AMD EPYC 4345P vs AMD Ryzen 9 7845HX Comparison

FAQ

Q: Which processor has the higher single-thread performance?

A: The AMD EPYC 4345P is clearly ahead. In Cinebench R23 single-core, it scores 4520 against 1852 for the Ryzen 9 7845HX, a 144.1% advantage. The PassMark single-thread test also favors the EPYC, 4408 versus 3935, a 12% lead.

Q: Which processor is better for heavily threaded workloads like rendering?

A: The results are mixed. The Ryzen 9 7845HX wins Cinebench R15 multi-core with 4320 versus 3227 (25.3% ahead), but the EPYC 4345P wins Cinebench R23 multi-core with 32020 versus 26876 (19.1% ahead). The Ryzen wins PassMark multithread with 45010 versus 36123 (19.7% ahead).

Q: How do their average benchmark scores compare?

A: The EPYC 4345P has an average benchmark score of 48470, placing it in the 90th percentile of all CPUs. The Ryzen 9 7845HX has an average score of 46654, in the 89th percentile. The EPYC is slightly ahead overall.

Q: Which CPU supports ECC memory?

A: Both support ECC memory. The EPYC 4345P is a server/workstation part with DDR5 support and ECC enabled, while the Ryzen 9 7845HX, despite being a mobile processor, also lists ECC memory support.

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

A: The EPYC 4345P has 8 cores and 16 threads. The Ryzen 9 7845HX has 12 cores and 24 threads, giving it a 50% advantage in core count.

Q: Which processor has the higher boost clock?

A: The EPYC 4345P boosts to 5.50 GHz, while the Ryzen 9 7845HX boosts to 5.20 GHz. The EPYC also has a higher base clock at 3.80 GHz versus 3.00 GHz.

Architecture Differences

The two processors come from different AMD generations and target entirely different segments. The EPYC 4345P is built on Zen 5 architecture, codenamed Grado, and belongs to the EPYC 4005 series. It is fabricated on a 4 nm process at TSMC. The Ryzen 9 7845HX uses the older Zen 4 architecture, codenamed Dragon Range, from the Ryzen 7000 series, and is built on a 5 nm process, also at TSMC. The process node difference is not the only architectural gap: the EPYC packs 8,315 million transistors on a 70.6 mm² die, while the Ryzen 9 uses 13,140 million transistors across a dual-die design with 2x 71 mm².

Cache layouts also differ substantially. The EPYC 4345P has 80 KB of L1 cache per core, 1 MB of L2 per core, and 32 MB of shared L3 cache. The Ryzen 9 7845HX has 64 KB of L1 per core, 1 MB of L2 per core, and a larger 64 MB of shared L3 cache. The Ryzen's larger L3 pool reflects its dual-die design and helps in cache-sensitive workloads.

Memory bandwidth is close but not identical. The EPYC supports dual-channel DDR5 with 89.6 GB/s of bandwidth, while the Ryzen 9 supports dual-channel DDR5 with 83.2 GB/s. Both support ECC memory, which is notable for a mobile chip. PCIe connectivity also differs: the EPYC provides Gen 5 with 24 lanes (CPU only), while the Ryzen 9 provides Gen 5 with 28 lanes (CPU only).

The integrated graphics differ as well. The EPYC 4345P includes Radeon Graphics, while the Ryzen 9 7845HX uses a Radeon 610M. The EPYC is an unlocked part? No, it is multiplier locked. The Ryzen 9 7845HX has an unlocked multiplier. The EPYC is a server/workstation part on AMD Socket AM5, while the Ryzen 9 is a mobile part on AMD Socket FL1. Release dates are far apart: the EPYC launched on 2025-05-12, while the Ryzen 9 launched on 2023-01-03.

Head-to-Head Benchmarks

The head-to-head results show a clear split between single-thread and multi-thread strengths. The EPYC 4345P dominates single-core workloads. In Cinebench R23 single-core, it scores 4520 versus 1852 for the Ryzen 9, a massive 144.1% win. The Cinebench R15 single-core result is similarly lopsided: 455 versus 295, a 54.2% advantage. PassMark single-thread also goes to the EPYC: 4408 versus 3935, a 12% lead. Even in PassMark physics, the EPYC wins with 2583 against 2346, a 10.1% margin.

The Ryzen 9 7845HX takes most of the multi-thread and throughput tests. In Cinebench R15 multi-core, it scores 4320 against 3227, a 25.3% win. PassMark multithread goes to the Ryzen with 45010 versus 36123, a 19.7% margin. The Ryzen also wins PassMark integer math (155118 versus 123774, 20.2% ahead), floating point math (94287 versus 74255, 21.2% ahead), data compression (543539 versus 421490, 22.5% ahead), data encryption (32789 versus 23313, 28.9% ahead), extended instructions (41020 versus 31663, 22.8% ahead), random string sorting (63223 versus 46238, 26.9% ahead), and find prime numbers (329 versus 167, 49.2% ahead).

The exception is Cinebench R23 multi-core, where the EPYC wins with 32020 versus 26876, a 19.1% advantage. This is surprising given the Ryzen's 12 cores versus 8, but the Zen 5 architecture and higher clocks appear to compensate in this particular workload. The overall win count is 6 for the EPYC and 9 for the Ryzen 9, but the margin of victory in the EPYC's single-thread wins is often much larger than the Ryzen's multi-thread wins.

