AMD EPYC 7251 vs AMD Ryzen 9 4900H Comparison

Head-to-Head Benchmarks

The benchmark data splits cleanly between the two processors, with each taking two of the four shared test categories. In Cinebench R15 multicore, the AMD Ryzen 9 4900H posts 1926.5 against the AMD EPYC 7251's 1279, a 50.6% advantage. That is the largest single gap in the head-to-head set, and it reflects the mobile chip's clear dominance in that specific workload. The single-core R15 result is closer: 193 for the Ryzen 9 4900H versus 180 for the EPYC 7251, a 7.2% edge. So in the older Cinebench version, the 4900H wins both multicore and single-core tests.

The picture reverses in Cinebench R23. The EPYC 7251 scores 12694 multicore, beating the Ryzen 9 4900H's 11604 by 8.6%. The single-core gap is even larger: 1792 for the EPYC 7251 versus 1294 for the Ryzen 9 4900H, a 27.8% difference. That is a notable swing, since the Ryzen 9 4900H has a much higher boost clock in its specification. The newer benchmark clearly favors the server part.

Looking at average benchmark scores, the Ryzen 9 4900H averages 3820, while the EPYC 7251 averages 3671. Both sit at the 56th percentile of all CPUs in the database. The nearest rivals for the Ryzen 9 4900H are the Intel Xeon E-2286M at 3822 (0.1% ahead), the Intel Core i7-8086K at 3800 (0.5% behind), the Intel Core i7-9700KF at 3787 (0.9% behind), and the AMD Ryzen 7 PRO 2700 at 3777 (1.1% behind). The EPYC 7251's closest competitors include the AMD Ryzen 7 PRO 1700X at 3673 (0.1% ahead), the Intel Core i3-13100E at 3668 (0.1% behind), the Intel Xeon E5-2658A v3 at 3658 (0.4% behind), and the AMD EPYC 7301 at 3685 (0.4% ahead). The two chips effectively trade blows within their own peer groups.

Architecture Differences

The AMD Ryzen 9 4900H is built on Zen 2 with the Renoir codename, part of the 4000 series for mobile. It uses a 7 nm process from TSMC, with 9,800 million transistors on a 156 mm² die. The AMD EPYC 7251 belongs to the EPYC 7001 series with the Naples codename, using the original Zen architecture on a 14 nm process from GlobalFoundries, with 4,800 million transistors and a 213 mm² die. The node difference is substantial, and it explains much of the power and efficiency contrast between the two.

Cache layouts differ considerably. The Ryzen 9 4900H has 64 KB of L1 per core, 512 KB of L2 per core, and 8 MB of shared L3. The EPYC 7251 has 96 KB of L1 per core, 512 KB of L2 per core, and 32 MB of shared L3. The server chip carries four times the L3 cache, which matters for workloads with large working sets.

Memory support is another major split. The Ryzen 9 4900H supports DDR4 and LPDDR4 over a dual-channel bus with 51.2 GB/s of bandwidth. The EPYC 7251 supports DDR4 over an eight-channel bus with 153.6 GB/s of bandwidth. That is three times the memory bandwidth for the EPYC, a typical server advantage. The 4900H does not support ECC memory, while the EPYC 7251 does. Both use PCIe Gen 3.

The Ryzen 9 4900H includes integrated Radeon Graphics with 512 SPs, while the EPYC 7251 has no integrated graphics at all. The EPYC 7251 uses the AMD Socket SP3, and its multiplier is unlocked. The Ryzen 9 4900H uses AMD Socket FP6 and has a locked multiplier. The 4900H is classified as a mobile part, while the EPYC 7251 is a server or workstation part. Both are listed as active in production.

FAQ

Q: Which processor has the higher boost clock?

A: The AMD Ryzen 9 4900H boosts to 4.40 GHz, while the AMD EPYC 7251 boosts to 2.90 GHz. The base clocks are 3.30 GHz and 2.10 GHz respectively.

Q: Why does the EPYC 7251 win Cinebench R23 despite having lower clock speeds?

A: The recorded data shows the EPYC 7251 scoring 12694 in R23 multicore and 1792 in R23 single-core, against 11604 and 1294 for the Ryzen 9 4900H. The EPYC's larger 32 MB shared L3 cache and eight-channel memory configuration likely contribute to its performance in that benchmark, though the database does not isolate the exact cause.

Q: Which chip supports ECC memory?

A: The AMD EPYC 7251 supports ECC memory. The AMD Ryzen 9 4900H does not.

Q: How do the memory bandwidth figures compare?

A: The EPYC 7251 has 153.6 GB/s of memory bandwidth over an eight-channel bus. The Ryzen 9 4900H has 51.2 GB/s over a dual-channel bus. That is a threefold difference.

Q: Do both processors have the same core and thread counts?

A: Yes. Both have 8 cores and 16 threads.

Q: What are the production statuses?

