The 7800X3D is truly divine, offering the gaming performance of an i9, and the productivity performance of an i5, all while being priced like an i7. It’s incredibly cost-effective for those who prioritize gaming over office work, and it also has a very low power consumption. Why can’t Intel produce CPUs with a 3D cache?
3D cache technology was handed down from AMD’s server technology, with AMD’s server CPUs outperforming Intel’s significantly. Even with double the power consumption, Intel can’t match AMD’s multi-core performance.
However, the 3D stacked cache is not without its drawbacks. Stacking the cache on top of the CPU reduces heat dissipation efficiency, leading to overheating issues.
Overall, the 7800X3D is not quite mature yet. We’ll have to wait and see how AMD optimizes it in the next generation.
Wonder if AMD has patented the 3D V-Cache technology.
Furthermore, the 7800X3D is not just an enhancement for ZEN4 but a vital improvement.
The physical separation of CCD and IOD inherently puts ZEN4’s memory performance significantly behind its competitors. Coupled with lower IPC and frequency, ZEN4‘s gaming performance is definitively worse than contemporary RPL-S.
The idea behind 7800X3D is, “Since I can’t win in memory performance anyway, I might as well make memory less important.“
By using a massive amount of L3 cache to increase cache hit rates, it reduces the frequency of direct memory reads by the CPU, thereby improving gaming performance. However, this new technology has clear drawbacks. Stacking an L3 layer on the cores is like adding a blanket, trapping heat within the silicon, which can cause issues, thus requiring a reduction in frequency and voltage. In some cache-insensitive games, you might even see the 7800X3D perform worse than the 7700X.
The drawbacks of 3D technology are clear: high idle power consumption and overheating. However, these issues are not apparent in servers, which operate at low frequencies for extended periods, where low frequency reduces heat, and continuous operation disregards idle power. This contrasts with individual users who benefit from low idle power and high operational power, making this technology less suitable for personal use. Since the Zen1 era, AMD has dominated the server market with the introduction of Zen2, and future software may adapt to use big.LITTLE architecture, but not yet.
The cache stacking uses TSMC’s 3D packaging technology, while Intel has its 3D packaging technology. The issue for Intel is its monolithic chip design, which would be affected by adding a cache layer, making 3D cache unfeasible for mobile APUs. However, Intel plans to include an L4 cache in the base tile, which can exceed the capacity and bandwidth of L3 while minimally affecting the thermal dissipation of the upper layers. Therefore, the difference is purely in design, not related to patents or the ability to implement the technology. TSMC would not exclusively provide 3D packaging to one company nor prevent Intel from using its 3D packaging technology.
