Intel Core i9-9940X vs Intel Xeon W-2191B Comparison

FAQ

Q: Which CPU has more cores and threads?

A: The Intel Xeon W-2191B packs 18 cores and 36 threads, while the Intel Core i9-9940X has 14 cores and 28 threads. That is a four-core, eight-thread advantage for the Xeon.

Q: How do they compare in multi-core rendering workloads?

A: In Cinebench R23 multi-core, the Xeon W-2191B scores 23887 versus 23810 for the i9-9940X — a 0.3% edge. The gap is similarly tiny in Cinebench R20 (10032 vs 10000) and R15 (2407 vs 2400). The Xeon wins all six Cinebench tests, but by margins under half a percent.

Q: Where does the Core i9-9940X pull ahead?

A: The i9-9940X wins decisively in Geekbench. It scores 10466 in multi-core versus 9614 for the Xeon (8.1% higher), and 1468 in single-core versus 1182 (19.5% higher). These are the only two benchmark wins for the i9, but they are substantial.

Q: Do both CPUs use the same socket and memory configuration?

A: Yes, both fit the Intel Socket 2066 and support DDR4 memory in quad-channel mode with an identical 85.3 GB/s memory bandwidth. The Xeon W-2191B supports ECC memory; the Core i9-9940X does not.

Q: What about PCIe lanes?

A: The Xeon W-2191B provides 48 PCIe Gen 3 lanes (CPU only), while the Core i9-9940X provides 44. That is a four-lane difference, which can matter for heavily populated workstation boards.

Q: Is the Core i9-9940X overclockable?

A: Yes, the i9-9940X has an unlocked multiplier. The Xeon W-2191B is locked. The i9 also has a higher base clock (3.30 GHz vs 2.30 GHz) and a higher boost clock (4.50 GHz vs 4.30 GHz).

The Verdict

The benchmark data paints a clear picture: these two CPUs are nearly identical in raw compute performance, but they target different buyers. The Xeon W-2191B takes six of eight head-to-head tests, yet its wins are marginal — every Cinebench victory is between 0.3% and 0.4%. The i9-9940X, despite losing most tests, wins the two Geekbench results by 8.1% and 19.5%, which are far larger margins.

For a workstation builder who needs ECC memory support, 48 PCIe lanes, and maximum multi-threaded rendering consistency, the Xeon W-2191B is the logical choice. Its 18 cores and 36 threads give it a structural advantage in heavily threaded workloads, and the data confirms it edges out the i9 in every Cinebench run. The server/workstation market segment and locked multiplier are acceptable trade-offs when stability and memory integrity matter more than tuning.

For a desktop enthusiast who prioritizes single-core speed and overclocking headroom, the Core i9-9940X is the pick. Its 19.5% lead in Geekbench single-core is the largest performance gap in this entire comparison. The unlocked multiplier, higher clocks (3.30 GHz base, 4.50 GHz boost), and 165W TDP suggest it is built for flexibility. The 14-core/28-thread count is lower, but the Geekbench multi-core win shows it can still handle parallel loads effectively.

The average benchmark scores reflect this split: the i9-9940X averages 6657 versus 6531 for the Xeon, a difference of roughly 1.9%. Both sit at the 62nd percentile among all CPUs. Neither is a dominant winner. If you need ECC and lane count, take the Xeon. If you want speed per thread and the ability to overclock, take the i9.

Head-to-Head Benchmarks

The six Cinebench tests all go to the Xeon W-2191B, but the margins are almost laughably small. In Cinebench R15 multi-core, the Xeon scores 2407 against 2400 for the i9 — a 0.3% delta. Single-core R15 is 339 versus 338, again 0.3%. Moving to R20, the Xeon posts 10032 multi-core and 1416 single-core, versus 10000 and 1411 for the i9. The deltas are 0.3% and 0.4%, respectively. R23 shows the same pattern: 23887 multi-core and 3372 single-core for the Xeon, versus 23810 and 3361 for the i9, both 0.3% gaps.

The Geekbench results flip the script entirely. In multi-core, the i9-9940X scores 10466 versus 9614 for the Xeon, an 8.1% advantage. Single-core is even more lopsided: 1468 versus 1182, a 19.5% lead for the i9. That single-core delta is the single biggest margin in any test, and it dwarfs the combined Cinebench edges.

What does this mean practically? In sustained multi-threaded rendering, the Xeon is marginally faster — you would need a very long render to notice 0.3%. But in bursty, latency-sensitive single-threaded tasks, the i9 is noticeably quicker. The Geekbench multi-core result also suggests the i9's higher clocks help it in workloads that don't scale perfectly with core count. The Xeon's four extra cores do not translate into a meaningful win outside Cinebench's scaling model.

