Intel Core 3 305 vs Intel Core Ultra 7 265K Comparison

Intel Core 3 305 and Intel Core Ultra 7 265K occupy opposite ends of Intel’s current lineup, and the benchmark data reflects that gap clearly. The Core 3 305 is a 6-thread mobile processor built for efficiency, while the Core Ultra 7 265K is a 20-thread desktop flagship with a 5.50 GHz boost clock. Across every recorded test, the Ultra 7 265K posts a higher score, but the margin varies dramatically by workload. The Core 3 305 holds its own in single-threaded tasks, while the Ultra 7 265K dominates multi-threaded and compute-heavy scenarios.

Where Each One Wins

The Core Ultra 7 265K wins every head-to-head benchmark in the database, but the size of its advantage tells the real story. In Cinebench R23 multi-core, the Ultra 7 265K scores 35,850 against 13,123 for the Core 3 305, a 63.4% lead. That gap widens in Cinebench R15 multi-core, where the Ultra 7 265K scores 5,020 versus 1,322, a 73.7% advantage. This is the pattern for every multi-threaded workload: PassMark multi-thread shows 58,594 against 15,439, a 73.7% gap, and PassMark integer math shows 143,242 versus 32,295, a 77.5% lead. The Ultra 7 265K also dominates data compression, scoring 665,554 against 146,857, a 77.9% advantage, and floating-point math, 189,629 versus 42,284, a 77.7% lead.

The Core 3 305 does not win any test, but its closest competition appears in single-threaded workloads. In Cinebench R23 single-core, the Ultra 7 265K scores 2,020 versus 1,852, a lead of just 8.3%. PassMark single-thread shows 4,928 against 3,977, a 19.3% gap. These are the smallest deltas in the entire comparison, indicating that the Core 3 305’s architecture scales well for lightly threaded tasks despite its lower core count. The Core 3 305 also trails by 67% in PassMark physics (1,233 versus 3,731) and by 75.1% in extended instructions (13,543 versus 54,333), showing that its efficiency focus does not translate to compute-heavy workloads.

Architecture Differences

The two processors share a 3 nm process node but use different foundries and designs. The Core 3 305 uses Intel’s Wildcat Lake architecture with 6 cores and 6 threads, a base clock of 1.50 GHz and a boost clock of 4.30 GHz. It draws 15 W TDP and uses the Intel BGA 1516 socket, marking it as a mobile part. The Ultra 7 265K uses Arrow Lake-S architecture with 20 cores and 20 threads, a base clock of 3.90 GHz and a boost clock of 5.50 GHz. It draws 125 W TDP and uses the Intel Socket 1851, a desktop platform. The Ultra 7 265K is built by TSMC, while the Core 3 305 is built by Intel.

Cache configurations diverge sharply. The Core 3 305 has 192 KB of L1 cache, 2.5 MB of L2 cache, and 6 MB of shared L3 cache. The Ultra 7 265K has 192 KB of L1 cache per core, 3 MB of L2 cache per core, and 30 MB of shared L3 cache. The Ultra 7 265K’s larger cache hierarchy feeds its 20 cores, which explains its multi-threaded dominance. The Core 3 305’s smaller cache totals are appropriate for a 6-thread mobile processor.

Memory and I/O also differ. The Core 3 305 supports DDR5 and LPDDR5X memory over a single-channel bus with 59.7 GB/s bandwidth. The Ultra 7 265K supports DDR5 over a dual-channel bus with 102.4 GB/s bandwidth. The Ultra 7 265K also supports ECC memory, while the Core 3 305 does not. PCIe lanes favor the desktop part: the Ultra 7 265K provides Gen 5 with 20 lanes, while the Core 3 305 provides Gen 4 with 6 lanes. Integrated graphics differ as well, with the Core 3 305 using Intel Xe3 Graphics with 1 Xe and the Ultra 7 265K using Arc Xe-LPG Graphics with 64 EU. The Ultra 7 265K has an unlocked multiplier, while the Core 3 305 does not.

The Verdict

The data points to a clear split. The Core Ultra 7 265K is the choice for workloads that use many threads: rendering, encryption, compression, and math-heavy tasks. Its 20 cores and 30 MB of L3 cache produce leads of 63.4% to 77.9% across Cinebench and PassMark multi-threaded tests. It also holds a smaller but consistent advantage in single-threaded tests, 8.3% in Cinebench R23 single-core and 19.3% in PassMark single-thread. The Ultra 7 265K sits at the 94th percentile of all CPUs in the database, with an average benchmark score of 70,879, and its nearest rivals include the Intel Xeon 6511P and Intel Core i7-14700KF.

