Earlier today I was exploring my old, secondary PC. It's 5 years old, and I use it less than ten times a year. But I've played TS3 on it a lot in the past.
Then, I found this video.

It's from about 3 years ago, and it was recorded with the in-game capture tool. I probably recorded it to show off how good my game performance was at the time, because the PC is by no means underpowered.

So what the hell, how did I do that? I'm lost on how I got the game to run so smoothly, but obviously it must've happened. It being a new save helped, and not having all expansion packs installed at the time (IIRC) must've helped, too. But not even the base game is normally that nice.

So really, if you've never seen TS3 without lag, there you go. I'm posting this because I thought it was cool, and I'm posting it because I'm definitely going to try to replicate it in some way, preferably in proper HD and 60fps.

Now for comparison, the best performance I get today.

Few small differences, though. This save is 3 years (12 Sim weeks) old, I'm playing in 1440p instead of 1080p, and I'm using a resource-heavy postprocessing overlay which reduces the framerate by up to 50%.

I remember a while back I was doing tests and loaded a new Sunset Valley with no mods or CC, and being shocked at how smooth it was. Is was basically the same as your video, or maybe nearly as good.
I just did your aerial test on a heavily modded (since 2009) Al Simhara, and it stutters a lot more than yours. But I can't live without the mods that are probably making this happen lol.

It's not really the low framerate that ruins the game, it's the freezes and stutters. Now I've gotten used to 25, 20, sometimes even 15fps. 15fps is in fact more or less the average on my Sims' home lot - it goes all the way down to 11-12 - but the freezes are what really annoy.
A 1-second freeze is annoying. So is a 2-second freeze. But sometimes they're as much as 5 seconds.
And that's just not cool, that's really shit. Especially since, when it gets going again, I'm still stuck with the poor framerate. But I bring the framerate upon myself, through my heavy use of ReShade. Because I'd be getting 25-35fps without it.
But again, and I'll keep saying it, it could be worse. I may have to save every 5 minutes, but I can use whatever amount of mods and CC I want, I can ReShade the absolute shit out of my game, I can clutter my lots to hell and back, and my loading time will still only be 5 minutes. And crashes are all but extinct. I nearly had one yesterday, for the first time in months.

Except ErrorTrap and Overwatch, of course, which make sure that good game performance is possible for more than two minutes.

And sorry about your laptop. I lost a PC to TS3 once, so I went without for 2-3 months.

Hope you guys don't mind a question from a player (me) who doesn't care how crappy his game looks, within reason, as long as the story progresses the way he thinks it should. How exactly does a game program nearly crash? In my experience, usually a program has either crashed or it hasn't. Sure there can be temporary lag conditions if something correctable is going wrong, but it's not like the program gets swiped on the side by another vehicle, wobbles for a bit, then keeps going or at least not as far as this player can usually tell. Is there an early warning sign of impending doom that you aren't sharing with us? Does Windows say something like "TS3 was going to stop working and would have produced a crash log but changed its mind at the last minute, just thought you would like to know"?

And yes, Nitromon sorry to hear about your laptop and subsequent ban.

That's how my game used to run, back then I only had WA, AMB and LN and was only patched to what was on the disks, no CC and no mods, Bridgeport acted up from time to time but the rest ran smooth.

Once I started patching the game went to hell, IMHO Pets didn't just break a lot of CC it broke the game.

A near crash is when the game's memory consumption exceeds 3100 megabytes, but doesn't crash. Anything above 3200 megabytes is an imminent crash.
But, I've had my old secondary PC run the game at 3800-3900 megabytes for several minutes without crashing once. So for all I know, this PC will soldier on, because my strategy for making TS3 run well is throwing brute force against it until it stops being a piece of shit.

A Mac and a laptop? Ouch, dude. You need to get that sorted out. You need to get yourself something with two digits of RAM and four digits of graphics card.
And for the record - it only took me 2-3 months because I was too much into console gaming at the time to really give a shit.

I imagine everything's just a little darker in the Simverse. It's not like the sun suddenly turns off, because that'd kill them all, but it goes into power saving mode.

You could remap those keyboard buttons. Or, this will cost a little more and probably be a bit painful, but you could remap your thumb with your pinky.

As for weird and wacky, this reminds me of when someone I knew complained that an entire time zone in India is on the half-hour and they are impossible to work with, why can't they be on the full hour like everyone else? I had to point out to them that to the billion or so people who live there, it's the rest of us in the world that are on the half hour. Deal with it.

