Intel Core i7-990X vs Intel Xeon D-1528 Comparison

FAQ

Q: Which processor wins the most head-to-head benchmarks in the database?

A: The Intel Core i7-990X wins all six recorded head-to-head tests against the Xeon D-1528. Its margins range from 4.6% to 4.9% across Cinebench R15, R20, and R23, covering both single-core and multi-core workloads.

Q: How do their average benchmark scores compare?

A: The i7-990X has an average benchmark score of 1713, while the Xeon D-1528 sits at 1677. That is a difference of roughly 2% in favor of the desktop part, and both processors land in the 40th percentile of all CPUs in the database.

Q: What is the biggest single-core advantage in the head-to-head results?

A: The largest single-core margin is in Cinebench R15, where the i7-990X scores 86 against the Xeon D-1528's 82, a 4.9% advantage. The R20 and R23 single-core tests show similar gaps at 4.7% and 4.8%, respectively.

Q: Does the Xeon D-1528 have any architectural advantages over the i7-990X?

A: Yes. The Xeon D-1528 is built on a 14 nm process (versus 32 nm for the i7-990X), supports DDR3 and DDR4 memory, includes ECC memory support, and uses PCIe Gen 3 with 24 lanes. The i7-990X is limited to DDR3, has no ECC support, and uses PCIe Gen 2.

Q: Are both processors identical in core and thread counts?

A: Yes. Both have 6 cores and 12 threads. Their L1 and L2 caches are also identical at 64 KB per core and 256 KB per core, respectively. The key cache difference is in L3: the i7-990X has 12 MB shared, while the Xeon D-1528 has 1.5 MB per core.

Q: Which processor has the lower TDP?

A: The Xeon D-1528 has a TDP of 35, compared to 130 for the i7-990X. This is a substantial difference, making the Xeon D-1528 far more suitable for dense, power-constrained server environments.

Architecture Differences

The Intel Core i7-990X is a Gulftown-based Westmere part, released in February 2011 on the Intel Socket 1366 platform. It uses a 32 nm process with 1,170 million transistors on a 239 mm² die. The Xeon D-1528, released in October 2015, is a Broadwell-DE part on Intel BGA 1667, built on a 14 nm process with 3,200 million transistors on a 246 mm² die. The process shrink is significant: the Xeon D-1528 packs nearly three times as many transistors into a slightly larger die, which reflects the newer design's integrated platform features.

Both CPUs share the same core and thread counts (6 cores, 12 threads) and the same L1 and L2 cache layout (64 KB and 256 KB per core). The L3 cache differs in organization: the i7-990X uses a 12 MB shared pool, while the Xeon D-1528 allocates 1.5 MB per core. For a 6-core chip, that works out to 9 MB total in the Xeon, but the per-core partitioning changes how the cache is accessed under load.

Memory support also diverges. The i7-990X uses triple-channel DDR3, which historically gave it a bandwidth advantage on its platform. The Xeon D-1528 uses dual-channel DDR3 or DDR4, and it adds ECC memory support, a staple for server reliability. PCIe generations differ as well: the i7-990X is Gen 2, while the Xeon D-1528 offers Gen 3 with 24 lanes from the CPU.

The Xeon D-1528 is a server/workstation part with a locked multiplier, while the i7-990X is a desktop Extreme edition with an unlocked multiplier. The i7-990X is end-of-life, whereas the Xeon D-1528 remains active in production. The Xeon also has a launch MSRP of $320, which is noted here once.

Head-to-Head Benchmarks

The database records six head-to-head comparisons, all favoring the i7-990X. The smallest margin is 4.6% in Cinebench R15 multi-core, where the i7-990X scores 611 and the Xeon D-1528 scores 584. In the same test's single-core variant, the i7-990X leads by 4.9% (86 versus 82). That single-core gap is the largest of any recorded test.

Moving to Cinebench R20, the multi-core result shows the i7-990X at 2549 against 2435 for the Xeon, a 4.7% lead. The single-core R20 result is identical in percentage: 359 versus 343, again 4.7%. In Cinebench R23, the multi-core score is 6071 for the i7-990X and 5799 for the Xeon D-1528, a 4.7% margin. The R23 single-core test shows 857 versus 818, a 4.8% advantage.