Specification Differences

The two CPUs share the same socket, memory type, memory bus width, memory bandwidth, process node, foundry, die size, L1 cache (64 KB per core), and L2 cache (1 MB per core). That is where the similarities end.

• Cores: Xeon W-2191B has 18, i9-9940X has 14.
• Threads: Xeon has 36, i9 has 28.
• Base Clock: Xeon 2.30 GHz, i9 3.30 GHz.
• Boost Clock: Xeon 4.30 GHz, i9 4.50 GHz.
• TDP: Xeon 140W, i9 165W.
• L3 Cache: Xeon 24.75 MB shared, i9 19.25 MB shared.
• ECC Memory: Xeon supports it, i9 does not.
• PCIe Lanes: Xeon 48, i9 44.
• Market Segment: Xeon is Server/Workstation, i9 is Desktop.
• Release Date: Xeon December 2017, i9 October 2018.
• Unlocked Multiplier: Xeon no, i9 yes.
• Part Number: Xeon SR3RW, i9 SREZ5.

The i9 also has a launch MSRP of $1387. The Xeon has no listed launch MSRP.

Architecture Differences

Both processors are built on Intel's 14nm Skylake architecture, and both use the same 484 mm² die. The codenames differ — Skylake-W for the Xeon, Skylake-X for the i9 — but the underlying silicon is the same generation. The Xeon is designated as part of the Xeon W (Skylake-W) family, while the i9 is part of the Core i9 X-Series 9th Gen lineup.

The core count difference (18 vs 14) is the primary architectural distinction. The Xeon's larger 24.75 MB L3 cache versus 19.25 MB on the i9 reflects that extra silicon. Both have identical per-core L1 and L2 caches, so the delta is purely in the shared L3 pool.

Feature support diverges in two notable areas. The Xeon W-2191B enables ECC memory, which is a hallmark of workstation reliability. The i9-9940X lacks ECC support entirely. The Xeon also exposes 48 PCIe Gen 3 lanes versus 44 on the i9, giving it more headroom for expansion cards, NVMe drives, or GPU clusters.

Clock behavior is a function of market positioning. The i9 starts at 3.30 GHz base and boosts to 4.50 GHz, while the Xeon starts lower at 2.30 GHz and boosts to 4.30 GHz. The i9's higher TDP (165W vs 140W) is the cost of those clocks. The unlocked multiplier on the i9 means users can push beyond stock boost behavior, whereas the Xeon is locked to its factory settings.

Where Each One Wins

The Xeon W-2191B wins in:

• Multi-threaded rendering: It takes all three Cinebench multi-core tests (R15, R20, R23) with 2407, 10032, and 23887 points respectively. The margins are tiny, but they are consistent.
• Single-threaded rendering: It also wins all three Cinebench single-core tests (339, 1416, 3372) by 0.3-0.4%. If your application uses Cinebench's rendering engine, the Xeon is the safer bet.
• Workstation reliability: ECC memory support and 48 PCIe lanes make it the better fit for servers or workstations where data integrity and I/O expansion are critical. The 18-core/36-thread configuration gives it more parallel headroom for heavily threaded server workloads.
• Power efficiency: The Xeon delivers nearly identical Cinebench performance at a 140W TDP versus 165W for the i9, a 25W difference.

The Core i9-9940X wins in:

• Geekbench multi-core: 10466 versus 9614, an 8.1% lead. This suggests better performance in applications that use Geekbench's workload mix, which tends to favor higher clocks over raw core counts.
• Geekbench single-core: 1468 versus 1182, a 19.5% lead. This is the largest gap in the entire comparison. For everyday responsiveness, web browsing, or lightly threaded applications, the i9 is noticeably faster.
• Overclocking: The unlocked multiplier plus higher base and boost clocks (3.30/4.50 GHz) give enthusiasts room to push performance further. The Xeon is locked.
• Desktop flexibility: The i9's desktop market segment and lower core count (14) mean it is designed for consumer workloads, not server duty. Its higher average benchmark score (6657 vs 6531) reflects this.

The practical split: If you are building a render farm node or a workstation that must run 24/7 with ECC memory, take the Xeon W-2191B. If you are building a high-end desktop for mixed use — gaming, content creation, and general productivity — the i9-9940X offers better single-threaded performance and overclocking freedom. The data does not support a universal winner; it supports two different tools for two different jobs.