AMD EPYC 9745 vs AMD EPYC 9845 Comparison

The AMD EPYC 9845 and AMD EPYC 9745 are both flagship-class server processors built on the same Zen 5c architecture, but they occupy different rungs on the performance ladder. The data shows a consistent and substantial advantage for the 9845 across every benchmark recorded, with the 9845 winning all 17 head-to-head comparisons. The 9745 is no slouch, but the 9845’s higher core count and larger cache translate into a decisive performance gap that scales from single-threaded tasks to heavily parallel workloads.

Head-to-Head Benchmarks

The most striking pattern in the benchmark data is the uniformity of the 9845’s victory. In Cinebench tests, the 9845 leads by 17% in both R15 and R20 multicore, scoring 13107 versus 11198 and 54615 versus 46659 respectively. The R23 multicore test shows the same 17.1% delta, with the 9845 scoring 130037 against the 9745’s 111093. This consistency suggests the advantage is structural rather than workload-specific—the 9845 simply has more compute resources to bring to bear.

Single-core performance tells a similar story, but with a slightly different nuance. The 9845 wins Cinebench R15 single-core by 17.1% (1850 versus 1580), and the R20 and R23 single-core tests show identical 17.1% deltas (7710 versus 6586, and 18358 versus 15683). The PassMark single-thread test narrows the gap to 12%, with scores of 3144 versus 2806. This indicates that while the 9845 has better per-thread performance, the delta is smaller than in multicore, pointing to the core count as the primary differentiator.

The PassMark suite reveals where the 9845’s advantage becomes more pronounced. Integer math shows the largest gap at 37.8%, with the 9845 scoring 1687531 against the 9745’s 1224315. Floating-point math follows closely at 28.5% (978377 versus 761219), and data encryption shows a 29.4% delta (296808 versus 229447). Prime number finding also favors the 9845 by 28.2% (1255 versus 979). These results indicate that the 9845 excels in compute-heavy, parallelizable workloads where additional cores translate directly into higher throughput.

Data compression and extended instructions show more moderate gains. The 9845 leads data compression by 19.1% (4680013 versus 3929890) and extended instructions by 12.2% (314798 versus 280477). The PassMark multithread test shows a 17.1% advantage (152985 versus 130698), while physics and random string sorting both come in at 14.7% (19631 versus 17122, and 538060 versus 468975). These figures reinforce the overall trend: the 9845 is faster everywhere, but the margin varies from 12% to nearly 38% depending on the workload.

In the broader context of the nearest rivals, the 9845’s average benchmark score of 523613 places it 22.9% ahead of the 9745’s 425973. The 9845 also leads the AMD EPYC 9755 by 3.5% and trails the AMD EPYC 9965 by 12%. The 9745, meanwhile, sits 4.8% ahead of the AMD Ryzen Threadripper PRO 9995WX and 7.4% ahead of the AMD EPYC 9655P. Both processors rank in the 100th percentile versus all CPUs, meaning they represent the top tier of available hardware.

Architecture Differences

Both processors share the same fundamental architecture: Zen 5, codenamed Turin, built on a 3 nm process at TSMC. They use the same AMD Socket SP5 and support DDR5 memory across a twelve-channel bus with 576.0 GB/s of bandwidth. Both also feature PCIe Gen 5 with 128 lanes from the CPU, and both support ECC memory. The core design is identical in per-core cache allocation: 80 KB of L1 per core and 1 MB of L2 per core.

The critical architectural divergence lies in core count and L3 cache. The 9845 packs 160 cores and 320 threads, while the 9745 has 128 cores and 256 threads—a 32-core difference that directly explains much of the performance gap. The L3 cache scales accordingly: the 9845 offers 320 MB shared, while the 9745 provides 256 MB shared. This 64 MB difference in shared L3 cache benefits workloads that rely on large working sets, though the benchmark data suggests the core count is the more significant factor.

Clock speeds present a more nuanced picture. The 9845 has a base clock of 2.10 GHz, while the 9745 starts higher at 2.40 GHz. Both processors boost to 3.70 GHz. The 9745’s higher base clock gives it a theoretical advantage in lightly threaded scenarios, but the benchmark results show the 9845 winning all single-core tests—likely because the 9845’s larger cache and architectural optimizations offset the clock deficit. The 9745 has a higher TDP of 400 watts versus the 9845’s 390 watts, suggesting the 9745 uses more power to drive its higher base frequency.

