AMD EPYC 7642 vs AMD EPYC 8324P Comparison

The AMD EPYC 7642 and the AMD EPYC 8324P represent two distinct approaches to server processing, separated by four years of architectural evolution. The data shows a fascinating split: the older 48-core Rome chip dominates nearly every workload, while the newer 32-core Siena part takes a clear single-thread lead. This comparison reveals that core count and cache size often outweigh generational efficiency gains in heavily threaded enterprise tasks.

Head-to-Head Benchmarks

The benchmark results are decisively lopsided in favor of the EPYC 7642, which wins 15 of the 17 recorded tests. The largest margins appear in specialized compute tasks. In the PassMark find prime numbers test, the EPYC 7642 scores 496 against 347 for the EPYC 8324P, a 42.9% advantage. Data encryption shows a 36.7% lead (86397 vs 63195), and floating point math is 30.8% higher (181887 vs 139022). These are not marginal differences; they indicate substantial capability gaps in mathematical and cryptographic operations.

The Cinebench suite shows a consistent, tighter lead for the older chip. In Cinebench R23 multi-core, the EPYC 7642 scores 49975 versus 48557, which is a 2.9% advantage. The single-core result in the same test is also 2.9% ahead (7055 vs 6855). This pattern repeats across R15 and R20, with the EPYC 7642 maintaining a 2.9% to 3% lead in every Cinebench test. The consistency suggests a fundamental advantage in sustained multi-core throughput, likely from its larger L3 cache and higher core count.

The EPYC 8324P does claim two wins, both in single-threaded PassMark tests. It scores 2367 in PassMark single_thread (and singlethread), while the EPYC 7642 scores 2052. That is a 13.3% advantage for the newer part. This is a notable result, indicating that despite fewer cores, the Zen 4c design is more efficient in single-threaded execution. However, this single point of superiority does not translate into broader success across other workloads.

The data suggests that the EPYC 7642 is the dominant performer for most server tasks, but the EPYC 8324P has a clear edge in lightly threaded applications. The largest deltas are in areas that benefit from raw parallelism, while the smallest deltas (1.1% in random_string_sorting) show that even in memory-heavy tasks, the older chip manages to stay ahead.

Architecture Differences

The two processors are built on fundamentally different designs. The EPYC 7642 uses the Zen 2 architecture, codenamed Rome, fabricated on a 7 nm process by TSMC. The EPYC 8324P uses Zen 4c, codenamed Siena, built on a 5 nm process, also by TSMC. The node shrink is significant, but the two chips are not direct competitors in design philosophy.

The EPYC 7642 packs 48 cores and 96 threads, while the EPYC 8324P has 32 cores and 64 threads. That core count difference is a primary driver of the former’s multi-core wins. Cache allocation also differs. The 7642 has 256 MB of shared L3 cache, while the 8324P has 128 MB. The 7642 has 96 KB of L1 and 512 KB of L2 per core, whereas the 8324P has 64 KB of L1 and 1 MB of L2 per core. The larger per-core L2 on the newer part helps with some single-threaded operations, but the massive L3 on the older part is crucial for shared workloads.

Memory support is another differentiator. The 7642 uses DDR4 with an eight-channel memory bus, delivering 204.8 GB/s of bandwidth. The 8324P moves to DDR5 with a six-channel bus, achieving 230.4 GB/s. The newer chip has higher peak bandwidth despite fewer channels, which explains its competitive performance in some streaming tests. PCIe support also differs: the 7642 offers Gen 4, while the 8324P provides Gen 5 with 96 lanes.

The transistor count is a stark contrast. The 7642 has 3,800 million transistors on a 74 mm² die. The 8324P has 35,500 million transistors across 4x 73 mm² dies. This is a massive increase in transistor density, enabled by the 5 nm process. The power draw is modestly different, with the 7642 rated at 225 W TDP and the 8324P at 180 W, but these numbers do not directly indicate performance efficiency.

FAQ

Q: Which processor has a higher multi-core benchmark score?

A: The AMD EPYC 7642 wins all multi-core Cinebench tests. In Cinebench R23 multi-core, it scores 49975, which is 2.9% higher than the EPYC 8324P’s 48557.

Q: Does the newer EPYC 8324P win any benchmark?

A: Yes, it wins two tests: PassMark single_thread and PassMark single_thread_2, scoring 2367 in both, a 13.3% higher result than the EPYC 7642’s 2052.

