Memory problems *are* an issue with SL on the Mac.
A quick example: old-generation iBook (800 MHz or so) with 128 MB of RAM. After almost 15 minutes or so, you get the first frame generated. Expect no more than 1.0 fps on an empty sim. If you can last longer than 20 minutes without a lockdown, you've beaten my own record.
Test case #2: Old-generation eMac, also 800MHz, but with 384 MB. You get 2-3 FPS. It works rather well and is stable. Don't jump to The Edge or Neufreistadt, though (too texture-intensive!).
Newer-generation (ie. 2003) PowerBook G4, 1.25 GHz. With 256 MB, forget it; it'll crash and crash and crash all the time. If you're lucky to see anything at all, it'll be around 2-3 fps. Now update it to 512 MB. It'll run smoothly enough and go to 7-15 fps easily
if you have no other application active at all (die-hard Mac OS X fanatics will happily kill all unnecessary applications from the Terminal shell). Jump to 768 MB, and now you'll be able to have Safari open with one tab (enough for looking up the BadGeo Wiki
). Performance will stabilise around the 10 fps on most spots, and go up to 15-17 (with 64 m drawing range) on good sims. Go to 1 GB, and you'll be able to run Adium, Mail, Safari, a Terminal, and still get adequate performance on SL. Update to 2 GB... and well, the memory problems simply disappear. I've tried often to measure when SL "peaks" with memory consumption, and I've
never seen it take more than 1.5 GB.
So, yes, memory does a HUGE difference. If you're living with 512 MB, make sure you tweak your Mac as much as possible — keeping all the useless services out of the Mac (yes, Dashboard can easily eat up 400-500 MB of virtual RAM just to display a weather report on a widget that you watch perhaps once per day...). If you have 1GB+ memory, you'll be able to run all the useless bits without worrying much; and if you're lucky to have 2 GB, feel free to run all your applications at the same time and waste memory right and left
Now, Mac laptops have an additional problem: overheating. I managed to punch a hole through the on-board ATI Mobility Radeon 9600 (yes, literally — this always astonishes the techies at the Mac repair store: "What have you been doing with your Mac??" "Just using SL for 4-6 hours per day, nothing more"
. Fortunately for me, that was while it was under the warranty.
Due to (possibly) an (industrial) design failure, the memory slots, since they are on the bottom (like most laptops anyway), tend to heat up
a lot and get no dissipation — they're on a user-accessible "boxed" thingy, which apparently is not ventilated properly by the lateral/back fans (fan design depends on the model you have). After trying several approaches, the best way to dissipate some of that heat seems to place two lateral strips of cardboard or a similar material (make sure that the fans have a clear access — on the lateral-fan model, they point outwards but also slightly downwards — so your strips of cardboard should
never cover them!), one at each side (left and right —
not top and bottom, or you might cover the memories by mistake!).
This will allow the laptop to run slightly cooler. "Slightly" is the key issue here; it should be able to run internally at around 60-65ºC (140-150ºF). However, I found out that the laptops with two memory slots will have the "external" slot overheating very quickly to the point of utter instability — or even Mac OS X failing to recognise it at all! This leads to many crashes and total lockdowns, as the "outer slot" is actually being incorrectly reported as "being there" but it's too hot to be working properly. So when SL starts to eat up memory like crazy, and drawing RAM from the external slot — boom! There goes your machine!
It happened to me so often that I'm now considering having just 1 GB on the internal slot, and putting the rest of the memory I can afford on the external one. 1 GB will be more than enough for system + SL (with room to spare!) and with luck, even when the laptop overheats, it won't ever use the dreaded external slot at all.
This became more serious with the latest releases of SL, ie. the ones where they included the in-world browser (SL increased its size considerably due to the support of all the new libraries...). So, Eric, I wonder if you didn't have a PowerBook or iBook, and that all you troubles came from this curious mix of circumstances: SL needing now
slightly more memory than before, and the external memory slot overheating and not getting recognised properly by Mac OS X.
Follow Shirley's advice. Get at the very least 1 GB of RAM, and if you have a laptop Mac, put the RAM only on one of the slots... namely, the internal one.
