Intel provided the hardware world with a thorough breakdown on Alder Lake at the chipmaker's Architecture Day 2021. However, Intel didn't touch on the topic of the integrated graphics that will accompany Alder Lake. Hardware detective Komachi_Ensaka has sniffed out a new coreboot patch that gives us a small look at the iGPUs inside the mobile Alder Lake chips.
It's important to note that Alder Lake-M isn't the best performing mobile chip in Intel's lineup. A previous coreboot update reportedly showed that Intel may segment mobile Alder Lake into four categories. The Alder Lake-M is at the bottom of the stack with a 9W TDP and a maximum configuration with two performance (Golden Cove) cores and eight efficiency (Gracemont) cores.
For Alder Lake, Intel ported the Gen12 Xe LP graphics engine from Tiger Lake to the new Intel 7 process. According to the latest code in coreboot, Intel may only stick with the GT1 unit for desktop Alder Lake-S processors. The GT1 solution wields 32 execution units (EUs), which are now called Vector Engines.
Alder Lake-M, however, could utilize up to three different iGPU solutions, depending on the model of the processor. The new coreboot references GT1, GT2 and GT3 units. We already know that GT1 is equipped with 32 EUs, which means that the GT2 and GT3 units should sport 96 EUs. The reasoning behind why the desktop Alder Lake processors only get the GT1 unit is because of the likelihood of consumers pairing the chips with discrete graphics cards.
Mentions of the GT3 engine in coreboot may signal the return of Intel's Iris graphics, which is basically the higher-end version of the normal HD graphics. This is different from the Iris Pro or Iris Plus variants, though. Remember that Intel historically referred to the Iris Pro and Iris Plus graphics under the GT3e moniker.
Intel will launch Alder Lake this Fall 2021. Nonetheless, the chipmaker didn't specify if it's releasing the desktop chips first with the mobile variants coming after or both in tandem. We will likely hear more about the heterogeneous processors at the Intel Innovation event, which the chipmaker is holding on October 27 and 28.