Intel Core Ultra 7 270K Plus vs Intel Xeon 6521P Comparison

The Intel Xeon 6521P and Intel Core Ultra 7 270K Plus sit at opposite ends of Intel's product stack: the Xeon is a 24-core, 48-thread server/workstation processor on Granite Rapids, while the Ultra 7 is a 24-core, 24-thread desktop chip on Arrow Lake Refresh. The database records 17 head-to-head benchmark comparisons between them, with the Xeon taking 8 wins and the Ultra 7 taking 9, yet the Xeon holds the higher average benchmark score (105845 versus 93785) and the higher percentile ranking (97 versus 96). The results are not a simple core-count story: the Xeon dominates single-core Cinebench and integer-heavy Passmark tests, while the Ultra 7 counters with floating-point math, encryption, and Passmark's single-thread test.

Head-to-Head Benchmarks

The largest margin in the entire comparison belongs to the Xeon in Cinebench R23 single-core: 7998 versus 2439, a 227.9% advantage. The same pattern appears in Cinebench R15 single-core, where the Xeon scores 806 against 354, a 127.7% lead. These are not marginal gaps; they show a fundamental difference in lightly threaded Cinebench execution.

The Xeon also wins the Cinebench R23 multi-core test, 56658 to 44253, a 28% margin. That is the largest multi-core win in the comparison. The Ultra 7, however, takes Cinebench R15 multi-core by 6656 to 5711 (a 14.2% deficit for the Xeon) and Cinebench R20 multi-core by 24461 to 23796 (a 2.7% deficit). The two chips trade Cinebench generations: the Xeon wins the newest R23 multi-core, the Ultra 7 wins the older R15 and R20 multi-core tests.

In Passmark, the Xeon's wins are concentrated in integer and compression workloads. Integer math goes 246263 to 175986, a 39.9% lead. Physics goes 5972 to 4064, a 46.9% lead. Data compression goes 967721 to 804322, a 20.3% lead. Extended instructions go 72820 to 63506, a 14.7% lead. Random string sorting goes 104517 to 96945, a 7.8% lead.

The Ultra 7 answers in floating-point math: 229491 to 178828, a 22.1% lead. Data encryption goes 59097 to 51221, a 13.3% lead. Find prime numbers goes 615 to 560, an 8.9% lead. Passmark multithread goes 68574 to 66657, a 2.8% lead. And the Passmark single-thread test goes 5068 to 3238, a 36.1% lead for the Ultra 7. The database lists the single-thread score twice (5068 in both "single_thread" and "singlethread") with identical deltas, which reinforces the result.

A notable pattern emerges in the size of the wins. The Xeon's victories are often decisive: 227.9%, 127.7%, 46.9%, 39.9%, and 28% are all large margins. The Ultra 7's biggest wins are 36.1% (single-thread Passmark), 22.1% (floating-point math), and 14.2% (R15 multi-core), with the rest under 14%. So while the Ultra 7 wins more individual tests, the Xeon tends to win by wider margins.

Where Each One Wins

The Xeon 6521P is the clear winner for integer math, physics simulation, data compression, extended instruction workloads, and random string sorting. Its Cinebench R23 single-core and multi-core wins also point to strong performance in the newest renderer. The Xeon's 48 threads double the Ultra 7's 24 threads, and its 144 MB shared L3 cache dwarfs the Ultra 7's 36 MB. The eight-channel memory bus (409.6 GB/s) and 136 PCIe Gen 5 lanes give it a data movement advantage that the desktop chip cannot match.

The Ultra 7 270K Plus wins floating-point math, data encryption, prime number finding, and the Passmark multithread and single-thread tests. Its Cinebench R15 and R20 multi-core wins, though by smaller margins, suggest that in older Cinebench versions it is the faster chip. The Ultra 7 also has a much higher boost clock (5.50 GHz versus 4.10 GHz) and a higher base clock (3.70 GHz versus 2.60 GHz), which helps in clock-sensitive tasks.