The Verdict

The data paints a clear picture: the EPYC 4345P is the stronger single-thread performer, while the Ryzen 9 7845HX is the stronger multi-thread throughput chip in most tests. The EPYC's Cinebench R23 single-core score is 144.1% higher, which is an enormous gap and indicates a generational leap in per-core efficiency. Its PassMark single-thread lead of 12% is more modest but still consistent. The Ryzen 9 wins 9 of 15 head-to-head benchmarks, but many by margins of 20% to 49%, particularly in encryption, prime number finding, and string sorting.

The EPYC also has a higher average benchmark score overall (48470 in the 90th percentile versus 46654 in the 89th percentile for the Ryzen). Its nearest rivals include the Intel Core i5-14600K at 48618 (0.3% ahead of the EPYC), the Intel Core Ultra 5 245HX at 48287 (0.4% behind the EPYC? No, the EPYC is 0.4% ahead of the Ultra 5, and 0.5% ahead of the Xeon Gold 5318H at 48698), and the Intel Core Ultra 5 235A at 48201 (0.4% behind the EPYC? The EPYC is 0.4% ahead of the Ultra 5, 0.5% ahead of the Xeon Gold? The Xeon is 0.5% ahead of the EPYC? The Xeon Gold 5318H is 0.5% ahead of the EPYC, the Ultra 5 235A is 0.6% ahead of the EPYC, the i5-14600K is 0.3% ahead of the EPYC, the Ultra 5 245HX is 0.4% ahead of the EPYC. All within 0.6%.)

The Ryzen 9's nearest rivals include the Intel Xeon w3-2535 at 46653 (0% delta), the AMD Ryzen 9 3900X at 46487 (0.4% behind the Ryzen), the Intel Core i7-13700K at 46881 (0.5% ahead of the Ryzen), and the AMD Ryzen 9 5900 at 46971 (0.7% ahead of the Ryzen).

For a builder choosing between these, the decision comes down to workload. The EPYC is the obvious choice for single-thread-sensitive tasks, and its server pedigree with ECC and AM5 socket makes it a workstation-oriented part. The Ryzen 9 is better for parallel throughput, and its unlocked multiplier and mobile Socket FL1 indicate a different use case.

Specification Differences

The two CPUs differ in nearly every specification category. The EPYC 4345P has 8 cores and 16 threads, while the Ryzen 9 7845HX has 12 cores and 24 threads. Base clocks are 3.80 GHz for the EPYC versus 3.00 GHz for the Ryzen. Boost clocks are 5.50 GHz versus 5.20 GHz. The EPYC has a TDP of 65 watts, while the Ryzen 9 has a TDP of 55 watts.

Socket types are completely different: the EPYC uses AMD Socket AM5, the Ryzen 9 uses AMD Socket FL1. The EPYC is Zen 5 on a 4 nm process; the Ryzen 9 is Zen 4 on a 5 nm process. Transistor counts are 8,315 million versus 13,140 million. Die size is 70.6 mm² for the EPYC versus 2x 71 mm² for the Ryzen.

Cache differs: the EPYC has 80 KB L1 per core, the Ryzen has 64 KB L1 per core. Both have 1 MB L2 per core. L3 is 32 MB shared for the EPYC versus 64 MB shared for the Ryzen. Memory bandwidth is 89.6 GB/s versus 83.2 GB/s, both dual-channel DDR5. PCIe lanes are 24 for the EPYC versus 28 for the Ryzen, both Gen 5 CPU-only.

Integrated graphics are Radeon Graphics for the EPYC versus Radeon 610M for the Ryzen. The EPYC is multiplier locked; the Ryzen is multiplier unlocked. Market segments are Server/Workstation versus Mobile. Release dates are 2025-05-12 versus 2023-01-03. The EPYC has a launch MSRP of $329; the Ryzen has no listed launch MSRP.

Where Each One Wins

The EPYC 4345P wins in single-thread performance, which is its defining strength. Cinebench R23 single-core is 144.1% higher, R15 single-core is 54.2% higher, and PassMark single-thread is 12% higher. It also wins Cinebench R23 multi-core by 19.1%, which is unusual for a CPU with fewer cores, and PassMark physics by 10.1%. This makes it the pick for workloads that depend on per-core speed: database queries, lightly threaded server tasks, and any application where clock speed and IPC matter more than core count. Its 65-watt TDP, AM5 socket, and ECC support reinforce its server/workstation positioning.

The Ryzen 9 7845HX wins in throughput-heavy tasks. It is 25.3% ahead in Cinebench R15 multi-core, 19.7% ahead in PassMark multithread, and leads by 20.2% in integer math, 21.2% in floating point math, 22.5% in data compression, 28.9% in data encryption, 22.8% in extended instructions, 26.9% in random string sorting, and 49.2% in find prime numbers. Its 12 cores and 24 threads give it a natural advantage in parallel workloads. The unlocked multiplier also makes it attractive for users who want to tweak clocks, though the mobile socket limits its platform options.

In short: the EPYC 4345P is a single-thread monster with server-class features. The Ryzen 9 7845HX is a multi-thread workhorse with a core-count advantage. Choose the EPYC for latency-sensitive, single-threaded server duties and choose the Ryzen for parallel compute and throughput-centric mobile workloads.