Q: How does the memory bandwidth compare between the two?

A: The EPYC 8324P has a higher peak memory bandwidth of 230.4 GB/s with its six-channel DDR5 setup, while the EPYC 7642 has 204.8 GB/s with its eight-channel DDR4 setup.

Q: What is the difference in L3 cache size?

A: The EPYC 7642 has 256 MB of shared L3 cache, while the EPYC 8324P has 128 MB of shared L3 cache.

Q: Are both processors on the same socket?

A: No, they are not. The EPYC 7642 uses AMD Socket SP3, while the EPYC 8324P uses AMD Socket SP6.

Q: Which processor has more transistor count?

A: The EPYC 8324P has 35,500 million transistors, compared to the EPYC 7642’s 3,800 million transistors.

Specification Differences

• Cores: 48 (7642) vs 32 (8324P)
• Threads: 96 (7642) vs 64 (8324P)
• Base Clock: 2.40 GHz (7642) vs 2.65 GHz (8324P)
• Boost Clock: 3.40 GHz (7642) vs 3.00 GHz (8324P)
• TDP: 225 W (7642) vs 180 W (8324P)
• Socket: SP3 (7642) vs SP6 (8324P)
• Architecture: Zen 2 (7642) vs Zen 4c (8324P)
• Process Node: 7 nm (7642) vs 5 nm (8324P)
• Transistors: 3,800 million (7642) vs 35,500 million (8324P)
• Die Size: 74 mm² (7642) vs 4x 73 mm² (8324P)
• L1 Cache: 96 KB per core (7642) vs 64 KB per core (8324P)
• L2 Cache: 512 KB per core (7642) vs 1 MB per core (8324P)
• L3 Cache: 256 MB shared (7642) vs 128 MB shared (8324P)
• Memory Support: DDR4 (7642) vs DDR5 (8324P)
• Memory Bus: Eight-channel (7642) vs Six-channel (8324P)
• Memory Bandwidth: 204.8 GB/s (7642) vs 230.4 GB/s (8324P)
• PCIe: Gen 4 (7642) vs Gen 5, 96 Lanes (8324P)
• Release Date: 2019-08-06 (7642) vs 2023-09-17 (8324P)
• Launch MSRP: none for 7642, $1895 for 8324P

The Verdict

The benchmark data is clear: the AMD EPYC 7642 is the superior processor for most heavy, multi-threaded server workloads. It wins 15 of 17 tests, with notable margins in encryption, prime number calculation, and floating point math. The 48-core design and 256 MB L3 cache provide a decisive advantage in parallel tasks. For applications that scale across cores, such as database compression, rendering, or scientific simulation, the 7642 is the correct choice.

The EPYC 8324P is the better option for single-threaded performance. Its 13.3% lead in PassMark single-thread tests indicates it handles serial tasks more efficiently. This could matter for workloads that are latency-sensitive or poorly parallelized, such as certain database operations or legacy applications. The 8324P also has a lower TDP of 180 W, which can be relevant for power-dense deployments.

The data shows no clear winner for all use cases. The 7642 is a multi-core powerhouse, while the 8324P is a more balanced, modern part with a single-thread edge. The 7642’s older 7 nm process and higher TDP do not prevent it from outperforming in the database’s measurements. For broader server workloads, the 7642 is the default option. For niche, single-thread-critical applications, the 8324P is justifiable.

Where Each One Wins

AMD EPYC 7642 wins in: Cinebench R15, R20, and R23 single and multi-core tests, with margins from 2.9% to 3.0%. PassMark data compression (21.9% ahead), data encryption (36.7% ahead), extended instructions (14.2% ahead), find prime numbers (42.9% ahead), floating point math (30.8% ahead), integer math (22.9% ahead), multithread (2.9% ahead), physics (9.9% ahead), and random string sorting (1.1% ahead). This is a decisive sweep of productivity and computational workloads.

AMD EPYC 8324P wins in PassMark single-thread tests (both variants), scoring 2367 versus 2052, a 13.3% advantage. This is its sole domain, but it is a meaningful one for specific applications that cannot leverage multiple cores effectively. The 8324P also has a higher boost clock? No, the 7642 has a higher boost clock (3.40 vs 3.00 GHz). The single-thread win is likely due to the architectural improvements in Zen 4c and its higher base clock (2.65 GHz vs 2.40 GHz).