Intel Core Ultra 5 250KF Plus vs Intel Core Ultra 7 266V Comparison

The Verdict

The benchmark data presents a decisive split between these two Intel Core Ultra Series 2 processors. The Intel Core Ultra 5 250KF Plus wins every single head-to-head benchmark in the database, taking all 17 recorded comparisons. Its average benchmark score of 66159 places it at the 93rd percentile of all CPUs, while the Intel Core Ultra 7 266V averages 23297, sitting at the 76th percentile.

The Core Ultra 5 250KF Plus is the clear choice for desktop builders who need heavy multithreaded throughput. It delivers more than double the multi-core performance of the 266V in every Cinebench test, with deltas consistently around 158%. The PassMark suite shows even larger gaps in specific workloads, such as a 198.7% lead in data encryption and a 196% lead in integer math. Its nearest rivals include the AMD Ryzen 9 7950X3D, which trails by only 0.4%, and the Intel Core Ultra 5 250K Plus, which leads by 1%. This places it firmly in high-end desktop territory.

The Core Ultra 7 266V serves a different purpose entirely. As a mobile part with a 17W TDP, it trades throughput for efficiency. Its nearest rivals are the AMD Ryzen 7 5800H (0.1% behind) and the Intel Core i9-11900F (0.2% behind), which shows it competes with older mainstream desktop chips rather than modern flagship parts. The single-thread gap is much smaller than the multi-thread gap: the 250KF Plus leads by only 19.1% in PassMark single-thread, compared to 158.2% in Cinebench R23 multi-core. For users constrained by power and physical space, the 266V is the appropriate pick; for anyone building a desktop where performance is the priority, the 250KF Plus wins without qualification.

Architecture Differences

Both processors share the same 3 nm TSMC process node and belong to Intel's Core Ultra Series 2 family, but their architectures diverge sharply. The Core Ultra 5 250KF Plus uses the Arrow Lake Refresh architecture, while the Core Ultra 7 266V uses Lunar Lake. The 250KF Plus has 18 cores and 18 threads, all of equal nature with no hyperthreading. The 266V has 8 cores and 8 threads. This core count disparity is the primary driver of the multi-core benchmark results.

Cache organization also differs. The 250KF Plus allocates 192 KB of L1 per core, 3 MB of L2 per core, and 30 MB of shared L3 cache. The 266V matches the 192 KB L1 per core, but drops to 2.5 MB of L2 per core and only 12 MB of shared L3. Transistor counts and die sizes are recorded for the 250KF Plus (17,800 million transistors on a 243 mm² die) but are not available for the 266V.

The memory controllers reflect their different market segments. The 250KF Plus supports DDR5 over a dual-channel bus with 115.2 GB/s of bandwidth and includes ECC memory support. The 266V uses LPDDR5X, which depends on the motherboard, over a dual-channel bus with higher bandwidth at 136.5 GB/s, but lacks ECC support. PCIe connectivity differs substantially: the 250KF Plus provides Gen 5 with 20 CPU lanes, while the 266V offers Gen 5 with just 4 CPU lanes.

Integrated graphics separate the two as well. The 250KF Plus has no integrated graphics (N/A), which explains its "KF" designation. The 266V includes Arc 140V graphics, making it a complete mobile solution without a discrete GPU. The 250KF Plus has an unlocked multiplier for overclocking, while the 266V is locked. Sockets differ completely: the 250KF Plus uses Intel Socket 1851 for desktop, while the 266V uses Intel BGA 2833, a soldered mobile package.

Where Each One Wins

The Core Ultra 5 250KF Plus wins in every recorded workload category, but the size of its advantage varies by workload type. The largest leads appear in data-heavy PassMark tasks. Data encryption shows a 198.7% lead, integer math a 196% lead, and data compression a 195.7% lead. Random string sorting trails closely at 193.4%. These workloads scale with core count and memory bandwidth, areas where the 18-core desktop part dominates.

Floating-point math shows a 180.8% lead, and extended instructions (SIMD-style workloads) show a 169.2% lead. Prime number finding, a latency-sensitive integer workload, shows the smallest multi-thread gap among PassMark tests at 136.6%. Physics simulation shows a 97.9% lead, the smallest advantage in the entire benchmark set aside from single-thread tests. This suggests the 266V's Lunar Lake cores are relatively competitive in latency-bound scalar workloads, though still far behind.

The single-thread tests reveal the closest contest. PassMark single-thread scores are 4698 for the 250KF Plus versus 3943 for the 266V, a 19.1% lead. Cinebench single-core tests show a larger gap (158.3% in R15, 158.4% in R20, 158.2% in R23), but those scores reflect the much higher boost clock and desktop power envelope of the 250KF Plus. The 266V still delivers respectable single-thread performance for a 17W part, landing within one-fifth of the desktop chip in PassMark's single-thread test.

The 266V wins on efficiency and integration. Its 17W TDP against 125W for the 250KF Plus makes it suitable for thin-and-light laptops. The integrated Arc 140V graphics eliminate the need for a separate GPU. The higher memory bandwidth (136.5 GB/s versus 115.2 GB/s) suggests the mobile part is optimized for memory-bound tasks within its power budget, though its raw scores remain far lower.

