This warning advisory is relevant for users of systems with the Intel processors code-named "Skylake" and "Kaby Lake". These are: the 6th and 7th generation Intel Core processors (desktop, embedded, mobile and HEDT), their related server processors (such as Xeon v5 and Xeon v6), as well as select Intel Pentium processor models.
TL;DR: unfixed Skylake and Kaby Lake processors could, in some situations, dangerously misbehave when hyper-threading is enabled. Disable hyper-threading immediately in BIOS/UEFI to work around the problem. Read this advisory for instructions about an Intel-provided fix.
SO, WHAT IS THIS ALL ABOUT? ---------------------------
This advisory is about a processor/microcode defect recently identified on Intel Skylake and Intel Kaby Lake processors with hyper-threading enabled. This defect can, when triggered, cause unpredictable system behavior: it could cause spurious errors, such as application and system misbehavior, data corruption, and data loss.
It was brought to the attention of the Debian project that this defect is known to directly affect some Debian stable users (refer to the end of this advisory for details), thus this advisory.
Please note that the defect can potentially affect any operating system (it is not restricted to Debian, and it is not restricted to Linux-based systems). It can be either avoided (by disabling hyper-threading), or fixed (by updating the processor microcode).
Due to the difficult detection of potentially affected software, and the unpredictable nature of the defect, all users of the affected Intel processors are strongly urged to take action as recommended by this advisory. （一部抜粋、翻訳しました。続きはソースで）
もう1つはメモリ周りだ。今回，メモリモジュールとしてはやはり4Gamerで独自に入手したG.Skill International Enterprise製で容量8GBのPC4-25600モジュール4枚セット「F4-3200C15Q-32GTZSW」を用いているのだが，入手したi9-7900Xでは「4chアクセスだが24GB」という，不思議な認識の仕方をしていた。Ryzen R7 1800Xでは4枚で合計32GBを認識しているので，i7-7900X環境で，CPUかマザーボードに何かある可能性は否定できない。もしかすると実際には3chアクセスになってしまっている可能性もあるだろう。