Intel Core Ultra 7 255HX vs Intel Xeon Gold 6338T Comparison

The Verdict

The Intel Core Ultra 7 255HX and Intel Xeon Gold 6338T serve completely different markets, and the benchmark data makes that split obvious. The Core Ultra 7 255HX wins 11 of the 17 recorded head-to-head tests, while the Xeon Gold 6338T takes 6. If your workload rewards high single-thread speed, encryption throughput, floating-point math, or prime-number finding, the Core Ultra 7 255HX is the clear choice. If you need massive thread counts for integer-heavy server tasks, data compression, or extended instruction workloads, the Xeon Gold 6338T holds its ground.

The Core Ultra 7 255HX posts a 94.3% higher Passmark single-thread score than the Xeon, and it leads by 60.3% in Cinebench R15 multicore. The Xeon counters with a 49.7% win in Cinebench R23 single-core and a 16.5% edge in Passmark integer math. The Xeon also wins in data compression by 7.7%, extended instructions by 4.7%, and random string sorting by 5.9%. The Core Ultra wins the overall average benchmark score, 62,738 to 60,572. Both sit near the top of the database, with the Core Ultra at the 93rd percentile and the Xeon at the 92nd.

For a mobile workstation user, the Core Ultra 7 255HX is the practical pick. For a server administrator running integer-heavy or compression-heavy workloads, the Xeon Gold 6338T remains a valid option. The data does not support choosing the Xeon for single-thread work; it wins only one of the three single-core Cinebench tests, and that win is a narrow one in R15. The Core Ultra wins the other two single-core tests decisively.

Architecture Differences

The two processors come from different Intel design lineages. The Core Ultra 7 255HX uses Arrow Lake, specifically the Arrow Lake-HX variant, built on a TSMC 3 nm process. It packs 20 cores and 20 threads with a 2.40 GHz base clock and a 5.20 GHz boost clock. The Xeon Gold 6338T uses Ice Lake, specifically Ice Lake-SP, on Intel's 10 nm process. It has 24 cores and 48 threads with a 2.10 GHz base clock and a 3.40 GHz boost clock. The Xeon has more cores and more threads, but each of its cores runs at lower clocks.

Cache layouts differ substantially. The Core Ultra 7 255HX provides 192 KB of L1 cache per core, 3 MB of L2 cache per core, and 30 MB of shared L3 cache. The Xeon Gold 6338T provides 64 KB of L1 per core, 1 MB of L2 per core, and 36 MB of shared L3 cache. The Core Ultra has a much larger per-core L1 and L2, while the Xeon has a larger shared L3 pool.

The memory platforms diverge sharply. The Core Ultra 7 255HX supports DDR5 memory over a dual-channel bus with 102.4 GB/s of bandwidth and no ECC support. The Xeon Gold 6338T supports DDR4 memory over an eight-channel bus with 204.8 GB/s of bandwidth and ECC support. That is exactly double the memory bandwidth on the Xeon side, a critical advantage for memory-bound server workloads.

PCIe capabilities also split the two. The Core Ultra 7 255HX offers Gen 5 with 20 lanes from the CPU. The Xeon Gold 6338T offers Gen 4 with 64 lanes from the CPU. The Core Ultra has the newer PCIe standard, while the Xeon has more than three times the lane count.

The Core Ultra 7 255HX includes integrated graphics, specifically Arc Xe-LPG Graphics with 64 execution units. The Xeon Gold 6338T has no integrated graphics. The Core Ultra also has an unlocked multiplier, while the Xeon multiplier is locked. The Xeon is a server/workstation part on Intel Socket 4189, while the Core Ultra is a mobile part on Intel BGA 2114.

Head-to-Head Benchmarks

The Cinebench results tell a mixed story. In Cinebench R15 multicore, the Core Ultra 7 255HX scores 4,916 against the Xeon's 3,067, a 60.3% advantage. In Cinebench R20 multicore, the Core Ultra leads 17,187 to 12,780, a 34.5% edge. In Cinebench R23 multicore, the margin narrows to 7.2%, with the Core Ultra at 32,612 and the Xeon at 30,430. The Xeon's 48 threads close the gap as the test scales, but the Core Ultra still wins.

Single-core Cinebench results are inconsistent. In Cinebench R15 single-core, the Xeon Gold 6338T wins 432 to 327, a 24.3% margin. In Cinebench R20 single-core, the Core Ultra wins 2,426 to 1,804, a 34.5% margin. In Cinebench R23 single-core, the Xeon wins 4,296 to 2,163, a 49.7% margin. That R23 result is the Xeon's largest single-core win, and it is a stark reversal of the R20 result. The recorded data shows no consistent single-core champion between these two.

Passmark results break cleanly by workload type. The Core Ultra 7 255HX dominates in data encryption, scoring 39,499 against 24,677, a 60.1% win. In find prime numbers, the Core Ultra scores 400 against 118, a 239% advantage, the largest single delta in the entire comparison. In floating point math, the Core Ultra leads 160,624 to 90,584, a 77.3% margin. In physics, the Core Ultra scores 2,926 against 1,160, a 152.2% win. In multithread, the Core Ultra leads 48,234 to 35,801, a 34.7% margin. In single-thread tests, the Core Ultra scores 4,562 against 2,348, a 94.3% advantage.

