Intel Core 7 251E vs Intel Core Ultra 7 265K Comparison

Head-to-Head Benchmarks

The comparative data for these two processors is one-sided. The Intel Core Ultra 7 265K holds every recorded benchmark score in the database, while the Intel Core 7 251E has no benchmark entries. This does not mean the 251E lacks capability, it means the database contains no direct measurements for it, so all head-to-head analysis must rely on the 265K's results and the architectural differences documented between the two parts.

The 265K's Cinebench results establish its multi-threaded performance profile. In Cinebench R15 multicore, it scores 5020 points. In R20 multicore, the score rises to 20918, and in R23 multicore, it reaches 35850. These numbers indicate strong scaling across the 20 threads the processor supports. The single-core results tell a similar story: 708 in R15, 2953 in R20, and 2020 in R23. The R23 single-core score of 2020 is notable because it exceeds 2000 points, a threshold that places the chip among capable single-thread performers in the database's recorded results.

Geekbench results reinforce the picture. The 265K records a multicore score of 23085 and a singlecore score of 2713. These numbers align with the Cinebench data, showing consistent performance across different benchmark suites. The multicore Geekbench score is roughly 8.5 times the singlecore score, which is a plausible ratio for a 20-thread processor with the clock speeds listed in the database.

PassMark results cover more specialized workloads. The 265K scores 665554 in data compression, 48246 in data encryption, and 54333 in extended instructions. In prime number finding, it scores 491. Floating point math reaches 189629, while integer math reaches 143242. The multithread score is 58594, and the physics score is 3731. Random string sorting produces 79752. The single-thread PassMark score is 4928, and a duplicate entry with the same value appears under a slightly different test name, confirming the measurement.

The 265K's aggregate statistics place it in the 94th percentile of all CPUs in the database, with an average benchmark score of 70879. Its nearest rivals in the database are the Intel Xeon 6511P at 71051 (a 0.2 percent lower score), the Intel Xeon Platinum 8270 at 71370 (0.7 percent lower), the Intel Core i7-14700KF at 70163 (1 percent higher), and the AMD Ryzen 7 9700F at 69996 (1.3 percent higher). These deltas are small, meaning the 265K sits in a tight cluster with those four processors. The 265K trails the Xeon parts by margins under one percent, and it leads the Core i7 and Ryzen parts by margins around one percent. This positioning indicates that the 265K's performance is competitive with a range of high-end server and desktop chips, despite differences in their target markets.

Where Each One Wins

The Intel Core Ultra 7 265K wins every benchmark category for which the database has records. This is a straightforward result: it holds scores in Cinebench R15, R20, R23, Geekbench, and nine PassMark subtests. No recorded data exists for the Intel Core 7 251E, so its win count in the head-to-head comparison is zero.

The 265K's strengths are evenly distributed across workload types. In rendering and CPU-constrained tasks, the Cinebench multicore scores show strong parallel scaling. In general-purpose computing, the Geekbench results indicate balanced single and multicore capability. In encryption and compression tasks, the PassMark scores suggest the chip handles data transformation workloads efficiently. The physics score of 3731 and the floating point score of 189629 point to competent number-crunching in scientific and simulation contexts.

The 251E's potential advantages must be inferred from its specification sheet rather than measured results. It has 24 cores and 32 threads, which is 4 more cores and 12 more threads than the 265K. It also has a larger shared L3 cache at 36 MB versus 30 MB. These features could favor heavily threaded workloads that exceed 20 threads, though the database contains no benchmark runs to confirm this. The 251E also supports DDR4 alongside DDR5, which may matter for systems using older memory, but this is a compatibility feature, not a performance one.

The 251E has a lower thermal design power at 65 watts versus 125 watts for the 265K. Lower power draw can translate to reduced cooling requirements and potentially quieter operation in compact systems. The 251E also uses a 10 nm process node from Intel, while the 265K uses a 3 nm node from TSMC, which affects power and density characteristics. These are qualitative differences in the absence of measured efficiency data.

Architecture Differences

The two processors come from different families and are built on different foundations. The Intel Core 7 251E belongs to the Bartlett Lake generation, while the Intel Core Ultra 7 265K belongs to the Arrow Lake generation, specifically the Core Ultra Series 2 with the Arrow Lake-S codename. This generational split accounts for many of their differences.

The process nodes diverge sharply. The 251E is fabricated on a 10 nm node at Intel's foundry. The 265K is fabricated on a 3 nm node at TSMC. The 265K lists a transistor count of 17,800 million and a die size of 243 mm². The 251E lists no transistor count and a die size of 257 mm². The 265K packs far more transistors into a slightly smaller die, which is consistent with the denser 3 nm process.

Core and thread counts differ. The 251E has 24 cores and 32 threads. The 265K has 20 cores and 20 threads. The 251E supports simultaneous multithreading, as evidenced by its thread count exceeding its core count. The 265K does not, since its thread count equals its core count. This is a fundamental architectural choice: the 251E relies on two threads per core for some of its throughput, while the 265K uses more physical cores without SMT.

Cache hierarchies are structured differently. The 251E has 80 KB of L1 per core, 2 MB of L2 per core, and 36 MB of shared L3. The 265K has 192 KB of L1 per core, 3 MB of L2 per core, and 30 MB of shared L3. The 265K's per-core caches are larger, which can benefit single-threaded and low-thread-count workloads. The 251E's larger L3 pool benefits data sharing across many threads.

