AMD Ryzen 7 8700G vs AMD Ryzen 9 3900XT Comparison

The AMD Ryzen 9 3900XT and the AMD Ryzen 7 8700G represent two distinct philosophies from the same manufacturer. The 3900XT is a 2020-era 12-core powerhouse built on the Zen 2 architecture, while the 8700G is a 2024-era 8-core processor using the much newer Zen 4 design. The recorded data shows a fascinating split: the older chip wins on raw multi-threaded throughput, while the newer chip dominates in single-thread performance and efficiency. The benchmark results paint a picture of two processors optimized for entirely different workloads.

Head-to-Head Benchmarks

The most striking result in the database is the Cinebench R23 single-core test. The 3900XT scores 3909, while the 8700G scores 1817, giving the 3900XT a massive 115.1% lead. This is an outlier compared to other single-thread tests, where the 8700G typically wins. For example, in 3dMark single-thread, the 8700G scores 1010 against 735 for the 3900XT, a 27.2% advantage.

In multi-threaded workloads, the 3900XT asserts its dominance. The Cinebench R23 multi-core test shows the 3900XT scoring 27688 against 17128 for the 8700G, a 61.7% lead. This is the largest multi-thread delta in the head-to-head data. Similarly, in 3dMark max threads, the 3900XT scores 8515 versus 7917, a 7.6% win.

The 8700G counters with strong showings in other multi-thread tests. In Geekbench multi-core, the 8700G scores 14584 against 11329 for the 3900XT, a 22.3% advantage. The 8700G also wins in 3dMark 16 threads (7918 vs 7537, a 4.8% lead) and 3dMark 8 threads (6589 vs 5200, a 21.1% lead).

The PassMark suite reveals a mixed bag. The 3900XT wins in data compression (452328 vs 386811, a 16.9% lead), data encryption (28634 vs 22842, a 25.4% lead), and find prime numbers (214 vs 103, a 107.8% lead). The 8700G takes floating point math (63815 vs 58513, an 8.3% lead) and integer math (103107 vs 99722, a 3.3% lead).

The overall win count is close: the 3900XT wins 11 benchmarks, while the 8700G wins 12. The average benchmark scores reflect this: the 3900XT averages 33736, while the 8700G averages 33089. The 3900XT sits at the 84th percentile of all CPUs, while the 8700G sits at the 83rd.

Architecture Differences

The two processors come from different eras of AMD design. The 3900XT uses the Zen 2 architecture on the Matisse 2 codename, built on a 7 nm process at TSMC. The 8700G uses Zen 4 on the Phoenix codename, built on a 4 nm process, also at TSMC. This process shrink is significant, as the 8700G packs 25,000 million transistors into a 178 mm² die, while the 3900XT uses 7,600 million transistors across two 74 mm² dies.

The core configurations differ substantially. The 3900XT has 12 cores and 24 threads, while the 8700G has 8 cores and 16 threads. Cache layouts are also distinct. The 3900XT features 64 MB of L3 cache, while the 8700G has 16 MB of shared L3. Both have 64 KB of L1 per core, but the L2 cache differs: 512 KB per core on the 3900XT versus 1 MB per core on the 8700G.

Clock speeds favor the newer chip. The 8700G has a base clock of 4.20 GHz and a boost clock of 5.10 GHz. The 3900XT has a base clock of 3.90 GHz and a boost clock of 4.70 GHz. The 8700G also carries a much lower TDP of 65 watts versus 105 watts for the 3900XT.

Memory support and platform details also diverge. The 3900XT supports DDR4 with dual-channel memory and a bandwidth of 51.2 GB/s. The 8700G supports DDR5 with dual-channel memory and a bandwidth of 83.2 GB/s. The 3900XT uses the AMD Socket AM4, while the 8700G uses the AMD Socket AM5. The 8700G includes integrated Radeon 780M graphics, while the 3900XT has no integrated graphics. PCIe lanes differ as well: 24 lanes on the 3900XT versus 20 lanes on the 8700G, both Gen 4.

Where Each One Wins

The data clearly shows the 3900XT is the champion of heavily multi-threaded, content-creation tasks. Its 61.7% lead in Cinebench R23 multi-core and 107.8% lead in PassMark find prime numbers suggest workloads like video rendering, 3D modeling, and scientific computing benefit greatly from its 12 cores and 24 threads. The 25.4% lead in data encryption and 16.9% lead in data compression point to strengths in file archiving and security-related processing.

