Intel Shows off Granite Rapids and Sierra Forest Packages

Intel posted a video on its packaging technologies, and in it, appear to be the company’s 2024 server CPUs codenamed Granite Rapids and Sierra Forest. Intel did not label them as such, but given the recent disclosures, it feels like these are the next-generation Xeon packages.

Intel Shows off Granite Rapids Packages

First, we get a fairly clear shot of the Granite Rapids package in someone’s hand. This appears to be an in-progress package. The top and bottom slimmer dies are the I/O dies. The three middle tiles are the compute dies with memory controllers.

Here is another look at these.

At Hot Chips 35, we got to see the Granite Rapids package with the heat spreader, but not this level of detail under the heat spreader.

Although it was not labeled in the video, it was fairly clear what this one is given Intel’s previous disclosures.

Next, was the new one.

Intel Sierra Forest Package Shown?

As part of the packaging video, there is a set of chips being manufactured. These chips have the two I/O dies on either end but have a single larger compute tile in the middle.

It turns out that Intel showed this during Hot Chips 2023 in its presentation we covered in Intel on Changing its Xeon CPU Architecture at Hot Chips 2023. That package looks a lot like the bottom right package in the slide below.

There were comments made about a single compute tile Sierra Forest at Hot Chips. Here we can see a very different design with one big compute chiplet and two I/O chiplets. Notable here is that the diagram above has eight DDR5 memory channels.

If an E-core was significantly smaller than a P-core, and Intel was focused on providing fairness across the CPU for cloud customers, then this makes sense. A single compute die with E-cores would use lower power. It could also be a lower core count P-core part pictured, but then Intel would have two P-core compute tiles somewhat defeating the purpose of modularity versus the two compute tile and two I/O tile design. This one feels like it meshes with Sierra Forest.

Final Words

The Granite Rapids one feels like it is certainly the package for the higher-core count P-core CPU. The second chip looks like the 8-channel memory single compute tile version that is also on Intel’s modular SoC architecture slide. That also seems to intersect with what we know about Sierra Forest. Perhaps that design is focused on hyper-scale power and thread fairness/ performance requirements and is how Intel is going to achieve a lower power design.

We saw a next-gen PCH-Less Intel Granite Rapids Motherboard with 8-channel memory at Computex 2023 so it feels like we are seeing more on this platform.