South Korean tech treasure hunter The dream of the coelacanth (opens in a new tab) dug up some interesting tidbits about the integrated GPU that comes with Intel Meteor Lake processors. Based on sightings of new code patches for the Intel Graphics Compiler (IGC), the sleazy tech poster revealed that Meteor Lake iGPUs could support ray tracing in hardware. Unfortunately, a potential downside is that the iGPU may run out of Intel XMX (Xe Matrix eXtension) units.
Intel’s 13th generation Core processors, codenamed Raptor Lake (RPL), are next – and should arrive very soon. However, in 2023, we believe 14th Gen Intel Core processors, dubbed Meteor Lake (MTL), will cause a stir with several bold, advanced moves. Regular readers will know that the transition from 13th to 14th Gen Core processors will be from Intel 7 to Intel 4. That’s not all, however, as we’ll see Intel’s first disaggregated design with a TSMC N3 tile under the heat sink. This will be the GPU part of the chip, and thanks to the detective work of people like Coelacanth’s Dream, we have an ever clearer picture of this iGPU.
In July this year, Coelacanth’s Dream discovered Intel Linux patches, suggesting that MTL’s graphics tile would feature the Xe-HPG/Xe-LPG architecture and up to 128 EUs produced by TSMC using its manufacturing N3. We now have in mind the new code fixes for the Intel Graphics Compiler (opens in a new tab)(IGC), further inferences can be made regarding the GPU tile.
Most interesting is probably the patch flag that suggests the Meteor Lake iGPU will have ray tracing hardware. Intel LGA1700 processors, like Alder Lake and Raptor Lake, come with up to 96 EU Xe-LPs. However, Meteor Lake will have a Xe-HPG architecture GPU with more in common with Alchemist/DG2 discrete graphics cards and could feature up to 128 or even 192 of these EUs. The ray tracing support feature has been carried over to IGC, where it enables ray tracing support if iGFX_meteorlake is detected. Additionally, Meteor Lake also appears to support hardware ray tracing in any application that supports Alchemist/DG2 or Ponte Vecchio functionality.
Adding ray-tracing support to its iGPUs is a welcome move by Intel, but it will only catch up with AMD, which released its Ryzen 6000 (Rembrandt) processors with RDNA2 iGPUs for the major part of 2022.
Now let’s move on to the problem of the lack of XMX units in Meteor Lake’s iGPU architecture. It is observed through the IGC patches that MTL does not support Dot Product Accumulate Systolic (DPAS) instructions that rely on XMX units. This hints that the iGPU lacks XMX units, which could negatively impact Intel XeSS acceleration, for example. On the desktop, an Xe-core has 16 XMX units that can perform 128 FP16/BF16, 256 INT8, or 512 INT4/INT2 operations per clock. They also accelerate XeSS, but this scaling technology has a fallback to DP4a instruction mode.
Finally, it should be remembered that the Meteor Lake processors represent a rather significant change for Intel and may experience problems starting. About a fortnight ago, we reported that the production of Meteor Lake 3nm GPU tiles at TSMC might have been postponed. Intel may have decided to move to the new N3E process, but it’s hard to tell from sources if that’s indeed the case or if problems are brewing.