Although, to be fair, that doesn't sound like one of the higher end Macbook Pros at all.

I absolutely need your PC. I'm running a crap one, i have a GTX 1050 Ti but an AMD Sempron(!) with only 1.6Ghz. Of course, i can barely play the game so i have to play it at my dad's house, he has an AMD A10 and it still lags like hell(Not as much as in my computer though).
I'm seriously thinking about getting an AMD Ryzen. The stuttering in this game is driving me nuts!
The pop-in in this game is atrocious though, even on high-end PC's.

Well, that's kinda (sometimes) how my game runs (and I have obscene amounts of CC and mods). Unparking my CPU, using a RAM disk and buying an SSD definitely helped, but it was completely getting rid of all my CC and mods a year and half ago and starting anew what made a noticeable difference. Now I do a thorough testing of all mods and CC on a secondary My Documents/Electronic Arts/TS3 folder before moving the contents to my main game folder. I also noticed that playing on certain custom worlds (for example the ones made by MySimRealty) actually improves performance over EA worlds. I only use EA worlds as travel destinations nowadays. The only EA world that actually runs really well is Sunset Valley, but it doesn't have a lot of space to place EP community lots and venues. All in all, smooth gameplay is possible in TS3 (though not everywhere and at all times) but some people expect smooth gameplay on laptops/low-end PCs or unoptimized games (I consider an unoptimized game to be any game without Overwatch and ErrorTrap at the very least), and those are unrealistic expectations.

My game runs totally fine with everything except K Perry installed. I am on a 5 year old i7 desktop.

If only EAxis knew how to properly optimize a game. We shouldn't struggle to run a 2009 casual game with 2017 gaming rigs.
I use NRaas' Porter to put my family and their friends in the library and move them to a new game when i notice it gets too laggy. And the fixed worlds and NRaas mods also help a lot.

Would like to point out that that first video was shot on a PC less powerful than my current one, in slow motion, and then sped up again.
My actual performance, on my current PC, is closer to this, and as you can see it's rife with stuttering even when practically nothing is happening.

For the record, my current PC has a GTX 1070, an i5-6600K and 16 gigs of RAM.

I just played for about 6 hours(!) and noticed 2 times there was a second hesitation before my sim did something. So I am not complaining. My game does not seem to be rendering distant lots as well as I think it should at the moment, but gameplay is smooth/fine.

My specs:
Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.140303-2144)
Language: English (Regional Setting: English)
System Manufacturer: Hewlett-Packard
System Model: h8-1020
BIOS: Ver: CAR_7 3.bin vCAR7.03
Processor: Intel(R) Core(TM) i7-2600S CPU @ 2.80GHz (8 CPUs), ~2.8GHz
Memory: 8192MB RAM
Available OS Memory: 8174MB RAM

I have no idea what most of that means, but it is working.

It really doesn't sound like they'll need it. I mean, going for 6 hours without so much as a 10-second freeze is nothing short of amazing.

I have the program for parking/un but don't seem to need it. And I am not sure if the few pauses I saw only as I looked for them were actual pauses or just changing from one animation to another? Once she was sitting down and once just starting eating. So they probably were not even lag? I want to check the distant lot rendering though. I may have it set too high. I need to play with that a bit.

I have had very good experience with HP thank goodness. P4 before this way back and this and 2 HP printers. All have been fine. So far, so good.

My graphics card is darn bad by today's standards I am sure, and the driver is ancient. But an update removed the catalyst control center and so I went back to the old one. So far, all works, and my motto is if not broken, leave stuff alone.

Even if you think you don't need unparking your cores (because your game doesn't lag), you actually DO. Why? Because unparking your CPU cores ALWAYS, and I mean always, improves AI. I believe the latency of parking/unparking cores affects AI immensely. AI, autonomy and idle behaviors seem to have one of the lowest priorities when it comes to CPU processing, so any latency will result in idle Sims / Sims looking at the horizon and don't doing anything, emptier community lots, less idles behaviors (animations that play when a Sim is idle depending on their traits), etc. If your playing on a desktop, there's no reason to have your CPUs parked. It was implemented to save power, but that's unnecessary for desktop PCs in most cases. For me, it was like day and night when I unparked my cores. Suddenly, community lots were packed with Sims (up to 30 Sims some times), Sims were also more lively, very seldom standing still looking blankly, and doing more social interactions and more idles and autonomous actions related to their traits. It was like a breathing life into my game.

I got Park Control to hopefully fill community lots. I will go ahead and try it. Thanks!