The Core 3 305 is a mobile processor with a 15 W TDP, a 72nd percentile ranking, and an average benchmark score of 18,302. It trails the Ultra 7 265K in every test, but its single-threaded performance is relatively close, within 8.3% in Cinebench R23 single-core. Its nearest rivals are the Intel Core i3-14100 and Intel Core 5 330, both of which score within 0.2% of it. The Core 3 305 is not a competitor to the Ultra 7 265K in raw performance; it is a low-power part for portable systems where efficiency matters more than throughput. The database shows no test where the Core 3 305 wins, so the choice is between the Ultra 7 265K’s overwhelming multi-threaded power and the Core 3 305’s mobile efficiency profile.

FAQ

Q: Which processor has more cores?

A: The Intel Core Ultra 7 265K has 20 cores and 20 threads, while the Intel Core 3 305 has 6 cores and 6 threads.

Q: How much faster is the Core Ultra 7 265K in Cinebench R23 multi-core?

A: The Core Ultra 7 265K scores 35,850, which is 63.4% ahead of the Core 3 305’s 13,123.

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

A: The smallest gap is in Cinebench R23 single-core, where the Core Ultra 7 265K leads by 8.3% (2,020 versus 1,852).

Q: Do both processors support ECC memory?

A: No. The Core Ultra 7 265K supports ECC memory, while the Core 3 305 does not.

Q: What memory bandwidth does each processor provide?

A: The Core Ultra 7 265K provides 102.4 GB/s over a dual-channel bus, while the Core 3 305 provides 59.7 GB/s over a single-channel bus.

Q: Which processor has a higher boost clock?

A: The Core Ultra 7 265K has a boost clock of 5.50 GHz, compared to 4.30 GHz for the Core 3 305.

Head-to-Head Benchmarks

The largest margins belong to data-heavy and math-heavy workloads. PassMark data compression shows the Ultra 7 265K scoring 665,554 against 146,857, a 77.9% lead. PassMark random string sorting shows the same 77.9% gap, with scores of 79,752 and 17,623. PassMark data encryption shows 48,246 versus 11,019, a 77.2% lead. PassMark floating-point math shows 189,629 versus 42,284, a 77.7% gap, and PassMark integer math shows 143,242 versus 32,295, a 77.5% lead. PassMark find prime numbers shows 491 versus 115, a 76.6% gap. These results confirm that the Ultra 7 265K’s 20 cores deliver massive throughput advantages in parallel workloads.

Cinebench results follow the same pattern. Cinebench R15 multi-core shows 5,020 versus 1,322, a 73.7% lead, and Cinebench R20 multi-core shows 20,918 versus 5,511, also a 73.7% gap. Cinebench R23 multi-core shows a slightly smaller 63.4% lead, with 35,850 versus 13,123. PassMark multi-thread shows 58,594 versus 15,439, a 73.7% gap, and PassMark physics shows 3,731 versus 1,233, a 67% lead. The Ultra 7 265K’s 20 threads drive consistent 63% to 74% advantages across rendering and physics tests.

Single-threaded tests show a much closer contest. Cinebench R23 single-core gives the Ultra 7 265K a 2,020 to 1,852 win, an 8.3% margin. PassMark single-thread shows 4,928 versus 3,977, a 19.3% gap. Cinebench R15 single-core and Cinebench R20 single-core both show 73.7% leads for the Ultra 7 265K, with scores of 708 versus 186 and 2,953 versus 777 respectively. The Core 3 305’s 4.30 GHz boost clock and 6 threads keep it competitive in lightly threaded tasks, but the Ultra 7 265K’s higher 5.50 GHz boost clock still wins every single-threaded test.

The Ultra 7 265K also wins extended instructions, scoring 54,333 against 13,543, a 75.1% lead. This completes a sweep of all 17 head-to-head benchmarks in the database. The Core 3 305 has zero wins, while the Ultra 7 265K has 17. The percentile rankings reinforce the performance gap: the Ultra 7 265K sits at the 94th percentile of all CPUs, while the Core 3 305 sits at the 72nd percentile. The average benchmark scores are 70,879 for the Ultra 7 265K and 18,302 for the Core 3 305, a difference of 52,577 points.