Intel Core i7-990X vs Intel Xeon E3-1265L v4 Comparison

The Intel Core i7-990X and the Intel Xeon E3-1265L v4 are two end-of-life processors that land at the same spot in the overall performance distribution, yet they achieve that position through entirely different means. The i7-990X, a 6-core/12-thread desktop part from the Westmere generation, edges out the Xeon E3-1265L v4, a 4-core/8-thread server/workstation chip from the Broadwell generation, in every single head-to-head benchmark. However, the average benchmark scores are nearly identical — 1713 for the i7-990X versus 1709 for the Xeon — and both sit at the 40th percentile of all CPUs. The data shows a remarkably tight contest where the older, higher-power desktop processor holds a slim but consistent lead across all tested workloads, while the newer, far more efficient Xeon offers features the i7 cannot match.

The Verdict

The benchmark data presents a clear, if narrow, victor: the Intel Core i7-990X wins all six head-to-head comparisons against the Intel Xeon E3-1265L v4. The margins are small but uniform, ranging from a 2.4% advantage in Cinebench R15 single-core to a 2.8% lead in Cinebench R23 single-core. For users whose priority is raw computational throughput in the Cinebench suite, the i7-990X is the choice. It delivers higher scores in every test, including a 611 versus 595 result in Cinebench R15 multi-core and a 2549 versus 2482 result in Cinebench R20 multi-core.

The Xeon E3-1265L v4, however, is not without its own rationale. Its average benchmark score of 1709 trails the i7-990X by only 0.2%, placing it in the same performance tier. The Xeon's advantage lies not in speed but in its feature set and efficiency profile. It supports ECC memory, includes integrated Intel Iris Pro P6300 graphics, and operates with a TDP of 35 watts compared to the i7-990X's 130 watts. The verdict from the data is straightforward: pick the i7-990X for maximum benchmark performance, or pick the Xeon E3-1265L v4 for ECC support, integrated graphics, and dramatically lower power consumption.

Where Each One Wins

The head-to-head results show a complete sweep for the Intel Core i7-990X across all six benchmark tests. The largest winning margin for the i7-990X comes in Cinebench R23 single-core, where it scores 857 against the Xeon's 834, a 2.8% difference. The smallest margin is in Cinebench R15 single-core, with 86 versus 84, a 2.4% lead. In multi-core workloads, the i7-990X maintains a consistent 2.7% advantage across all three Cinebench versions: R15 (611 vs 595), R20 (2549 vs 2482), and R23 (6071 vs 5910).

The Xeon E3-1265L v4 does not win a single benchmark test, yet it wins in categories outside raw compute. The data shows the Xeon supports ECC memory, which the i7-990X does not. It also features integrated Intel Iris Pro P6300 graphics, a capability absent from the i7-990X, which lists no integrated graphics. The Xeon's 35-watt TDP versus the i7-990X's 130-watt TDP indicates a significant efficiency advantage, and its PCIe Gen 3 support with 16 lanes contrasts with the i7-990X's Gen 2. For workloads that prioritize memory reliability, built-in display output, or lower system power draw, the Xeon is the functional winner despite losing every compute benchmark.

Architecture Differences

The two processors come from different architectural eras and are built for different sockets. The Intel Core i7-990X uses the Westmere architecture, codenamed Gulftown, and fits into Intel Socket 1366. The Intel Xeon E3-1265L v4 uses the Broadwell architecture, codenamed Broadwell-DT, and fits into Intel Socket 1150. The manufacturing process differs substantially: the i7-990X is built on a 32 nm node, while the Xeon is built on a 14 nm node. The i7-990X has a larger die size at 239 mm² and contains 1,170 million transistors; the Xeon's die size is 182 mm² and its transistor count is not listed.

Core and cache configurations also diverge. The i7-990X offers 6 cores and 12 threads, while the Xeon offers 4 cores and 8 threads. Both share the same per-core L1 cache of 64 KB and per-core L2 cache of 256 KB, but the shared L3 cache differs: 12 MB on the i7-990X versus 6 MB on the Xeon. Memory support sees the i7-990X using triple-channel DDR3, while the Xeon uses dual-channel DDR3 with a listed memory bandwidth of 29.9 GB/s. The Xeon supports ECC memory and includes integrated Intel Iris Pro P6300 graphics; the i7-990X supports neither. The i7-990X has an unlocked multiplier, whereas the Xeon's multiplier is locked.

