocking, the Xeon is not. The recorded data does not favor one chip universally; it favors each in its own domain. The i7-3930K for rendering, the Xeon for Geekbench-sensitive applications. The choice hinges entirely on which benchmark suite, and therefore which real-world workload, matters more to the user.