Neither processor features integrated graphics, and both are locked (multiplier unlocked is false). They share the same production status (Active), release date, and market segment (Server/Workstation). The part numbers differ (100-000001458 for the 9845, 100-000001460 for the 9745), but the underlying architecture is otherwise identical.

The Verdict

The data is unambiguous: the AMD EPYC 9845 is the faster processor in every measured category. Its 22.9% average benchmark advantage over the 9745, combined with wins in all 17 head-to-head tests, makes it the clear choice for workloads that demand maximum compute throughput. The 9845’s 160 cores and 320 threads provide a 25% core-count advantage over the 9745’s 128 cores and 256 threads, and this translates into consistent wins across Cinebench and PassMark suites.

The 9745 is not without merit. Its higher base clock of 2.40 GHz versus the 9845’s 2.10 GHz suggests it may be better suited for power-constrained environments where sustained all-core operation at lower frequencies is preferable. The 9745 also holds a 4.8% advantage over the AMD Ryzen Threadripper PRO 9995WX and a 7.4% edge over the AMD EPYC 9655P, positioning it as a strong performer in its own right. For users who need 128 cores rather than 160, the 9745 delivers most of the architectural benefits at a lower core count.

The choice ultimately comes down to core count and cache requirements. Workloads that scale linearly with cores—such as rendering, scientific computing, and large-scale data processing—will see a meaningful benefit from the 9845’s additional 32 cores and 64 MB of L3 cache. Workloads that are more latency-sensitive or that cannot utilize more than 128 cores may find the 9745’s higher base clock advantageous, though the benchmark data shows the 9845 still wins single-threaded tests. For pure performance, the 9845 is the superior part; for a slightly lower core count with the same architecture, the 9745 remains a capable option.

Specification Differences

The two processors differ in several key specifications. Core count is the most obvious: the 9845 has 160 cores and 320 threads, while the 9745 has 128 cores and 256 threads. The L3 cache differs as well, with the 9845 offering 320 MB shared versus the 9745’s 256 MB shared. Base clock speeds diverge, with the 9845 at 2.10 GHz and the 9745 at 2.40 GHz, though both boost to 3.70 GHz. The TDP also differs: the 9845 is rated at 390 watts, while the 9745 is rated at 400 watts.

The launch MSRP for the 9845 is $13564, and for the 9745 it is $12141. Both processors share the same L1 and L2 cache per core (80 KB and 1 MB respectively), the same memory support (DDR5, twelve-channel, 576.0 GB/s), the same PCIe configuration (Gen 5, 128 lanes), and the same socket (AMD Socket SP5). They are built on the same 3 nm process at TSMC, use the Zen 5 architecture with the Turin codename, and belong to the same generation. The part numbers differ, but the production status, release date, and market segment are identical.

FAQ

Q: Which processor has more cores?

A: The AMD EPYC 9845 has 160 cores and 320 threads, while the AMD EPYC 9745 has 128 cores and 256 threads.

Q: How much faster is the 9845 in multi-core performance?

A: In Cinebench R23 multicore, the 9845 scores 130037 versus the 9745’s 111093, a 17.1% advantage. The average benchmark score shows a 22.9% delta in favor of the 9845.

Q: Does the 9745 have a higher clock speed?

A: Yes, the 9745 has a base clock of 2.40 GHz compared to the 9845’s 2.10 GHz. Both processors boost to 3.70 GHz.

Q: What is the difference in L3 cache?

A: The 9845 has 320 MB of shared L3 cache, while the 9745 has 256 MB of shared L3 cache—a 64 MB difference.

Q: Which processor has a higher TDP?

A: The 9745 has a TDP of 400 watts, which is 10 watts higher than the 9845’s 390 watt TDP.

Q: Are there any benchmarks where the 9745 wins?

A: No. The 9845 wins all 17 head-to-head benchmark comparisons, with deltas ranging from 12% in PassMark single-thread tests to 37.8% in PassMark integer math.