FAQ

Q: Which processor has a higher average benchmark score?

A: The Intel Core i7-990X has an average benchmark score of 1713, while the Intel Xeon E3-1265L v4 has an average score of 1709. The difference is 0.2%, with the i7-990X ahead.

Q: How do the two CPUs compare in multi-core performance?

A: The i7-990X wins all three multi-core Cinebench tests. It scores 611 vs 595 in R15, 2549 vs 2482 in R20, and 6071 vs 5910 in R23. Each margin is a 2.7% lead for the i7-990X.

Q: Does the Xeon E3-1265L v4 offer any features the i7-990X lacks?

A: Yes. The Xeon supports ECC memory, includes integrated Intel Iris Pro P6300 graphics, and uses PCIe Gen 3 with 16 lanes. The i7-990X has no integrated graphics, does not support ECC memory, and uses PCIe Gen 2.

Q: What is the TDP difference between the two processors?

A: The Intel Core i7-990X has a TDP of 130 watts, while the Intel Xeon E3-1265L v4 has a TDP of 35 watts. The Xeon consumes significantly less power.

Q: Which processor has more cores and threads?

A: The Intel Core i7-990X has 6 cores and 12 threads. The Intel Xeon E3-1265L v4 has 4 cores and 8 threads. The i7-990X offers more parallel processing capacity.

Q: What are the release dates for these CPUs?

A: The Intel Core i7-990X was released on February 23, 2011. The Intel Xeon E3-1265L v4 was released on June 1, 2015.

Head-to-Head Benchmarks

The six head-to-head benchmark results show a consistent pattern of the Intel Core i7-990X outperforming the Intel Xeon E3-1265L v4 by a narrow margin. The biggest win for the i7-990X is in Cinebench R23 single-core, where it scores 857 against the Xeon's 834, a 2.8% difference. The second-largest margin is in Cinebench R23 multi-core, with 6071 versus 5910, a 2.7% lead. The Cinebench R20 tests show the same 2.7% margin in multi-core (2549 vs 2482) and a 2.6% margin in single-core (359 vs 350).

The Cinebench R15 results follow the same trend. In multi-core, the i7-990X scores 611 against the Xeon's 595, a 2.7% advantage. In single-core, the i7-990X scores 86 against 84, a 2.4% lead, which is the smallest margin of any test. Across all six benchmarks, the i7-990X's smallest winning margin is 2.4% and its largest is 2.8%. The Xeon never wins a test, but its scores are consistently close, falling within 3% of the i7-990X in every category. This tight clustering explains why both processors share the same 40th percentile ranking among all CPUs.

Specification Differences

The specification sheets for these two processors reveal differences in nearly every category. The Intel Core i7-990X uses the Westmere architecture with the Gulftown codename, while the Intel Xeon E3-1265L v4 uses Broadwell with the Broadwell-DT codename. The i7-990X has 6 cores and 12 threads; the Xeon has 4 cores and 8 threads. Base clocks differ significantly: the i7-990X runs at 3.47 GHz, while the Xeon runs at 2.30 GHz. Boost clocks are 3.73 GHz for the i7-990X and 3.30 GHz for the Xeon. The TDP difference is stark: 130 watts for the i7-990X versus 35 watts for the Xeon.

The sockets are incompatible: the i7-990X uses Intel Socket 1366, and the Xeon uses Intel Socket 1150. The process node favors the Xeon at 14 nm versus the i7-990X's 32 nm. The i7-990X has more transistors (1,170 million) and a larger die (239 mm²) compared to the Xeon's 182 mm² die. Cache configurations show 12 MB shared L3 on the i7-990X versus 6 MB shared L3 on the Xeon, with identical 64 KB L1 and 256 KB L2 per core. Memory support differs in channel count: triple-channel for the i7-990X, dual-channel for the Xeon, with the Xeon listing a 29.9 GB/s memory bandwidth. The Xeon supports ECC memory and integrated Intel Iris Pro P6300 graphics; the i7-990X supports neither. The i7-990X has an unlocked multiplier and a part number of SLBVZ, while the Xeon has a locked multiplier and a part number of SR2B3. The Xeon's launch MSRP is $417; the i7-990X has no listed launch MSRP. The Xeon uses PCIe Gen 3 with 16 lanes, while the i7-990X uses PCIe Gen 2.