What I'm saying is if the desktop itself is blurry because it's not having LumaSharpen applied to it, and I'm using an image viewer that is working on the desktop, and does not have LumaSharpen applied to it, then that screenshot will have the blur of the desktop applied to it, therefore making the image that while it does yes, look almost the same as the game in fullscreen, may in fact be slightly out of focus. I'd have to try comparing with a program that I'm able to switch into fullscreen and back out of almost instantly to compare it with the image of the screenshot also set to fullscreen, by pressing alt+tab. If there is a noticeable blur applied to the screenshot due to it displaying on the desktop, then I guess I'd know whether the desktop needs to be sharpened. That's of course unless for whatever reason the image viewer applies sharpening, making the image appear the same as the game did in fullscreen, but the rest of the desktop outside of the image viewer does not have that sharpening. It really depends on how the image viewer program actually functions, and I don't have the answer to that.
Yeah you have to have both browsers to compare but for me Chrome browsers definitely don't have the stutter present in Nightly/Firefox, it can be kind of subtle but it's definitely there, it becomes far more obvious to me when I'm not using the HTML5 player. Overall Chrome is known to perform better with video processing for many years from what I understand, it's why many of those similarly complaining about Chrome's removal of the option to disable DirectWrite, was followed by comments of reluctance towards switching back over to Firefox, which used to be the best browser for performance, but that ended years ago. I hoped the multi-thread support being introduced in Firefox browsers would help but it doesn't seem like it was enough in my computer's case. All I know is a lot of people including streamers seemed to be very happy that they were adding HTML5 support, because it was so much less of a strain on hardware than the Flash player. When I compared Firefox vs Chrome there's a notable difference though it may not be that noticeable depending on the type of action going on and what game is being played. Some streams can go from almost choppy at times for split seconds to constantly smooth when I switch browsers. In general whereas Firefox/Nightly felt like it wasn't totally smooth, Chrome does feel that way.
I think I heard recently that the 6th generation i5 or maybe it was i7 CPUs were something like 50% faster compared to my 1st generation i5 CPU Hz for Hz. So a 1GHz CPU today would be equivalent to a 1.5GHz CPU back then, something along those lines.
To be honest I don't have a new CPU to compare with so I've no idea what the difference would be, the most I've been able to gather is that on new CPUs if you were already getting adequate FPS at the high end, the more notable improvement might be that your minimum FPS would be considerably higher, and that you are less likely to get a sudden drop into the single digits at resolutions greater than 1080p.
And yeah I know a lot of the tips out there on the various guides, or individual suggestions I've checked out in the last decade probably don't do much if anything, but I wasn't referring to those generally lame and ineffective suggestions that are generally the first go to ideas for many people. I don't keep a long list of everything I'd done to this computer, it's been more of a natural development of discovering and rediscovering what I consider valid and useful tweaks, but my experience is that it's helped considerably, even if others might claim placebo. I've seen plenty of cases where the "experts" and the majority of people holding an opinion have been wrong on all sides of a variety of issues during my life, looking at both modern and historical instances, and I myself have been wrong many times and done what I can to correct myself and improve upon my execution for the next time, when I've been aware enough to catch myself in the act.
As far as running my computer at basically idle like you described, yeah it's no problem for this CPU either. According to the people helping me on my long topic over at Tomshardware my CPU should do fine as long as it's overclocked if I choose to match it with the RX 480 (and this has been confirmed by a video showing benchmark comparisons on the same CPU), and my HX650 PSU is more than able to cover the power demands required to run it at full throttle. Until I've the money to afford a new CPU + Motherboard and possibly a new set of RAM, and whatever else might be needed, I'll be sticking with this one. I was hoping this monitor would be exactly what I was looking for, and it almost is, LumaSharpen definitely helps things, I'd have been perfectly happy for at least a few more years without upgrading anything besides maybe the graphics card, but I'm not sure now when I might change the monitor out.