Core Ultra K prototype appears on CPU-Z, uses Intel 4 process node and hits 5 GHz, lacks AVX-512 support

A mysterious Core Ultra K series engineering sample has made an appearance on CPU-Z. Алексей on X (Twitter) a screenshot of the mysterious part, with many of the critical system specifications blanked out to hide its true identity. Among the interesting findings is that the chip is listed with a 7nm node, denoting it uses the Intel 4 process, and lacks support for AVX-512.

The specs reveal that this particular engineering sample is made on the B0 revision of silicon and uses Intel's next-generation LGA 1851 socket. Multiplier specs show that the maximum boost clock is somewhere in the 5GHz range, similar to Intel's outgoing 13th and 14th Gen processors.

The model in question could be any of the three K SKU parts we know of right now. Previous leaks have unveiled three unlocked K-series variants for Arrow Lake-S: the flagship Core Ultra 9 285K, Core Ultra 7 265K, and Core Ultra 5 245 K. The Core Ultra 9 285K will purportedly have 8 Lion Cove P-cores and 16 Skymont E-cores, Core Ultra 7 285K will have 8 P-cores and 12 E-cores, and Core Ultra 5 245K will come with 6 P-cores and 8 E-cores.

One of the most interesting tidbits from the CPU-Z screenshot is the lack of hardware-accelerated AVX-512, as noted in the CPU-Z instructions entries. This little detail suggests that Intel is once again derailing AVX-512 for another generation, leaving AMD's competing Ryzen 9000 series processors as the sole models to support the full-fat AVX-512 acceleration units.

This is not the first time Intel has removed AVX-512 functionality from its hybrid CPUs. Intel began pulling AVX-512 support, starting with Alder Lake , due to complications that stemmed from Intel's decision to include AVX-512 support in its Golden Cove P-cores but remove it entirely from its Gracemount E-cores to save space.

The lack of AVX-512 support on the Gracemount cores forced Intel to completely remove AVX-512 support from Alder Lake CPUs altogether. However, the first batches of Alder Lake CPUs (and motherboard BIOS firmware) ironically allowed you to run AVX-512 instructions. The only caveat is that users had to disable the E-cores from the BIOS first for AVX-512 to work. Eventually, Intel culled this workaround entirely by first disabling AVX-512 enablement in firmware and then fusing it off physically on newer Alder Lake batches.

This trend continued to Raptor Lake/Raptor Lake Refresh, and now it appears to be making its way to Arrow Lake-S. This is pretty disappointing since AMD has enabled full 512-bit acceleration paths for AVX-512 with its Zen 5 and Zen 5c cores . The icing on the cake is that AMD can also run AVX-512 with minimal to no penalty to clock speed, which is a far cry from Intel's chips, which have had to reduce clock speeds when running AVX-512 instructions to prevent the CPUs from overheating.