AMD EPYC 4584PX vs AMD Ryzen 9 9955HX3D Comparison

The AMD Ryzen 9 9955HX3D and AMD EPYC 4584PX are two 16-core, 32-thread processors that end up far closer in performance than their different market segments suggest. The Ryzen 9 9955HX3D, a mobile part built on Zen 5, edges out the server/workstation EPYC 4584PX, built on Zen 4, by a razor-thin 0.1% in average benchmark score. The data shows the Ryzen 9 9955HX3D wins 13 of the 17 head-to-head tests, but the EPYC 4584PX takes decisive victories in specific workloads like encryption and random string sorting. These are not chips competing for the same socket or system, but if you are choosing between them purely on benchmark data, the Ryzen 9 9955HX3D is the faster overall processor, while the EPYC 4584PX holds its own in specialized tasks.

The Verdict

The Ryzen 9 9955HX3D is the default pick for anyone who wants the highest possible multi-threaded and single-threaded performance in a mobile form factor. It leads in every Cinebench test, with a 1.8% advantage over the EPYC 4584PX in both R15 and R23 multi-core and single-core runs. Its average benchmark score of 86437 places it at the 98th percentile of all CPUs, one point higher than the EPYC 4584PX's 97th percentile. For workloads that stress floating-point math, prime number finding, extended instructions, or integer math, the Ryzen 9 9955HX3D is the clear winner, with deltas ranging from 3.6% to 14%.

The EPYC 4584PX is the pick when specific server-side tasks matter more than raw aggregate score. It wins data encryption by a massive 19.6% margin (47904 vs 38516) and random string sorting by 9.7% (90378 vs 81627). It also pulls a narrow 1.3% win in data compression and a negligible 0.1% lead in physics. If your workflow is dominated by encryption or sorting large datasets, the EPYC 4584PX is the better choice, despite being slightly behind in most other tests. Its launch MSRP is $699.

Architecture Differences

The two chips come from different Zen generations and manufacturing nodes. The Ryzen 9 9955HX3D uses the Zen 5 architecture on TSMC's 4 nm process, with a codename of Fire Range and a die size of 2x 70.6 mm² containing 16,630 million transistors. The EPYC 4584PX uses the older Zen 4 architecture on a 5 nm process, codenamed Raphael, with a die size of 2x 71 mm² and 17,840 million transistors. Despite having more transistors, the EPYC 4584PX trails in most benchmarks, indicating the Zen 5 architecture's efficiency advantage on the smaller node.

Cache configurations differ per core. The Ryzen 9 9955HX3D has 80 KB of L1 cache per core, while the EPYC 4584PX has 64 KB per core. Both share 1 MB of L2 per core and 128 MB of L3 cache. The EPYC 4584PX explicitly lists a "1x 64MB Slice" for its 3D V-Cache, while the Ryzen 9 9955HX3D's cache entry does not specify a separate V-Cache slice. The Ryzen 9 9955HX3D has a higher memory bandwidth at 89.6 GB/s versus 83.2 GB/s, though both support dual-channel DDR5 with ECC.

Clock speeds and power targets differ substantially. The EPYC 4584PX has a higher base clock of 4.20 GHz and boost clock of 5.70 GHz, but a 120W TDP. The Ryzen 9 9955HX3D runs at a 2.50 GHz base and 5.40 GHz boost, with a much lower 55W TDP. The Ryzen 9 9955HX3D is unlocked for overclocking, while the EPYC 4584PX is locked. Both use AMD Socket FL1 and AM5 respectively, with 28 PCIe Gen 5 lanes from the CPU. The Ryzen 9 9955HX3D integrates Radeon 610M graphics, while the EPYC 4584PX has generic Radeon Graphics.

FAQ

Q: Which processor has the higher average benchmark score?

A: The AMD Ryzen 9 9955HX3D has an average benchmark score of 86437, which is 0.1% higher than the AMD EPYC 4584PX's 86371.

Q: Is the EPYC 4584PX faster in any Cinebench test?

A: No. The Ryzen 9 9955HX3D wins every Cinebench R15, R20, and R23 multi-core and single-core test by a consistent 1.8% margin.

Q: How large is the EPYC 4584PX's lead in data encryption?

A: The EPYC 4584PX scores 47904 in PassMark data encryption, which is 19.6% higher than the Ryzen 9 9955HX3D's 38516.

Q: What are the TDP differences between the two?

A: The Ryzen 9 9955HX3D has a 55W TDP, while the EPYC 4584PX has a 120W TDP. The Ryzen 9 9955HX3D achieves higher multi-core scores despite the lower power envelope.

Q: Which chip has a higher boost clock?

A: The EPYC 4584PX boosts to 5.70 GHz, which is higher than the Ryzen 9 9955HX3D's 5.40 GHz boost clock.

Q: Do both processors support ECC memory?

A: Yes, both the Ryzen 9 9955HX3D and the EPYC 4584PX have ECC memory support enabled.