Clock speeds differ in both directions. The 251E has a base clock of 2.10 GHz and a boost clock of 5.60 GHz. The 265K has a base clock of 3.90 GHz and a boost clock of 5.50 GHz. The 265K's base clock is substantially higher, indicating it sustains higher frequencies under load. The 251E's boost clock is 0.10 GHz higher, a marginal difference that only matters in short single-thread bursts.

Memory support and bandwidth diverge. The 251E supports both DDR4 and DDR5, while the 265K supports only DDR5. Both use dual-channel memory buses. The 251E's memory bandwidth is listed at 89.6 GB/s, while the 265K reaches 102.4 GB/s. The 265K's higher bandwidth aligns with its newer platform and faster memory capabilities. Both processors support ECC memory.

PCIe configurations differ. The 251E provides Gen 5 with 16 lanes from the CPU. The 265K provides Gen 5 with 20 lanes from the CPU. The extra four lanes on the 265K allow for additional high-speed devices. Integrated graphics also differ: the 251E uses UHD Graphics 770, while the 265K uses Arc Xe-LPG Graphics 64EU. The Arc branding indicates a newer graphics architecture.

The sockets are incompatible. The 251E uses Intel Socket 1700, while the 265K uses Intel Socket 1851. These are physically different sockets, meaning the two processors cannot be installed in the same motherboard. The 251E has a locked multiplier, while the 265K has an unlocked multiplier, allowing user-controlled overclocking on the latter.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Core 7 251E has 24 cores and 32 threads. The Intel Core Ultra 7 265K has 20 cores and 20 threads. The 251E has 4 more cores and 12 more threads, and it is the only one of the two that supports simultaneous multithreading.

Q: How do the base and boost clocks compare?

A: The 251E has a base clock of 2.10 GHz and a boost clock of 5.60 GHz. The 265K has a base clock of 3.90 GHz and a boost clock of 5.50 GHz. The 265K has a significantly higher base clock, while the 251E has a slightly higher boost clock by 0.10 GHz.

Q: What memory types does each processor support?

A: The 251E supports both DDR4 and DDR5. The 265K supports only DDR5. Both use dual-channel memory buses. The 251E has a memory bandwidth of 89.6 GB/s, and the 265K has 102.4 GB/s. Both support ECC memory.

Q: Which processor has a higher recorded benchmark score?

A: The 265K has an average benchmark score of 70879 and sits in the 94th percentile of all CPUs in the database. The 251E has no recorded benchmark scores and sits in the 50th percentile by default. Every recorded benchmark in this comparison belongs to the 265K.

Q: Are the two processors compatible with the same motherboard?

A: No. The 251E uses Intel Socket 1700, and the 265K uses Intel Socket 1851. They are physically different sockets and cannot be interchanged on the same motherboard. The 251E also has a locked multiplier, while the 265K has an unlocked multiplier.

Q: What are the process node and foundry differences?

A: The 251E is fabricated on a 10 nm process at Intel. The 265K is fabricated on a 3 nm process at TSMC. The 265K lists 17,800 million transistors on a 243 mm² die, while the 251E lists no transistor count on a 257 mm² die.

Specification Differences

The following fields differ between the two processors according to the database:

• Cores: 24 (251E) versus 20 (265K)
• Threads: 32 (251E) versus 20 (265K)
• Base Clock: 2.10 GHz (251E) versus 3.90 GHz (265K)
• Boost Clock: 5.60 GHz (251E) versus 5.50 GHz (265K)
• TDP: 65 watts (251E) versus 125 watts (265K)
• Socket: Intel Socket 1700 (251E) versus Intel Socket 1851 (265K)
• Architecture: Bartlett Lake (251E) versus Arrow Lake (265K)
• Codename: Bartlett Lake (251E) versus Arrow Lake-S (265K)
• Generation: Core 7 (Bartlett Lake) (251E) versus Ultra 7 (Arrow Lake) (265K)
• Process Node: 10 nm (251E) versus 3 nm (265K)
• Foundry: Intel (251E) versus TSMC (265K)
• Transistors: Not listed (251E) versus 17,800 million (265K)
• Die Size: 257 mm² (251E) versus 243 mm² (265K)
• L1 Cache: 80 KB per core (251E) versus 192 KB per core (265K)
• L2 Cache: 2 MB per core (251E) versus 3 MB per core (265K)
• L3 Cache: 36 MB shared (251E) versus 30 MB shared (265K)
• Memory Support: DDR4, DDR5 (251E) versus DDR5 (265K)
• Memory Bandwidth: 89.6 GB/s (251E) versus 102.4 GB/s (265K)
• PCIe: Gen 5, 16 Lanes (251E) versus Gen 5, 20 Lanes (265K)
• Integrated Graphics: UHD Graphics 770 (251E) versus Arc Xe-LPG Graphics 64EU (265K)
• Launch MSRP: $384 (251E) versus $394 (265K)
• Multiplier Unlocked: False (251E) versus True (265K)
• Part Number: SRQDUQ657 (251E) versus SRQCW (265K)
• Release Date: 2025-01-12 (251E) versus 2024-10-23 (265K)