Arm clarified that C2-Ultra’s maximum instructions-per-cycle improvement over C1-Ultra is 7% under specified parameters, excluding memory-bandwidth gains.

A September 8 editor’s note from Chips and Cheese says Arm contacted the publication to clarify the comparison between its C2-Ultra and C1-Ultra CPU cores. The corrected maximum instructions-per-cycle, or IPC, improvement is 7%, using the parameters referenced in the article’s endnotes.

The clarification explicitly says the memory-bandwidth improvement does not factor into that IPC improvement. Consequently, the source reports two distinct aspects of the design comparison rather than a single combined performance percentage.

The 7% is a maximum under specified conditions, not an average across workloads or a measured improvement for a complete server. The supplied excerpt does not reproduce the endnote parameters, benchmark results, clock frequencies, or memory-bandwidth figure, preventing a more detailed numerical comparison.