Specification Differences

• Architecture: Ryzen 9 9955HX3D is Zen 5; EPYC 4584PX is Zen 4.
• Process Node: Ryzen 9 9955HX3D is 4 nm; EPYC 4584PX is 5 nm.
• Codename: Ryzen 9 9955HX3D is Fire Range; EPYC 4584PX is Raphael.
• Transistors: Ryzen 9 9955HX3D has 16,630 million; EPYC 4584PX has 17,840 million.
• Die Size: Ryzen 9 9955HX3D is 2x 70.6 mm²; EPYC 4584PX is 2x 71 mm².
• Base Clock: Ryzen 9 9955HX3D is 2.50 GHz; EPYC 4584PX is 4.20 GHz.
• Boost Clock: Ryzen 9 9955HX3D is 5.40 GHz; EPYC 4584PX is 5.70 GHz.
• TDP: Ryzen 9 9955HX3D is 55W; EPYC 4584PX is 120W.
• L1 Cache: Ryzen 9 9955HX3D has 80 KB per core; EPYC 4584PX has 64 KB per core.
• Memory Bandwidth: Ryzen 9 9955HX3D is 89.6 GB/s; EPYC 4584PX is 83.2 GB/s.
• Socket: Ryzen 9 9955HX3D uses AMD Socket FL1; EPYC 4584PX uses AMD Socket AM5.
• Market Segment: Ryzen 9 9955HX3D is Mobile; EPYC 4584PX is Server/Workstation.
• Release Date: Ryzen 9 9955HX3D released 2025-01-05; EPYC 4584PX released 2024-05-20.
• Unlocked Multiplier: Ryzen 9 9955HX3D is unlocked; EPYC 4584PX is locked.
• Integrated Graphics: Ryzen 9 9955HX3D has Radeon 610M; EPYC 4584PX has Radeon Graphics.
• Part Number: Ryzen 9 9955HX3D is 100-000001030; EPYC 4584PX is 100-000001481.
• Percentile: Ryzen 9 9955HX3D is at 98th percentile; EPYC 4584PX is at 97th.

Head-to-Head Benchmarks

The Ryzen 9 9955HX3D dominates the Cinebench suite, winning all six tests by exactly 1.8%. In R15 multi-core, it scores 5289 against 5193 for the EPYC 4584PX. R15 single-core shows 746 vs 733. Moving to R20, the Ryzen 9 9955HX3D scores 22039 multi-core and 3111 single-core, versus 21640 and 3055 for the EPYC 4584PX. The R23 results follow the same pattern: 52475 vs 51524 multi-core and 7408 vs 7274 single-core.

In PassMark tests, the Ryzen 9 9955HX3D wins the math-heavy workloads. Floating-point math shows a 10.7% lead (140559 vs 126934). Find prime numbers is its biggest win at 14% (521 vs 457). Extended instructions bring an 8.1% advantage (60405 vs 55888). Integer math is closer, with a 3.6% lead (219084 vs 211410). Single-thread performance favors the Ryzen 9 9955HX3D by 12.9% (4492 vs 3977). The multithread test also goes to the Ryzen 9 9955HX3D, but by only 1.3% (61403 vs 60617).

The EPYC 4584PX takes four wins, with two being substantial. Data encryption is its standout victory at 19.6% (47904 vs 38516). Random string sorting shows a 9.7% lead (90378 vs 81627). Data compression is a narrower, 1.3% win (772693 vs 762606). Physics is essentially a tie, with the EPYC 4584PX leading by 0.1% (4659 vs 4653).

Where Each One Wins

The Ryzen 9 9955HX3D is the winner for general-purpose compute and any workload that relies on Cinebench-style rendering or single-threaded performance. Its consistent 1.8% edge across all Cinebench versions makes it the better choice for 3D rendering, video encoding, and applications that scale with multi-core CPU performance. The 12.9% lead in PassMark single-thread means everyday desktop responsiveness and lightly-threaded applications will feel snappier on the Ryzen 9 9955HX3D. Its 10.7% advantage in floating-point math and 14% in prime number finding also make it the pick for scientific computing and numerical analysis. The lower 55W TDP is a significant practical advantage for mobile systems, delivering higher performance at less than half the power draw of the EPYC 4584PX.

The EPYC 4584PX is the winner only in a narrow set of server-oriented tasks. The 19.6% lead in data encryption makes it the clear choice for security-focused workloads, VPN gateways, or database encryption operations. The 9.7% win in random string sorting suggests better performance in sorting algorithms, which could benefit certain database or data-processing pipelines. Its 1.3% edge in data compression is small but consistent, making it marginally better for compression workloads like backup systems or file archiving. The physics test is a dead heat, so neither chip offers a meaningful advantage there. For anyone building a server where encryption or sorting is the primary bottleneck, the EPYC 4584PX is the better part, despite its overall lower aggregate score.