The average benchmark score tells a similar story: the Xeon averages 105845, the Ultra 7 averages 93785. The Xeon sits in the 97th percentile of all CPUs, the Ultra 7 in the 96th. The Xeon's nearest rival is the Intel Xeon w7-3555, which averages 106192, 0.3% higher than the 6521P's 105845. The Ultra 7's nearest rival is the Intel Xeon 6520P, which averages 93786, essentially identical to the Ultra 7's 93785. Both chips are surrounded by server and workstation parts in the database, which underscores their positioning.

The Verdict

For server and workstation workloads, the Xeon 6521P is the stronger part. It leads in integer math, physics, data compression, extended instructions, random string sorting, and Cinebench R23 multi-core. Its eight-channel memory bus, 136 PCIe Gen 5 lanes, 144 MB L3 cache, and 48 threads are built for heavy parallel server tasks. The launch MSRP is $1250.

For desktop use, the Ultra 7 270K Plus is the better fit. It wins floating-point math, data encryption, prime number finding, Passmark multithread, and Passmark single-thread. It has integrated graphics (Arc Xe-LPG Graphics 64EU), a 125 W TDP versus 225 W, and an unlocked multiplier. The launch MSRP is $299.

The data does not crown a single winner. The Xeon has the higher average score and the higher percentile, but the Ultra 7 wins more individual tests (9 versus 8). The choice depends on whether the workload is integer-heavy server work (Xeon) or clock-sensitive desktop work (Ultra 7). For a buyer who needs maximum throughput in physics, compression, and integer math, the Xeon's decisive margins justify its position. For a desktop user who values floating-point performance, encryption, and single-thread Passmark results, the Ultra 7 is the data-backed pick.

FAQ

Q: Which processor has more threads?

A: The Intel Xeon 6521P has 48 threads across 24 cores, while the Intel Core Ultra 7 270K Plus has 24 threads across 24 cores.

Q: How much L3 cache does each chip have?

A: The Xeon 6521P has 144 MB of shared L3 cache. The Core Ultra 7 270K Plus has 36 MB of shared L3 cache.

Q: What memory bandwidth do the two support?

A: The Xeon 6521P supports eight-channel DDR5 with 409.6 GB/s bandwidth. The Core Ultra 7 270K Plus supports dual-channel DDR5 with 115.2 GB/s.

Q: Which chip has integrated graphics?

A: The Core Ultra 7 270K Plus includes Arc Xe-LPG Graphics 64EU. The Xeon 6521P has no integrated graphics (N/A).

Q: Which chip is multiplier unlocked?

A: The Core Ultra 7 270K Plus is multiplier unlocked. The Xeon 6521P is not.

Q: What are the release dates?

A: The Xeon 6521P was released on 2025-02-23. The Core Ultra 7 270K Plus was released on 2026-03-10.

Architecture Differences

The two processors come from different foundries and nodes. The Xeon 6521P is built on Intel's 5 nm process with a die size of 598 mm². The Core Ultra 7 270K Plus is built on TSMC's 3 nm process with a die size of 243 mm² and 17,800 million transistors.

Cache layouts differ substantially. The Xeon has 112 KB of L1 per core, 2 MB of L2 per core, and 144 MB of shared L3. The Ultra 7 has 192 KB of L1 per core, 3 MB of L2 per core, and 36 MB of shared L3.

Memory support: both use DDR5, but the Xeon uses an eight-channel bus with 409.6 GB/s bandwidth, while the Ultra 7 uses a dual-channel bus with 115.2 GB/s. Both support ECC memory.

PCIe: the Xeon provides Gen 5 with 136 lanes (CPU only), the Ultra 7 provides Gen 5 with 20 lanes (CPU only).

Sockets: the Xeon uses Intel Socket 4710, the Ultra 7 uses Intel Socket 1851.

The Xeon is a Server/Workstation part; the Ultra 7 is a Desktop part. The Xeon has no integrated graphics; the Ultra 7 has Arc Xe-LPG Graphics 64EU. The Xeon's TDP is 225 W, the Ultra 7's is 125 W. The Xeon is not multiplier unlocked; the Ultra 7 is.