Across all tests, the i7-990X's advantage is remarkably consistent, hovering between 4.6% and 4.9%. This consistency suggests the performance gap is not workload-specific but rather a uniform clock-speed and architecture efficiency difference. The i7-990X operates at a base clock of 3.47 GHz and boosts to 3.73 GHz, while the Xeon D-1528 runs at 1.90 GHz base and 2.50 GHz boost. The desktop chip's higher clocks directly translate into its consistent lead in both single-threaded and multi-threaded Cinebench runs.

The Xeon D-1528 does not win a single recorded head-to-head test. Its best showing is in R15 multi-core, where it trails by only 4.6%, but it never closes the gap below that threshold.

Specification Differences

| Specification | Intel Core i7-990X | Intel Xeon D-1528 |

| --- | --- | --- |

| Base Clock | 3.47 GHz | 1.90 GHz |

| Boost Clock | 3.73 GHz | 2.50 GHz |

| TDP | 130 | 35 |

| Socket | Intel Socket 1366 | Intel BGA 1667 |

| Process Node | 32 nm | 14 nm |

| Transistors | 1,170 million | 3,200 million |

| Die Size | 239 mm² | 246 mm² |

| L3 Cache | 12 MB (shared) | 1.5 MB (per core) |

| Memory Support | DDR3 | DDR3, DDR4 |

| Memory Bus | Triple-channel | Dual-channel |

| ECC Memory | No | Yes |

| PCIe | Gen 2 | Gen 3, 24 Lanes (CPU only) |

| Market Segment | Desktop | Server/Workstation |

| Production Status | End-of-life | Active |

| Release Date | 2011-02-23 | 2015-10-31 |

| Multiplier Unlocked | Yes | No |

| Part Number | SLBVZ | SR2DL |

The two chips share identical core counts, thread counts, L1 cache, and L2 cache. They also share the same manufacturer and foundry. Everything else on the specification sheet differs, from clock speeds to memory channels to platform support.

Where Each One Wins

The Intel Core i7-990X wins in every performance benchmark recorded in the database. Its advantages are most pronounced in single-core workloads, where higher clock speeds matter most. With a base clock of 3.47 GHz and boost of 3.73 GHz, it outruns the Xeon D-1528 by roughly 5% in single-threaded Cinebench tests. For users running older desktop software that relies on high per-core performance, the i7-990X is the clear choice.

The i7-990X also wins in multi-core scenarios, though by a slightly smaller margin. In Cinebench R15, R20, and R23 multi-core tests, it leads by 4.6% to 4.7%. This is notable because both chips have the same core and thread counts, so the i7-990X's edge comes entirely from its clock speed advantage and its shared 12 MB L3 cache.

The Xeon D-1528 wins in areas that are not covered by Cinebench but are critical for server deployments. It supports ECC memory, which the i7-990X does not. It runs on DDR3 and DDR4, offering more modern memory options. It uses PCIe Gen 3, doubling the bandwidth of the i7-990X's Gen 2. Its 35 TDP is dramatically lower than 130, which makes it viable for passively cooled or low-power server chassis. The Xeon's active production status also means it remains available for new system builds, while the i7-990X is end-of-life.

The Verdict

The performance data is unambiguous: the Intel Core i7-990X is the faster CPU in every recorded benchmark. Across six Cinebench tests, it wins by margins between 4.6% and 4.9%. If the selection criteria are raw compute performance in single-threaded or multi-threaded workloads, the i7-990X is the better part.

The Xeon D-1528, however, is not a failed product. It trades a modest performance deficit for a massive reduction in power draw, with a 35 TDP versus 130. It adds ECC memory, DDR4 support, and PCIe Gen 3, all of which matter in server environments where data integrity and platform longevity take priority over peak benchmark scores. The Xeon is also still in active production, whereas the i7-990X has been discontinued.

For a desktop enthusiast building a legacy Socket 1366 system with an unlocked multiplier, the i7-990X offers the best recorded performance. For a server or workstation deployment where ECC, low power, and modern PCIe are required, the Xeon D-1528 is the appropriate choice despite losing every Cinebench comparison. The database cannot say one is universally better; it can only say the i7-990X is faster and the Xeon D-1528 is more efficient and server-oriented. Buyers should decide based on their platform needs, not on raw score alone.