Intel Core 3 305 vs Intel Core Ultra 5 250KF Plus Comparison

Where Each One Wins

The benchmark data presents an unusually one-sided comparison. Across all 17 recorded head-to-head tests, the Intel Core Ultra 5 250KF Plus takes every single win. The Intel Core 3 305 does not claim victory in any measured workload, which makes this less about identifying complementary strengths and more about quantifying the scale of the Ultra 5's advantage.

The largest gaps appear in heavily multithreaded and data-intensive workloads. The Ultra 5 250KF Plus leads by 73.8% in PassMark integer math and random string sorting, and by 73.5% in data compression and floating-point math. These are workloads that scale with core count, memory bandwidth, and cache capacity, all areas where the Ultra 5 holds substantial physical advantages.

The narrowest margin occurs in single-threaded performance. In PassMark single-thread testing, the Ultra 5 250KF Plus leads by only 15.3%, scoring 4698 against the Core 3 305's 3977. This suggests that while the Ultra 5 dominates in parallel tasks, the Core 3 305's single-core efficiency is comparatively less distant, likely due to its higher boost clock relative to its modest core configuration.

Cinebench results reinforce the same pattern but with even more extreme deltas. The Ultra 5 250KF Plus leads by 69.3% to 69.4% across all Cinebench R15, R20, and R23 tests, whether single-core or multi-core. The consistency of that margin across different Cinebench versions indicates the gap is structural rather than workload-specific.

For PassMark physics, the Ultra 5 leads by 61.3%, the smallest multi-threaded margin recorded. This workload may be more sensitive to per-core efficiency than raw thread count, narrowing the deficit slightly. Still, the Core 3 305 never comes within striking distance in any test.

Architecture Differences

The two processors occupy entirely different market segments and physical designs, which explains the benchmark chasm. The Intel Core 3 305 is a mobile part built for the Intel BGA 1516 socket, while the Intel Core Ultra 5 250KF Plus is a desktop processor using Intel Socket 1851. This alone dictates different power envelopes, cooling solutions, and performance expectations.

Core counts differ dramatically. The Core 3 305 packs 6 cores and 6 threads with no hyper-threading, while the Ultra 5 250KF Plus provides 18 cores and 18 threads. That triple core advantage directly fuels the multi-threaded benchmark landslide. The Ultra 5 also runs a 4.20 GHz base clock and 5.30 GHz boost clock, compared to the Core 3 305's 1.50 GHz base and 4.30 GHz boost. The higher base clock matters for sustained workloads, while the boost clock advantage of 1.00 GHz helps single-thread responsiveness.

Cache hierarchies tell a similar story. The Core 3 305 offers 192 KB L1, 2.5 MB L2, and 6 MB shared L3. The Ultra 5 250KF Plus provides 192 KB L1 per core, 3 MB L2 per core, and 30 MB shared L3. With more cores and vastly more aggregate cache, the Ultra 5 can keep far more working data close to the execution units, reducing memory stalls in data-heavy workloads.

Memory subsystems also diverge. The Core 3 305 supports DDR5 and LPDDR5X with a single-channel memory bus and 59.7 GB/s bandwidth. The Ultra 5 250KF Plus supports DDR5 through a dual-channel bus delivering 115.2 GB/s, nearly double the bandwidth. For compression, encryption, and sorting workloads that move large data volumes, this bandwidth difference compounds with the cache and core advantages.

The process node is nominally the same at 3 nm, but the foundries differ. The Core 3 305 comes from Intel's own fabs under the Wildcat Lake codename, while the Ultra 5 250KF Plus is built by TSMC under the Arrow Lake Refresh codename. The Ultra 5 also carries a transistor count of 17,800 million on a 243 mm² die, whereas the Core 3 305 has no published transistor or die size data.

Integrated graphics separate them further. The Core 3 305 includes Intel Xe3 Graphics with 1 Xe core, making it self-contained for display output. The Ultra 5 250KF Plus has no integrated graphics at all, which explains the "F" in its naming and requires a discrete GPU. ECC memory support also differs: the Ultra 5 supports ECC, the Core 3 305 does not.

PCIe connectivity is another divide. The Core 3 305 offers Gen 4 with 6 CPU lanes, while the Ultra 5 250KF Plus provides Gen 5 with 20 CPU lanes. That affects expansion capability and I/O throughput for storage and add-in cards.

The Verdict

The data points to a clear segmentation. The Intel Core 3 305 serves as a low-power mobile processor where efficiency and integrated graphics matter more than raw throughput. Its 15 W TDP, single-channel memory, and compact BGA socket align with thin-and-light laptops where battery life and thermal limits dominate. The presence of integrated Xe3 graphics means no discrete GPU is required for basic display tasks.

The Intel Core Ultra 5 250KF Plus is a desktop powerhouse aimed at compute-heavy workloads. Its 125 W TDP, dual-channel memory, 18 cores, and 30 MB L3 cache make it suited for rendering, data compression, encryption, and physics simulations. The lack of integrated graphics signals that buyers will pair it with a dedicated GPU, and the unlocked multiplier allows overclocking for those seeking additional performance.

Benchmark percentiles reinforce this split. The Core 3 305 sits at the 72nd percentile among all CPUs, a respectable showing for a mobile chip. The Ultra 5 250KF Plus reaches the 93rd percentile, placing it near the top of the desktop hierarchy. The average benchmark score of 66,159 for the Ultra 5 versus 18,302 for the Core 3 305 quantifies the overall performance gap at roughly 3.6 times.