The 8700G wins in most light-threaded and mixed workloads. Its 29.8% lead in Geekbench single-core and 27.2% lead in 3dMark single-thread indicate superior responsiveness in everyday tasks like web browsing, office applications, and light coding. The 22.3% lead in Geekbench multi-core, despite having fewer cores, suggests its Zen 4 architecture is more efficient per thread. The 8.3% lead in floating point math and 3.3% lead in integer math show it handles mathematical operations better.

The 8700G's integrated Radeon 780M graphics make it a clear choice for systems without a discrete GPU. The 3900XT requires a separate graphics card, but its higher multi-thread scores make it the better option for users who already have a dedicated GPU and prioritize CPU-heavy tasks. The 8700G's lower TDP of 65 watts versus 105 watts suggests it is better suited for compact or power-conscious builds.

FAQ

Q: Which processor has a higher single-core score in Geekbench?

A: The AMD Ryzen 7 8700G scores 2337 in Geekbench single-core, while the AMD Ryzen 9 3900XT scores 1640, giving the 8700G a 29.8% lead.

Q: How does the 3900XT perform in Cinebench R23 multi-core compared to the 8700G?

A: The 3900XT scores 27688 in Cinebench R23 multi-core, while the 8700G scores 17128, resulting in a 61.7% advantage for the 3900XT.

Q: What is the difference in L3 cache between the two processors?

A: The 3900XT has 64 MB of L3 cache, while the 8700G has 16 MB of shared L3 cache.

Q: Does the 8700G have integrated graphics?

A: Yes, the 8700G includes Radeon 780M integrated graphics. The 3900XT does not have integrated graphics.

Q: Which processor has a higher boost clock?

A: The 8700G has a boost clock of 5.10 GHz, while the 3900XT has a boost clock of 4.70 GHz.

Q: What memory types do these processors support?

A: The 3900XT supports DDR4 memory, while the 8700G supports DDR5 memory.

Specification Differences

The two processors differ on nearly every core specification. The 3900XT has 12 cores and 24 threads, while the 8700G has 8 cores and 16 threads. Base clocks are 3.90 GHz for the 3900XT and 4.20 GHz for the 8700G. Boost clocks are 4.70 GHz and 5.10 GHz respectively. The TDP is 105 watts for the 3900XT and 65 watts for the 8700G.

The socket types are different: AM4 for the 3900XT and AM5 for the 8700G. Process nodes are 7 nm for the 3900XT and 4 nm for the 8700G. Transistor counts are 7,600 million for the 3900XT and 25,000 million for the 8700G. Die sizes are 2x 74 mm² for the 3900XT and 178 mm² for the 8700G.

Cache configurations differ in L2 and L3. The 3900XT has 512 KB of L2 per core, while the 8700G has 1 MB per core. L3 is 64 MB for the 3900XT versus 16 MB shared for the 8700G. Memory support is DDR4 for the 3900XT and DDR5 for the 8700G. Memory bandwidth is 51.2 GB/s for the 3900XT and 83.2 GB/s for the 8700G. PCIe lanes are 24 for the 3900XT and 20 for the 8700G, both Gen 4.

The architectures are Zen 2 with the Matisse 2 codename for the 3900XT, and Zen 4 with the Phoenix codename for the 8700G. The 8700G has integrated Radeon 780M graphics, while the 3900XT has none. Release dates are July 6, 2020 for the 3900XT and January 7, 2024 for the 8700G.

The Verdict

The data indicates a clear split based on workload priorities. The AMD Ryzen 9 3900XT is the choice for users who need maximum multi-threaded performance. Its 12 cores and 24 threads deliver a 61.7% lead in Cinebench R23 multi-core and a 107.8% lead in PassMark find prime numbers. It also leads in data compression, encryption, and random string sorting. The 3900XT's 84th percentile ranking versus the 8700G's 83rd percentile reflects its slightly higher average benchmark score of 33736 versus 33089.

The AMD Ryzen 7 8700G is the better option for users prioritizing single-thread performance, power efficiency, and integrated graphics. It wins in 3dMark single-thread (27.2% lead), Geekbench single-core (29.8% lead), and PassMark single-thread (30.2% lead). Its 65 watt TDP is significantly lower than the 3900XT's 105 watts. The Radeon 780M integrated graphics eliminate the need for a discrete GPU in basic systems.

For users with a dedicated graphics card and heavy rendering workloads, the 3900XT's multi-thread dominance makes it the logical choice. For users building a compact system without a discrete GPU, or those who prioritize fast single-thread response and lower power draw, the 8700G is clearly superior. The 8700G also benefits from DDR5 memory support and a newer platform with AM5. The 3900XT's launch MSRP was $499, while the 8700G's launch MSRP was $329.