Grandparent also said
> Sure you might be able to do some of those things at a very low resolution on a Mhz system, but not in any meaningful way.
> You must be really young.
Maybe they are, maybe they aren't, but that's an unfounded assumption. There are plenty of middle-aged people who haven't got a solid idea of the limits of pre-Ghz-scale hardware for use cases that weren't all that mainstream back then, and I'm sure there will also be young people who've tinkered with some old Windows 98 box and could give us a pretty solid opinion.
At any rate, I've used a succession of Mhz-scale systems (starting with a 386 that struggled valiantly to run a copy of Windows 3.1 that someone had installed on it) and I'm definitely not very young.
> >* Graphics design
> We did
With rough and simple tools, limited to low-res designs, very limited brushes, super crude brush simulations (if any). Procreate on the iPad blows all of it out of the water effortlessly with its worst brushes using a finger for a stylus, and that realtime brush simulation has been taxing for earlier iPads, that have always been orders of magnitude above Mhz systems. I used Photoshop CS and CS2 a lot back in the day; they were resource hogs and still very crude compared to current entry-level apps. We've really gained a huge lot in that department.
> >* Video editing
> Ditto
At what, 640x480, 15fps? I remember having annoying render times for things that wouldn't hardly even count as filters nowadays at such resolutions, maybe 800x600, but I'm sure that ball-shaped logitech webcam could do no more than that. Snapchat replaces whole faces in realtime with eerie accuracy on what must be much higher res.
Color grading Full HD, 30fps? As if. I guess you couldn't even play that without stutters unless with dedicated silicon to begin with.
> >* Animation
> Ditto
Low-res, crude, and anything halfway detailed and interactive: Low-fps. Manipulating anatomy models like those at https://www.zygotebody.com/ in realtime? I doubt my Core 2 Duo laptop would have been up to that. I had similar software for Windows 98, and it was absolutely primitive and still taxing the CPU and GPU.
> >* 3D CAD
> Older than you think
With less precision, much, much lower model complexity, and much cruder tooling. A large number of components, complex shapes, joints, ... that's going to hit hard limits very quickly. I'm hitting hard limits with that sort of thing nowadays, but I'm hitting them somewhat later than even a few years ago.
> >* 3D Rendering
> 3D rendering was born here, and we were playing 3D games perfectly in 1996-2002
I don't play a lot, but between Gothic 1 and Witcher 3, graphics have improved by an incredible amount, it's day and night, and I can't even go to full details in Witcher due to my aging GPU. Technically, those systems could do it, sure – but only with super short visibility, very crude models and extremely limited shaders and animations, crude collision detection, ... Gothic required at least a 700mhz Pentium 3, so it's pretty representative I think. Of course, those limitations work better for some games than for others, but they still were brutal limitations.
> >* Multitasking
> Linux, KDE3.
Also quite limited, though. Just what fits on a single Mhz-scale core. On my Windows 98 PC, I had to close CPU-intensive applications all the time because things would start to stutter; I believe Windows 95 would sometimes just bluescreen under such conditions. Things got a lot better on Windows 2000, but I think that may have been on my 1Ghz Athlon already. Those early Linux desktops were pretty unstable with lots of multitasking as well, I faintly remember lots of freezing. Things did slow down perceptibly at any rate when doing multiple resource-intensive things. Technically possible, sure – but it absolutely helps to have lots of fast cores.
Of course, a lot of the legwork to make those use cases perform is nowadays done by GPUs or huge amounts of RAM, and profit lots from multiple cores, but I'd say a Mhz-scale system should have a period video card, too, and MB-scale RAM, and be single-core, otherwise it's kinda pointless. And under those conditions, all of above things were technically possible, but really severely limited – still are, in some cases (CAD...), but wayyy less than back then.
Does that qualify as "not in any meaningful way"? I guess it depends. It was meaningful for me back then, and it made possible things that hadn't been possible before, and of course we were always content with what we had, not like thouse young'uns nowadays, and walked uphill to school, in the snow, both ways, every day – but looking back, the capabilities of my Mhz computers feel incredibly crude and primitive by today's standards, and even a lower-end gaming PC has little problem running Autodesk Fusion 360 (for which there's even a free hobbyist license) with models of surprising complexity, and I'm sure that enables many many more things that wouldn't have been feasible on Mhz hardware.