For a mobile user whose primary concern is battery life and portability, the Core 3 305's data shows it can handle moderate workloads without the power draw of a desktop part. For anyone needing maximum compute throughput in a desktop chassis, the Ultra 5 250KF Plus dominates every measured metric. There is no workload in the recorded data where the Core 3 305 wins, so the choice reduces to form factor and power priorities rather than performance trade-offs.

FAQ

Q: Which processor has more cores?

A: The Intel Core Ultra 5 250KF Plus has 18 cores and 18 threads, while the Intel Core 3 305 has 6 cores and 6 threads.

Q: Does the Intel Core 3 305 include integrated graphics?

A: Yes, it features Intel Xe3 Graphics with 1 Xe core. The Intel Core Ultra 5 250KF Plus has no integrated graphics.

Q: What is the largest performance gap between the two?

A: The largest delta is 74.6% in PassMark find prime numbers, where the Ultra 5 250KF Plus scores 452 against the Core 3 305's 115.

Q: Which chip supports ECC memory?

A: The Intel Core Ultra 5 250KF Plus supports ECC memory. The Intel Core 3 305 does not.

Q: What is the smallest performance margin recorded?

A: The smallest margin is 15.3% in PassMark single-thread testing, where the Ultra 5 250KF Plus scores 4698 versus the Core 3 305's 3977.

Q: How do their memory bandwidth figures compare?

A: The Ultra 5 250KF Plus provides 115.2 GB/s through dual-channel DDR5, while the Core 3 305 offers 59.7 GB/s through single-channel DDR5 or LPDDR5X.

Head-to-Head Benchmarks

The Cinebench R23 multi-core test shows the Ultra 5 250KF Plus scoring 42,718 against the Core 3 305's 13,123, a 69.3% lead. That delta repeats almost exactly in Cinebench R20 multi-core (17,941 versus 5,511) and Cinebench R15 multi-core (4,305 versus 1,322), indicating that the multi-threaded gap is consistent across renderer versions.

Single-core Cinebench results are equally lopsided. In Cinebench R23 single-core, the Ultra 5 scores 6,030 versus 1,852, a 69.3% advantage. Cinebench R20 single-core shows 2,532 versus 777, and Cinebench R15 single-core shows 607 versus 186, both at 69.4%. The near-identical percentages across all three versions suggest the single-core advantage stems from the higher boost clock and newer architecture rather than any test-specific quirk.

PassMark data compression reveals one of the larger gaps: 553,155 for the Ultra 5 against 146,857 for the Core 3 305, a 73.5% lead. Data encryption follows at 41,292 versus 11,019, a 73.3% gap. These workloads benefit directly from the Ultra 5's larger L3 cache and wider memory bus.

The floating-point math test shows 159,824 against 42,284, another 73.5% margin. Integer math runs 123,030 versus 32,295, a 73.8% gap. Extended instructions score 42,880 versus 13,543, a 68.4% lead. Find prime numbers delivers the widest gap at 74.6%, with 452 versus 115.

PassMark multithread measures 50,146 versus 15,439, a 69.2% lead. Random string sorting shows 67,209 versus 17,623, a 73.8% gap. Physics testing narrows to 3,183 versus 1,233, a 61.3% lead, the smallest multi-threaded margin.

PassMark single-thread results are the closest overall: 4,698 versus 3,977, a 15.3% lead. This test appears twice in the data with identical scores, confirming the result. While the Ultra 5 still wins clearly, this 15.3% gap is far smaller than the 60% to 75% margins seen elsewhere, suggesting that per-core efficiency is the Core 3 305's least distant metric.

Specification Differences

The two processors diverge on nearly every hardware specification. Core counts: 6 versus 18. Threads: 6 versus 18. Base clock: 1.50 GHz versus 4.20 GHz. Boost clock: 4.30 GHz versus 5.30 GHz. TDP: 15 W versus 125 W.

Socket types differ completely: Intel BGA 1516 for the Core 3 305, Intel Socket 1851 for the Ultra 5 250KF Plus. The Core 3 305 uses a mobile form factor, while the Ultra 5 is a desktop part. Their codenames are Wildcat Lake and Arrow Lake Refresh respectively, with the Ultra 5 belonging to the Core Ultra Series 2.

Process nodes are both 3 nm, but the foundries differ: Intel for the Core 3 305, TSMC for the Ultra 5 250KF Plus. The Ultra 5 lists 17,800 million transistors on a 243 mm² die; the Core 3 305 has no transistor or die size data.

Cache configurations are not directly comparable. The Core 3 305 has 192 KB L1, 2.5 MB L2, and 6 MB shared L3. The Ultra 5 250KF Plus has 192 KB L1 per core, 3 MB L2 per core, and 30 MB shared L3. The per-core L2 allocation on the Ultra 5 means its aggregate L2 scales with core count.

Memory support varies: DDR5 and LPDDR5X for the Core 3 305, DDR5 only for the Ultra 5. Memory bus is single-channel versus dual-channel. Memory bandwidth is 59.7 GB/s versus 115.2 GB/s. ECC memory is unsupported on the Core 3 305 and supported on the Ultra 5.

PCIe lanes differ: Gen 4 with 6 CPU lanes for the Core 3 305, Gen 5 with 20 CPU lanes for the Ultra 5. Integrated graphics are present on the Core 3 305 (Intel Xe3 Graphics, 1 Xe core) and absent on the Ultra 5. The multiplier is locked on the Core 3 305 and unlocked on the Ultra 5.

Release dates are 2026-04-15 for the Core 3 305 and 2026-03-10 for the Ultra 5 250KF Plus, with both marked as active in production. The launch MSRP for the Core 3 305 is $309, while the Ultra 5 250KF Plus has a launch MSRP of $184. Part numbers are SAE3L and SA4V3 respectively.