The Xeon Gold 6338T wins the remaining Passmark tests. In data compression, it scores 557,816 against 515,143, a 7.7% margin. In extended instructions, it leads 43,292 to 41,247, a 4.7% edge. In integer math, it wins 152,275 to 127,126, a 16.5% margin. In random string sorting, it leads 66,495 to 62,591, a 5.9% edge.

FAQ

Q: Which processor has better single-thread performance?

A: It depends on the test. The Core Ultra 7 255HX wins Passmark single-thread by 94.3% (4,562 vs 2,348) and Cinebench R20 single-core by 34.5% (2,426 vs 1,804). The Xeon Gold 6338T wins Cinebench R15 single-core by 24.3% (432 vs 327) and Cinebench R23 single-core by 49.7% (4,296 vs 2,163).

Q: How does memory bandwidth compare?

A: The Xeon Gold 6338T provides 204.8 GB/s over an eight-channel DDR4 bus, exactly double the Core Ultra 7 255HX's 102.4 GB/s over a dual-channel DDR5 bus. The Xeon also supports ECC memory, while the Core Ultra does not.

Q: Which processor has more cores and threads?

A: The Xeon Gold 6338T has 24 cores and 48 threads. The Core Ultra 7 255HX has 20 cores and 20 threads. The Xeon has 4 more cores and 28 more threads.

Q: Which processor wins in encryption workloads?

A: The Core Ultra 7 255HX wins decisively. It scores 39,499 in Passmark data encryption against the Xeon's 24,677, a 60.1% advantage.

Q: Does the Xeon Gold 6338T have integrated graphics?

A: No. The Xeon Gold 6338T has no integrated graphics. The Core Ultra 7 255HX includes Arc Xe-LPG Graphics with 64 execution units.

Q: Which processor has better PCIe support?

A: The Xeon Gold 6338T offers 64 PCIe Gen 4 lanes from the CPU. The Core Ultra 7 255HX offers 20 PCIe Gen 5 lanes from the CPU. The Xeon has more lanes, while the Core Ultra uses the newer standard.

Where Each One Wins

The Core Ultra 7 255HX is the choice for workloads that depend on high clock speeds and per-core efficiency. Its 5.20 GHz boost clock drives a 94.3% single-thread Passmark win and a 60.1% encryption win. Floating-point math and physics simulations also fall squarely in its favor, with 77.3% and 152.2% margins respectively. Prime-number finding is not even close: the Core Ultra scores 400 against 118, a 239% advantage. Multithreaded rendering through Cinebench also favors the Core Ultra, particularly in R15 where it leads by 60.3%. The integrated Arc graphics make it a self-contained mobile solution, and the unlocked multiplier allows tuning for users who want it.

The Xeon Gold 6338T wins in server-style integer and data workloads. Integer math shows a 16.5% margin, data compression a 7.7% margin, and random string sorting a 5.9% margin. Extended instructions edge ahead by 4.7%. The 48 threads and 36 MB of shared L3 cache support these throughput-oriented tasks. The eight-channel memory setup with 204.8 GB/s of bandwidth and ECC support makes it suitable for memory-heavy server environments. The 64 PCIe Gen 4 lanes provide extensive I/O expansion, which matters for workstation builds with many storage or accelerator devices. The Xeon's Cinebench R23 single-core win, 4,296 to 2,163, is an anomaly in an otherwise Core Ultra-dominated single-thread picture, but it is the largest single-core margin recorded in this comparison.

Specification Differences

The Core Ultra 7 255HX and Xeon Gold 6338T differ on nearly every major specification. The Core Ultra has 20 cores and 20 threads, while the Xeon has 24 cores and 48 threads. Base clocks are 2.40 GHz for the Core Ultra and 2.10 GHz for the Xeon. Boost clocks are 5.20 GHz and 3.40 GHz respectively. The Core Ultra uses a 3 nm TSMC process; the Xeon uses Intel's 10 nm process. The Core Ultra has 17,800 million transistors on a 243 mm² die; the Xeon's transistor count and die size are not recorded.

Cache configurations differ per core. The Core Ultra has 192 KB of L1 per core and 3 MB of L2 per core. The Xeon has 64 KB of L1 per core and 1 MB of L2 per core. Shared L3 is 30 MB on the Core Ultra and 36 MB on the Xeon. The Core Ultra supports DDR5 memory over dual-channel with 102.4 GB/s bandwidth and no ECC. The Xeon supports DDR4 over eight-channel with 204.8 GB/s bandwidth and ECC. PCIe is Gen 5 with 20 lanes on the Core Ultra versus Gen 4 with 64 lanes on the Xeon. The Core Ultra has integrated Arc Xe-LPG Graphics with 64 execution units; the Xeon has none. The Core Ultra is a mobile part with an unlocked multiplier; the Xeon is a server/workstation part with a locked multiplier. The Core Ultra uses Intel BGA 2114, and the Xeon uses Intel Socket 4189.