AMD EPYC 9684X vs AMD EPYC 9755 Comparison

FAQ

Q: How do the two processors compare in overall average benchmark score?

A: The AMD EPYC 9755 records an average benchmark score of 505,778, while the AMD EPYC 9684X records 266,914. The 9755 sits in the 100th percentile of all CPUs in the database, whereas the 9684X is in the 99th percentile.

Q: Which processor wins in single-threaded performance?

A: The AMD EPYC 9755 leads in all single-thread tests. In Cinebench R23 single-core, it scores 19,959 against 14,591 for the 9684X, a 36.8% advantage. The PassMark single-thread score is 3,503 for the 9755 versus 2,891 for the 9684X, a 21.2% edge.

Q: What is the largest performance gap between the two chips?

A: The biggest delta appears in PassMark floating point math, where the 9755 scores 922,900 versus 472,174 for the 9684X, a 95.5% lead. The smallest gap is in PassMark find prime numbers, with the 9755 ahead by just 1.3% (2,047 vs 2,020).

Q: Do both processors support the same memory and expansion standards?

A: Both use DDR5 memory with a twelve-channel memory bus and PCIe Gen 5 with 128 lanes (CPU only). However, the 9755 delivers 576.0 GB/s of memory bandwidth versus 460.8 GB/s for the 9684X.

Q: What are the core and thread counts for each?

A: The EPYC 9755 has 128 cores and 256 threads. The EPYC 9684X has 96 cores and 192 threads. Both are unlocked-multiplier-free server parts on the AMD Socket SP5 platform.

Q: Which chip has more L3 cache?

A: The EPYC 9684X carries 1152 MB of shared L3 cache, more than double the 512 MB shared L3 on the EPYC 9755. The 9755 has a larger L1 cache per core at 80 KB versus 64 KB, while both share 1 MB of L2 per core.

The Verdict

The data points to a clear split in workload suitability. The AMD EPYC 9755 wins all 17 head-to-head benchmark comparisons recorded in the database. Its average benchmark score of 505,778 is roughly 89.5% higher than the 9684X's 266,914, and it holds the 100th percentile position against the 99th for its rival. For any workload measured here, the 9755 is the faster part, and often by a wide margin.

The EPYC 9684X still has a role. Its 1152 MB of L3 cache is the largest in this comparison, and that capacity can matter for in-memory database or analytics workloads where data locality outweighs raw compute. But the benchmark results do not include a test that favors that cache advantage. In the measured metrics, the 9684X trails in every category, from Cinebench multi-core to PassMark integer math.

Buyers should pick the EPYC 9755 when thread count and throughput dominate: high-density virtualization, large-scale compilation, or heavy floating-point simulation. The 9755 offers 128 cores, a 2.70 GHz base clock, a 4.10 GHz boost clock, and 500 W TDP, with the highest single-thread and multi-thread scores in this pairing.

Choose the EPYC 9684X if the workload is known to scale with L3 capacity and the lower 400 W TDP fits a power envelope. It is not faster in any recorded benchmark, but its 96 cores and 1152 MB cache represent a different balance. The data does not show a scenario where the 9684X outperforms the 9755, so the decision rests on cache sensitivity and thermal budget rather than measured speed.

Head-to-Head Benchmarks

The EPYC 9755 dominates the Cinebench suite with a consistent 36.8% lead across all six tests. In Cinebench R15 multi-core, it scores 14,250 against 10,418; in R20 multi-core, 59,378 versus 43,409; and in R23 multi-core, 141,378 versus 103,355. Single-core results follow the same pattern: R15 at 2,011 versus 1,470, R20 at 8,382 versus 6,128, and R23 at 19,959 versus 14,591. The uniform delta suggests a per-clock and per-core advantage working together, not a single bottleneck.

