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Linux 4.20 is Running Slower Than 4.19 On Intel CPUs (phoronix.com)
Freshly Exhumed writes: An intentional kernel change in Linux kernel 4.20 for enhanced Spectre mitigation is unfortunately causing Intel Linux performance to be much slower than with 4.19. That change is 'STIBP' (Single Thread Indirect Branch Predictors), which allows for preventing cross-hyperthread control of decisions that are made by indirect branch predictors. It affects Intel systems that have up-to-date microcode and CPU Hyper Threading enabled. Phoronix gives the evidence.
AMD for the WIN!! will apple move mac pro over?
You can easily disable this patch with a boot command-line argument. Unless you are running a heavily VM-ed data center with shit for security, why would you cripple your system over the most esoteric hacks known to man and that - Oh! By the way! - require that you are running malware on your system already? (And spare me the horseshit about JS - that can ONLY happen in a carefully crafted environment.)
So technically not ALL Intel cpus.. I finally dodged one of the many bullets, I should buy a lottery ticket.
It's only worthwhile in some situations.
I manage around 15,000 hypervisors which have VMs that don't ever run untrusted or arbitrary code, they aren't internet connected, etc. A 10% performance hit means millions of dollars of additional compute and network infrastructure.
And don't tell me to use AMD either, the price vs. Performance ends up being more costly at the scale and density we require.... and that's pretending we could swap existing servers out for no cost.
Ryzenfall and related vulnerabilities still haven't been fixed
Ryzenfall is a PR exploit not a serious vulnerability, it requires physical access.
Investigators uncovered an article by Viceroy Research condemning AMD on the exploit and noted how the article was published less than half an hour after the exploits were revealed. Given the polish of the article which appears to be written many days in advance, and wording of the article which suggests that it is financially motivated, many were quick to accuse the exploit as a smear campaign engineered by Viceroy to short-sell AMD's stocks.
Meanwhile, Intel still has major issues with Meltdown, which is much more serious than Spectre because Meltdown breaks the veil between user and kernel, while Spectre is a process/process leak, much easier to address at the OS level. With fresh new Meltdown exploits demonstrated, Intel is still very much in the hot seat and AMD is the more secure processor.
When all you have is a hammer, every problem starts to look like a thumb.