All results below are: authentic MP5,1 mid-2012 dual 3.46 GHz with 128GB RAM Sapphire Pulse RX 580 8GB BootROM 18.104.22.168.0 Mojave 10.14.5 18F132 (SMC 1.39f11) WITHOUT FULL MITIGATION (HT Enabled) Geekbench Single-Core Score: 2941 Geekbench Multi-Core Score: 22195 Geekbench OpenCL Score: 131963 Adobe Premiere Pro CC 2019 13.1.2 Build 9 H.264 Pre-Rendered Encode via Export: 4:59.23 (min) WITH FULL MITIGATION (HT Disabled) Geekbench Single-Core Score: 2914 Geekbench Multi-Core Score: 22401 Geekbench OpenCL Score: 133345 Adobe Premiere Pro CC 2019 13.1.2 Build 9 H.264 Pre-Rendered Encode via Export: 5:30.71 (min) ----- Mitigation was applied via the two Terminal commands in Step 3: https://support.apple.com/en-us/HT210108 Note for Step 1: wait at least 3 minutes holding Command (⌘)-R if you do not have boot screens (non-EFI GPU like RX580) I'm personally noticing approximately a 10% real world hit with HT disabled right now. It's not enough to slash and burn this machine, but it is enough to feel like I'm being forced to drink burnt coffee. Personally am angry with Intel for not releasing microcode updates to patch this properly, but at the same time angry with Apple for not providing a serviceable MP6,1 replacement or making information on MP7,1 available. Icing on the cake - it's still not 100% clear disabling HT actually provides full mitigation on MP5,1. Worth noting - several Geekbench scores actually increased with HT disabled. Approximately 1% for both OpenCL and Multi-Core scores. I personally do not rely on these at all, but many here swear by those numbers for everything. Geekbench 4.3.3 (401459) if it matters to anyone. Will be opening a ticket with Apple to hopefully get some clarity (or correction) on this list: https://support.apple.com/en-us/HT210107 My machine is TECHNICALLY not part of the list and would default to assume it should be supported. I'm sure this is an oversight on Apple's part, or intended to make this look like it impacts 2010-era machines only. Looks much better on paper since those are all about 10+ years old. My personal mid-2012 is not quite 7 years old right now. Despite the lack of Apple's Pro machine focus these past several years, I would still prefer to upgrade to another Mac Pro in the next 12-18 months if it's a worthy and appealing workstation.