PassMark multi-thread shows the same 36.8% gap, with the 9755 at 166,328 and the 9684X at 121,595. That alignment with the Cinebench deltas indicates the 9755's core count and clock speed combine into a steady throughput edge. The PassMark physics test is closer, a 12.6% win for the 9755 at 27,806 versus 24,686, which hints that physics simulation does not scale perfectly with the extra 32 cores.

The largest wins come in math-heavy workloads. PassMark floating point math shows a 95.5% lead for the 9755 (922,900 vs 472,174), and integer math follows at 83.6% (1,549,946 vs 844,145). Extended instructions are 70.4% higher (303,321 vs 177,956), and data compression is 67.4% higher (4,517,407 vs 2,698,807). Data encryption is 59.7% ahead (284,927 vs 178,453), and random string sorting is 63.6% ahead (571,185 vs 349,126).

The narrowest margin is PassMark find prime numbers, where the 9755 wins by only 1.3% (2,047 vs 2,020). This test is often memory-latency sensitive, and the 9684X's large L3 cache likely narrows the gap. Still, the 9755 takes the win.

In single-thread PassMark, the 9755 posts 3,503 versus 2,891, a 21.2% lead. The 9755's 4.10 GHz boost clock and Zen 5 architecture explain much of that gap, since the 9684X boosts to only 3.70 GHz with Zen 4 cores.

Specification Differences

The two processors share the same socket, AMD Socket SP5, and both are active server/workstation parts with ECC memory support and no integrated graphics. Both use DDR5 with a twelve-channel memory bus and PCIe Gen 5 with 128 CPU-only lanes. Neither has an unlocked multiplier.

Core and thread counts differ: the 9755 has 128 cores and 256 threads; the 9684X has 96 cores and 192 threads. Clock speeds also differ, with the 9755 at 2.70 GHz base and 4.10 GHz boost, while the 9684X runs at 2.55 GHz base and 3.70 GHz boost. TDP is 500 W for the 9755 and 400 W for the 9684X.

Memory bandwidth is not equal: the 9755 reaches 576.0 GB/s, the 9684X 460.8 GB/s. L1 cache per core is 80 KB on the 9755 and 64 KB on the 9684X; L2 is identical at 1 MB per core. L3 differs sharply, with the 9755 carrying 512 MB shared and the 9684X carrying 1152 MB shared.

The 9755 has a launch MSRP of $12,984. The 9684X has a launch MSRP of $14,756. The 9755 was released on 2024-10-09, while the 9684X launched earlier on 2023-06-12.

Architecture Differences

The EPYC 9755 belongs to the EPYC 9005 series, uses the Zen 5 architecture under the Turin codename, and is built on a 4 nm process at TSMC. The EPYC 9684X belongs to the EPYC 9004 series, uses the Zen 4 architecture under the Genoa-X codename, and is built on a 5 nm process at TSMC.

Transistor counts are close: 133,040 million for the 9755 and 135,240 million for the 9684X. Die sizes differ in arrangement, with the 9755 using 16x 70.6 mm² dies and the 9684X using 12x 72 mm² dies. The 9755's smaller process node and higher transistor density support its larger core count within a similar power class.

The 9684X uses the Genoa-X variant of Zen 4, which is the 3D V-Cache lineage in the EPYC 9004 family. That explains its 1152 MB of shared L3, a capacity aimed at cache-heavy server workloads. The 9755, as a Zen 5 Turin part, trades that massive L3 for more cores and higher clocks. Its 512 MB L3 is still large by general-purpose standards, but the architecture prioritizes core throughput and frequency.

Generation labels in the database show the 9755 as EPYC (Zen 5 (Turin)) and the 9684X as EPYC (Zen 4 (Genoa)). The 9755 is the newer design, released in October 2024, while the 9684X dates to June 2023. Both are produced by TSMC and share the SP5 platform, so system compatibility is identical. The architectural gap, Zen 5 versus Zen 4, plus the process shrink from 5 nm to 4 nm, is what drives the measured performance differences across every benchmark category.