Review: Ryzen 7 5800X3D is an interesting tech demo that’s hard to recommend

AMD’s AM4 socket has had a protracted and profitable run on the desktop, ushering within the Ryzen processor lineup and serving to AMD compete with and outperform Intel’s chips for the primary time for the reason that mid-2000s.

The getting older socket’s time is coming to a detailed later this 12 months when the Ryzen 7000-series chips are launched, however AMD is sending it off with one final high-performance processor: the Ryzen 7 5800X3D, which launches on April twentieth for $449.

AMD makes use of a novel packaging know-how known as “3D V-Cache” to triple the quantity of L3 cache on the processor, from 32MB for the usual Ryzen 5800X to a whopping 96MB. This new tech appears like an experiment in some methods. In contrast to different Ryzen CPUs, the 5800X3D would not provide overclocking or energy consumption controls, and its clock speeds are a bit decrease than the usual 5800X. However AMD says that the additional cache permits the 5800X3D to outrun Intel’s quickest CPUs in terms of gaming.

We have run some checks on the 5800X3D to seek out its strengths and weaknesses and to get a way of if you’ll discover the affect of the extra cache. That is undoubtedly an fascinating processor, however its pricing and very particular efficiency benefits will restrict it to a distinct segment of a distinct segment.

3D V-Cache, in short

Architecturally, nothing in regards to the Zen 3 cores that energy the 5800X3D has modified in comparison with the vanilla 5800X. We’re nonetheless speaking about an 8-core, 16-thread core complicated die (CCD) constructed on TSMC’s 7 nm course of, with its 32MB of L3 cache intact. Simply as Apple bulit interconnect help into the M1 Max to help the M1 Extremely, AMD created Zen 3 to help 3D V-Cache know-how each time it was able to ship.

The principle change is that AMD and TSMC have lowered the bodily top of the CCD die so {that a} CPU package deal with 3D V-Cache received’t should be bodily taller than a CPU package deal with out it. This adjustment preserves compatibility with current CPU coolers.

The 64MB of further L3 cache, additionally constructed on TSMC’s 7 nm course of, is bodily stacked on the Zen 3 CCD and related with direct copper-to-copper bonding. The result’s one thing that the system sees as one massive pool of L3 cache that may all be handled the identical—the 64MB of stacked cache isn’t an L4 cache, and the 32MB of L3 cache constructed into the CCD doesn’t have any efficiency benefit in comparison with the cache stacked on high.

One aspect impact of this packaging know-how is that the 5800X3D runs at a noticeably slower clock pace than the 5800X, and AMD doesn’t formally permit any overclocking or energy changes when utilizing the 5800X3D. AMD is pushing the 5800X3D primarily as a gaming processor, and that’s as a result of video games profit extra constantly from having a much bigger pool of cache to play with. For workloads that care much less about cache and extra about clock pace—as we’ll see once we begin benchmarking—the 5800X3D could be slower than the common 5800X, which AMD freely admits.

AMD performed coy about whether or not we may anticipate future Zen 3 CPUs with 3D V-Cache enabled, however studying between the traces, it appears unlikely. 3D V-Cache will probably be one of many instruments in AMD’s toolbox in terms of boosting efficiency for Zen 4 and the primary Socket AM5 platforms—together with a 5nm TSMC course of, DDR5 help, and different architectural enhancements—however I don’t get the sense that the 5800X3D will probably be adopted up with an expanded lineup of Zen 3-based X3D chips.

AMD says that motherboards will want a BIOS replace to see and use the additional 64MB of cache—search for AGESA model 1.2.0.6b or increased within the launch notes. Motherboards that help different Ryzen 5000 CPUs will work with the 5800X3D, however they received’t be capable of entry the additional cache, defeating the aim of spending extra money on the CPU within the first place.