Intel Granite Rapids & Sierra Forest Xeon CPU Detailed In Avenue City Platform Leak: Up To 500W TDP & 12-Channel DDR5

Platform details of Intel's Avenue City platform which will be supporting the next-gen Granite Rapids & Sierra Forest-AP Xeon CPUs have been leaked.

The information was leaked within two slides posted by YuuKi_AnS and gives us a look at what the next generation of Xeon platforms has to offer. For now, Intel has its Eagle Stream platform that is going to support the existing Sapphire Rapids-SP and upcoming Emerald Rapids-SP CPUs. This CPU platform is based around the LGA 4677 socket. For the next iteration of Xeon chips, Intel will have a new Mountain Stream and Birch Stream platform. The Birch Stream platform will be designed for a high-end series of Xeon chips including Granite Rapids-AP and Siera Forest AP and we have our first good look at what the reference Avenue City platform has to offer.

Starting with the details, the reference Avenue City motherboard features a 16.7" x 20" design with 20 PCB layers. The CPUs come with a 13-layer package. The reference platform houses two massive LGA 7529 sockets that feature support for Granite Rapids and Sierra Forest-AP CPUs with up to 500 Watt TDP support. The platform comes with a total of 24 DDR5 DIMMs with support for 12-channel memory, 6 PCIe Gen 5 x16 links (Gen5/CXL), and 6x24 UPI links. The Granite Rapids-AP CPUs will be featuring up to 128 cores and 256 threads and will come in HBM flavors as ES/ engineering samples have shown.

Talking about the memory itself, the 24 DDR5 DIMM slots support up to 6400 Mbps speeds in 1DPC configurations and up to 8000 Mbps with MCR (Multiplexer Combined Ranks). Intel did demo its next-gen Xeon CPUs running DDR5-6400 memory last year and that's exactly what the Granite Rapids family is going to utilize.

Other features of the Avenue City reference platform include two PCIe x2 M.2 slots, 1 PCIe x2 M.2 (2280) Module, and a PCIe x1 LOM (Springville). The board has a host of I/O such as rear USB 3.0 + USB 2.0 ports, Serial Port (Type-C), Mini DP, a Gigabit Ethernet switch for management, a RunBCM Module (AST2600), and for security, the motherboard comes with TPM 2.0, SPI TOM Module conn and PFR 4.0.

Intel also lists down the chassis which support a motherboard like this with one being a 2S Open CHassis Standard EGS POK and the other being a 2S 4U closed chassis (Rich AIC). Intel asks users installing a Granite Rapids or Siera Forest Xeon CPU within this motherboard to wear ESD gloves which should prevent oxidation or foreign material on package lands. We have already got a look at the massive LGA 7529 socket which measures the full length of the DDR5 slot.

Now the thing about Avenue City is that it is part of the Birch Stream platform &  not the Mountain Stream platform. In fact, we haven't heard a lot about the Mountain Stream platform but what we do know is that Granite Rapids is going to be the standard P-Core parts that are expected to put the latest Redwood Cove cores based on the Intel 4 process node to use whereas the Sierra Forest chips are going to be an all E-Core design with loads of cores for compute/efficiency density that is going to be used against AMD's Bergamo lineup which also utilizes a compute/efficiency targetted Zen 4C design.

The Intel Granite Rapids Xeon CPUs are expected to launch by the end of next year (if things go smoothly) and Sierra Forest is also expected around the same time but we can't say for sure as Intel had a rocky launch of Sapphire Rapids which got delayed immensely. We will see if Intel can deliver its Emerald Rapids-SP CPUs on time and boost customer confidence in achieving a more timely launch of its Xeon products.