AMD EPYC 7663 vs AMD EPYC 9355P Comparison

The AMD EPYC 7663 and AMD EPYC 9355P are both 99th-percentile server processors, yet they represent opposite ends of a design spectrum within AMD’s EPYC lineup. The 7663 is a 56-core Zen 3 part built for massive parallel throughput, while the 9355P is a 32-core Zen 5 part engineered for raw speed and efficiency per thread. Their average benchmark scores are nearly identical—161,973 for the 7663 versus 160,853 for the 9355P—but the distribution of wins tells a more nuanced story. The 9355P takes 13 of 17 head-to-head benchmarks, while the 7663 counters with 4 wins, mostly in encryption and integer-heavy workloads. Below, the data is broken down across architecture, workload suitability, and specific benchmark deltas.

FAQ

Q: Which processor has the higher average benchmark score?

A: The AMD EPYC 7663 scores 161,973 on average, which is 0.7% higher than the 9355P’s 160,853. The 7663 also holds a 0.7% lead over the 9355P in the nearestRivals deltaPct comparison, while the 9355P trails the 7663 by -0.7% from its perspective.

Q: How do they compare in single-threaded performance?

A: The EPYC 9355P dominates single-thread workloads. In Cinebench R23 single-core, it scores 11,670 versus the 7663’s 9,850, a 15.6% advantage. PassMark single-thread results show a larger gap: 3,741 for the 9355P versus 2,606 for the 7663, a 30.3% delta.

Q: Which processor wins in multi-threaded Cinebench tests?

A: The EPYC 9355P wins all Cinebench multi-core tests despite having fewer cores (32 vs. 56). In Cinebench R23 multi-core, it scores 82,666 against the 7663’s 69,773, a 15.6% lead. The same 15.6% delta appears in R15 and R20 multi-core results.

Q: Are there workloads where the EPYC 7663 is clearly better?

A: Yes, particularly in data encryption and integer math. The 7663 scores 111,725 in PassMark data encryption, which is 36.3% higher than the 9355P’s 81,945. In integer math, the 7663 posts 468,096 versus 414,347, a 13% advantage.

Q: What is the core and thread count difference?

A: The EPYC 7663 has 56 cores and 112 threads, while the EPYC 9355P has 32 cores and 64 threads. The 7663 offers 24 more cores and 48 more threads, yet the 9355P still outperforms it in most benchmarks.

Q: Which processor has higher clock speeds?

A: The EPYC 9355P has a base clock of 3.55 GHz and a boost clock of 4.40 GHz. The EPYC 7663 has a base clock of 2.00 GHz and a boost clock of 3.50 GHz. The 9355P’s boost clock is 0.90 GHz higher.

Architecture Differences

The two processors are separated by two full generations of AMD’s server architecture. The EPYC 7663 uses Zen 3, codenamed Milan, built on TSMC’s 7 nm process with 33,200 million transistors across 8 dies of 81 mm² each. The EPYC 9355P uses Zen 5, codenamed Turin, on TSMC’s 4 nm process, packing 66,520 million transistors into 8 dies of 70.6 mm² each. The transistor count nearly doubles for the newer part, while the die size shrinks, indicating a denser and more power-efficient design.

Cache hierarchy differs in per-core allocations. The 7663 has 64 KB of L1 and 512 KB of L2 per core, while the 9355P has 80 KB of L1 and 1 MB of L2 per core. Both share 256 MB of L3, but the newer part’s larger per-core caches suggest better data locality for single-threaded tasks. Memory support also diverges: the 7663 uses DDR4 with an eight-channel bus and 204.8 GB/s bandwidth, whereas the 9355P uses DDR5 with a twelve-channel bus and 576.0 GB/s bandwidth. The 9355P’s memory bandwidth is nearly triple that of the 7663, which is critical for memory-bound server workloads.

Socket compatibility is a major generational break. The 7663 fits AMD Socket SP3, while the 9355P requires AMD Socket SP5. PCIe capabilities also advance: the 7663 offers Gen 4 with 128 lanes (CPU only), while the 9355P provides Gen 5 with the same 128 lanes. Both support ECC memory and lack integrated graphics, but the 9355P’s newer platform brings faster I/O and memory standards. The TDP difference is modest—240 W for the 7663 versus 280 W for the 9355P—but the 9355P delivers significantly more performance per watt given its benchmark results.