FAQ

Q: Which processor has better multi-core performance?

A: The Intel Core Ultra 5 250KF Plus dominates. In Cinebench R23 multi-core, it scores 42718 against 16544 for the 266V, a 158.2% lead. The same margin repeats across R15 and R20 multi-core tests.

Q: How close is single-thread performance?

A: The 250KF Plus leads in all single-thread tests, but the margin varies. PassMark single-thread shows 4698 versus 3943, a 19.1% lead. Cinebench R23 single-core shows 6030 versus 2335, a 158.2% lead.

Q: Does the Core Ultra 7 266V have integrated graphics?

A: Yes, it includes Arc 140V integrated graphics. The Core Ultra 5 250KF Plus has no integrated graphics at all, marked as N/A in the database.

Q: Are both processors unlocked for overclocking?

A: No. The 250KF Plus has an unlocked multiplier, while the 266V is locked. The 266V is a mobile BGA part, which also prevents overclocking by design.

Q: What memory types do these processors support?

A: The 250KF Plus supports DDR5 with ECC memory support. The 266V supports LPDDR5X, which depends on the motherboard, and does not support ECC memory.

Q: How do their average benchmark scores compare?

A: The 250KF Plus has an average benchmark score of 66159, placing it at the 93rd percentile of all CPUs. The 266V averages 23297, placing it at the 76th percentile.

Head-to-Head Benchmarks

The Cinebench suite shows a consistent pattern across every test. Cinebench R15 multi-core scores 4305 for the 250KF Plus against 1667 for the 266V, a 158.2% lead. R15 single-core shows 607 versus 235, a 158.3% lead. R20 multi-core delivers 17941 versus 6948, again 158.2%. R20 single-core shows 2532 versus 980, the largest Cinebench delta at 158.4%. R23 multi-core records 42718 versus 16544, and R23 single-core records 6030 versus 2335, both at 158.2%.

The PassMark suite amplifies the desktop part's advantages in throughput-heavy tasks. Data compression scores 553155 versus 187050, a 195.7% lead. Data encryption scores 41292 versus 13822, a 198.7% lead, the largest gap in the entire comparison. Extended instructions show 42880 versus 15928, a 169.2% lead. Prime number finding shows 452 versus 191, a 136.6% lead. Floating-point math scores 159824 versus 56923, an 180.8% lead. Integer math scores 123030 versus 41558, a 196% lead.

Multithread workloads follow the same trend. PassMark multithread scores 50146 versus 19461, a 157.7% lead. Random string sorting scores 67209 versus 22905, a 193.4% lead. Physics shows the smallest multi-thread gap at 3183 versus 1608, a 97.9% lead. The single-thread tests close the gap considerably: PassMark single-thread scores 4698 versus 3943, a 19.1% lead, recorded identically in both passmark_single_thread and passmark_singlethread entries.

The database records all 17 head-to-head wins for the 250KF Plus, with zero wins for the 266V. The average score gap is substantial: 66159 versus 23297, a difference of roughly 2.84 times. The 250KF Plus sits among competitors like the AMD Ryzen 9 7950X3D and Intel Core 9 273PQE, both within 0.4% of its average score. The 266V competes with the AMD Ryzen 7 5800H and Intel Core i9-11900F, both within 0.2%. These nearest-rival comparisons confirm that the two chips target completely different performance tiers despite sharing the same series name.

Specification Differences

The core and thread counts differ dramatically: 18 cores and 18 threads for the 250KF Plus against 8 cores and 8 threads for the 266V. Base clocks are 4.20 GHz versus 2.20 GHz, and boost clocks are 5.30 GHz versus 5.00 GHz. The TDP ratings reflect their different sockets and cooling environments: 125W for the desktop part, 17W for the mobile part.

Cache configurations differ in L2 and L3. Both use 192 KB of L1 per core. The 250KF Plus has 3 MB of L2 per core and 30 MB of shared L3. The 266V has 2.5 MB of L2 per core and 12 MB of shared L3. Transistor count and die size are recorded only for the 250KF Plus: 17,800 million transistors on a 243 mm² die.

Memory support differs by type and capability. The 250KF Plus uses DDR5 with ECC support and 115.2 GB/s bandwidth. The 266V uses LPDDR5X (dependent on motherboard) without ECC support and 136.5 GB/s bandwidth. PCIe lanes differ substantially: 20 Gen 5 lanes for the 250KF Plus versus 4 Gen 5 lanes for the 266V.

Integrated graphics, socket, and overclocking all separate the two. The 250KF Plus has no integrated graphics, uses Intel Socket 1851, and has an unlocked multiplier. The 266V includes Arc 140V graphics, uses Intel BGA 2833, and has a locked multiplier. The market segments are recorded as Desktop for the 250KF Plus and Mobile for the 266V. Release dates differ: 2026-03-10 for the 250KF Plus and 2024-09-23 for the 266V. The launch MSRP for the 250KF Plus is $184; no launch MSRP is recorded for the 266V.