A: Both the AMD Ryzen 9 4900H and the AMD EPYC 7251 are listed as active in production.

Specification Differences

The two processors share core and thread counts, both offering 8 cores and 16 threads, but nearly everything else differs.

Clock speeds: the Ryzen 9 4900H runs at 3.30 GHz base and 4.40 GHz boost. The EPYC 7251 runs at 2.10 GHz base and 2.90 GHz boost.

TDP: the Ryzen 9 4900H is rated at 54 watts, while the EPYC 7251 is rated at 120 watts.

Socket: the Ryzen 9 4900H uses AMD Socket FP6, the EPYC 7251 uses AMD Socket SP3.

Architecture: the Ryzen 9 4900H is Zen 2 with the Renoir codename. The EPYC 7251 is Zen with the Naples codename.

Process node: the Ryzen 9 4900H is on 7 nm from TSMC. The EPYC 7251 is on 14 nm from GlobalFoundries.

Transistors: the Ryzen 9 4900H has 9,800 million, the EPYC 7251 has 4,800 million.

Die size: the Ryzen 9 4900H measures 156 mm², the EPYC 7251 measures 213 mm².

Cache: the Ryzen 9 4900H has 64 KB of L1 per core, 512 KB of L2 per core, and 8 MB of shared L3. The EPYC 7251 has 96 KB of L1 per core, 512 KB of L2 per core, and 32 MB of shared L3.

Memory support: the Ryzen 9 4900H supports DDR4 and LPDDR4 with dual-channel memory and 51.2 GB/s bandwidth, no ECC. The EPYC 7251 supports DDR4 with eight-channel memory and 153.6 GB/s bandwidth, with ECC.

Integrated graphics: the Ryzen 9 4900H includes Radeon Graphics 512SP. The EPYC 7251 has none.

Market segment: the Ryzen 9 4900H is mobile, the EPYC 7251 is server or workstation.

Multiplier: the Ryzen 9 4900H is locked, the EPYC 7251 is unlocked.

Release date: the Ryzen 9 4900H released on 2020-03-15, the EPYC 7251 on 2017-06-28.

The Verdict

The data supports a straightforward split. If the workload is built around the Cinebench R15 suite, the AMD Ryzen 9 4900H is the clear choice, with a 50.6% multicore lead and a 7.2% single-core lead. If the workload leans on Cinebench R23, the AMD EPYC 7251 wins by 8.6% multicore and 27.8% single-core. The average benchmark scores put the Ryzen 9 4900H slightly ahead at 3820 versus 3671, but both sit at the same 56th percentile, meaning they occupy the same overall performance tier in the database.

The choice should be driven by the environment. The Ryzen 9 4900H is a mobile part with integrated graphics, a 54 watt TDP, and dual-channel memory. It makes sense for systems where power draw and space are constrained, and where the integrated graphics remove the need for a separate GPU. The EPYC 7251 is a server part with ECC memory support, eight-channel memory, 153.6 GB/s of bandwidth, and an unlocked multiplier. It makes sense for servers or workstations where memory bandwidth, cache capacity, and ECC reliability matter more than clock speed.

Neither chip is a universal winner. The Ryzen 9 4900H dominates the older benchmark, the EPYC 7251 dominates the newer one. Their average scores are close, and their percentiles are identical. Buyers should match the chip to the workload, not to the brand.

Where Each One Wins

The AMD Ryzen 9 4900H wins in scenarios that favor its higher clocks and newer architecture. Its 4.40 GHz boost clock, 7 nm process, and 54 watt TDP make it the stronger candidate for mobile or compact systems. The Cinebench R15 results reinforce this: a 50.6% multicore lead and a 7.2% single-core lead over the EPYC 7251. The integrated Radeon Graphics 512SP also means it can handle display output without a discrete GPU. For general desktop-style workloads, or for anyone building a smaller system where the 4900H's lower power envelope and integrated graphics are assets, the data points to the 4900H.

The AMD EPYC 7251 wins in server and workstation contexts. Its 32 MB of shared L3 cache is four times that of the 4900H, and its eight-channel memory bus delivers 153.6 GB/s, three times the bandwidth. ECC memory support adds reliability for long-running or error-sensitive workloads. The unlocked multiplier gives overclocking room that the 4900H lacks. In Cinebench R23, the EPYC 7251 leads by 8.6% multicore and 27.8% single-core. Its 120 watt TDP and SP3 socket point to a platform designed for sustained all-core operation, not power-limited mobile use. For anyone assembling a server or workstation that needs large caches, high memory bandwidth, and ECC support, the EPYC 7251 is the better fit according to the recorded measurements.

The database shows two processors with equal core counts and equal overall percentiles, but very different strengths. The Ryzen 9 4900H is the mobile and general-purpose option, the EPYC 7251 is the memory-heavy and server option. The benchmark wins line up with those roles.