Zen 4 On AM4 May Not Happen But We Might Get A Monster Ryzen 9 5900X3D Gaming CPU

AMD EPYC Milan X Die Shot
Regular HH readers may recall that Saturday before last, we reported on a rumor regarding the existence of processors based on Zen 4 CPU cores that slot into extant AM4 motherboards. Frequent leaker Greymon55 suggested that such a thing is possible, but admitted that he wasn't sure of the veracity of the information.

In part, we're responsible for this rumor. Speaking to us on YouTube, AMD's Robert Hallock said that AMD's sockets, AM4 and AM5, are to "co-exist," and that AM4 "has a lot of life." However, he also did say that while there may still be more CPUs for AM4, "nothing specifically is planned right now." Speaking to Forbes, he was a little more direct. Forbes' Antony Leather asked Hallock if the 5800X3D was the last processor for AM4, and Hallock said "probably not."

Robert Hallock speaking to Forbes.

Well, Hungarian site ProHardver! was tired of the rumors, apparently, and went straight to the source: motherboard vendors. The site doesn't elaborate which vendors it spoke with, but according to ProHardver!, no such product is on the way. The site says that such a construction—Zen 4 on AM4—would be very difficult because the AM5 socket is an LGA with a lower bottom height, yet the same top height as AM4's PGA socket. The chiplets are apparently designed to make use of this extra vertical space, and so they will not fit in an AM4 package.

ProHardver! goes on to mention that, according to the companies it spoke with, there is another product on the way for Socket AM4, but that it's another Zen 3 design with 3D V-Cache. The processor in question would surely be known as the Ryzen 9 5900X3D, which is to say that it is purportedly a twelve-core processor using two CCDs, each topped with their own 64MB 3D V-Cache chiplet.

AMD EPYC Milan X Delidded
Like this, but smaller and with only two dice. So not really like this.

That would give the chip a total of 192 MB of L3 cache and certainly make it a monster for gaming, but we have to wonder about the cost-benefit analysis of such a processor. As we saw in our review of the processor as well as our review of the Falcon Northwest Tiki that came strapped with it, the Ryzen 7 5800X3D gives killer performance for gaming, but productivity tasks—traditionally the thing that you use many-core CPUs for—don't gain much at all. We suppose we'll see if AMD springs it on us.