I was guessing which could be the practical downsides of the patches for these risks and also if a user decides to not apply these patches.
In the middle of January I bought a refurbished HP laptop, provided with an Intel i5-3320M (Ivy Bridge), which I upgraded with 8 GB of DDR3 RAM and a Samsung SSD 850 EVO; the OS is Windows 7 Ultimate 64 BIT; since the first day I obviously installed all the recommended patches from Microsoft, and I think that there was also already available the patch against Meltdown, which is activate by a pair of registry keys:
FeatureSettingsOverride as reported here https://social.technet.microsoft.com/Forums/en-US/fd9f2f4f-2534-4d61-86cd-fa5f38ac1557/meltdown-and-spectre-must-registry-value-featuresettingsoverride-manually-set-after-patch?forum=winserver8gen
Furthermore also HP released a patch, against Spectre, which consists in a BIOS update for the microcode of the processor. For now I had only enabled the patch against Meltdown. I tried to disable the Meltdown patch, and I clearly see an improvement in the general responsiveness of the laptop, is not an exaggerated improvement, but is evidently noticeable: I could say that I could live with this patch enabled, but i fear that if I will also install the BIOS patch, I would see a more evident decay of the general performance of my laptop, also in terms of battery life. Furthermore the patch from Microsoft is easy to disable, but if I update the BIOS, HP seems to state that is not possible to revert to an old BIOS revision.
By installing/enabling both patches, in which exactly terms these will impact the performances? I heard something about general troubles here: https://newsroom.intel.com/news/root-cause-of-reboot-issue-identified-updated-guidance-for-customers-and-partners/ I mean: the slowness, which part of the hardware/software will bite? The speed of ram? Will make heavy the load on the processor? Is kernel related? Could impact the battery life?
And the last important question: what we could expect for the future? There are, still, a lots of old operating systems and no longer upgradable firmwares; will come a day where/when engineers will be able to quash these vulnerabilities?