Where Each One Wins

The EPYC 9355P is the clear winner in single-threaded and lightly threaded scenarios. Its PassMark single-thread score of 3,741 is 30.3% higher than the 7663’s 2,606, and its Cinebench R23 single-core score of 11,670 beats the 7663’s 9,850 by 15.6%. This makes it the better choice for database queries, web serving, and any workload where latency per request matters more than raw core count. The 9355P also excels in physics simulations, scoring 14,521 in PassMark physics versus 8,020 for the 7663, a 44.8% advantage. Extended instruction workloads favor the 9355P as well, with a 31% lead in PassMark extended instructions (106,821 vs. 73,719).

The EPYC 7663, despite losing most benchmarks, has specific niches where its higher core count shines. PassMark data encryption is its strongest win: 111,725 versus 81,945, a 36.3% margin. This suggests the 7663’s larger thread pool accelerates cryptographic operations more effectively than the 9355P’s faster cores. Integer math also favors the 7663, with 468,096 against 414,347 (13% higher), which can benefit workloads like financial modeling or integer-heavy analytics. Data compression and random string sorting are narrow wins for the 7663, with 1.1% and 2.2% margins respectively, indicating that its extra cores provide a slight edge in these parallel data-processing tasks.

For multi-threaded rendering and general compute, the 9355P is surprisingly dominant. It wins every Cinebench multi-core test by 15.6%, despite having 24 fewer cores. PassMark multithread also goes to the 9355P with 97,255 versus 82,087, a 15.6% margin. This means the 9355P’s architectural efficiency—higher clocks, larger caches, and faster memory—overcomes the 7663’s core-count advantage in most parallel workloads.

Specification Differences

The core and thread counts are the most obvious difference: the 7663 has 56 cores and 112 threads, while the 9355P has 32 cores and 64 threads. Clock speeds favor the 9355P, with a base of 3.55 GHz and boost of 4.40 GHz, versus the 7663’s 2.00 GHz base and 3.50 GHz boost. TDP is higher for the 9355P at 280 W, compared to 240 W for the 7663.

Process node and transistor count differ dramatically. The 7663 is on 7 nm with 33,200 million transistors, while the 9355P is on 4 nm with 66,520 million transistors. Die size per chiplet is smaller for the 9355P at 70.6 mm² versus 81 mm², but the newer process allows for more transistors in less space. Cache per core increases from 64 KB L1 and 512 KB L2 on the 7663 to 80 KB L1 and 1 MB L2 on the 9355P; both share 256 MB L3.

Memory support is a generational leap. The 7663 uses DDR4 with an eight-channel bus and 204.8 GB/s bandwidth, while the 9355P uses DDR5 with a twelve-channel bus and 576.0 GB/s bandwidth. Sockets differ (SP3 vs. SP5), as do PCIe generations (Gen 4 vs. Gen 5), though both provide 128 CPU-only lanes. The release dates are separated by several years, with the 7663 launching earlier and the 9355P arriving later. Launch MSRP for the 7663 is $6366, while the 9355P has a launch MSRP of $2998.

Head-to-Head Benchmarks

The largest single-benchmark win for the 9355P is in PassMark physics, where it scores 14,521 against the 7663’s 8,020—a 44.8% delta. This is a massive gap, indicating that the 9355P’s faster cores and newer architecture handle physics calculations far more efficiently. The next biggest win is in PassMark find prime numbers, with the 9355P scoring 1,041 versus 676, a 35.1% lead. Single-thread performance also shows a 30.3% gap in PassMark single-thread (3,741 vs. 2,606), and extended instructions show a 31% delta (106,821 vs. 73,719).

The 9355P’s Cinebench wins are consistent at exactly 15.6% across R15, R20, and R23, for both single-core and multi-core tests. For example, R23 multi-core shows 82,666 for the 9355P versus 69,773 for the 7663. The same 15.6% delta appears in PassMark multithread, where the 9355P scores 97,255 against 82,087. This uniformity suggests a clock-for-clock architectural advantage rather than workload-specific tuning.

The 7663’s biggest win is in PassMark data encryption, where it scores 111,725 versus 81,945, a 36.3% margin. This is the only benchmark where the 7663 wins by more than 13%. Integer math is its second-largest win, with 468,096 versus 414,347, a 13% delta. Data compression and random string sorting are narrow victories: 1,447,020 versus 1,431,968 (1.1%) and 184,367 versus 180,482 (2.2%), respectively. The 7663 also wins in floating-point math by a slim margin? No—the data shows the 9355P wins floating-point math with 255,177 versus 251,535, a 1.4% delta.

Overall, the 9355P wins 13 benchmarks to the 7663’s 4. The average scores are nearly tied, but the 9355P’s wins are often by double-digit margins, while the 7663’s wins are mostly single-digit except for encryption. This indicates that for most workloads, the 9355P is the superior processor, but the 7663 retains a distinct advantage in security and integer-heavy applications.