Apple IIgs all over again, in some ways
Prof.Wizard said:
Limited hardware acceleration of graphics (I don't think it's absolutely zero -- IIRC it's supported to some extent on some cards). I've heard that the reason this is supported so badly right now is that they want to make the graphics acceleration super-stable so nobody's "lickable" user interfaces show any glitches.
Speaking of "lickable" UIs, that Aqua UI adds lots of overhead too.
Mac OS X also uses far more memory than, say, XP. With XP and 256MB of RAM I've never seen more than a few hundred MB (probably far less) of swap in use. With Mac OS X and 512MB of RAM I've sometimes seen a few
gigabytes of swap in use. (That was with Mac OS 10.0.x; 10.1.x is a lot better but still quite bad.)
I've also heard rumors of ancient "serialization" code in the kernel that people are reluctant to touch; rumor has it that this is causing the kernel to become a performance bottleneck.
More succinctly, in some ways Mac OS X was released before its time. For my needs it's clearly better than Mac OS 9, even at this stage, but it still needs some more time to mature.
As I write this, I'm getting a really weird "deja vu" feeling...
Once upon a time Apple had a ridiculously slow operating system called ProDOS 16. (This was the 16-bit version of an 8-bit operating system called ProDOS which was, in comparison, far faster.) One reason ProDOS 16 was slow was that it brought eye candy (640x200 res. 4 color (dithered to 16 color) or 320x200 res. 256 color GUI, even including some primitive shadow effects on buttons and menus) to a machine with a 2.8MHz CPU that, for the sake of backward compatibility, would slow down to 1MHz when accessing certain memory areas and hardware devices. (OTOH, it had an onboard Ensoniq [swallowed up by Creative Labs a few years back] sound card that was unbelievable for the time (1986 or '87). If I remember correctly, the sound on Macs was inferior until 1993 or so.)
Anyway, the IIgs was blazing fast compared to its 1MHz-all-the-time predecessors when it was running 8-bit code. The 16-bit operating system was held back by eye candy however.
For many years there were rumors of a "ProDOS 16 2.0" that would be much better. What actually came out was GS/OS 1.0 (known more commonly as Apple IIgs System Software 4.0). (The machine and the OS were actually named after the eye [and ear] candy, if you think about it: GS stood for "Graphics and Sound".) The main differences between it and ProDOS 16 were (a) it had much faster disk I/O (b) it required newer firmware on your SCSI card, which meant a trip to your Apple II dealer because Apple II SCSI cards didn't have flashable firmware, and (c) it introduced a lot of incompatibilities.
Next came GS/OS 2.0 (System Software 5.0). It brought massive speed improvements. Massive meaning 800-1600% performance increases for some things (like window scrolling and menu bar stuff). Upgrading to GS/OS 2.0 alone sometimes brought bigger speed increases than a CPU upgrade (which brought you from 2.8MHz to 7MHz).
Around 1992 or '93, GS/OS 3.0 (System Software 6.0) brought some more improvments, including support for the HFS filesystem (Apple now calls it the "Mac OS Standard" filesystem). This meant filenames could now be 31 characters max. instead of 15, and partitions on SCSI hard drives could now be 2GB, as opposed to the previous limit of 32MB. There were some other small but cool features that the Mac didn't get until later on, although I forget what they were. (Oh, wait, I just remembered one: The "sound themes" feature that was added in Mac OS 8 was introduced on the Apple IIgs in GS/OS 3.0 -- that's a gap of several years.)
Anyway, I guess my point is, Apple introduced a slow eye-candy OS in the past and managed to speed it up considerably. Let's see if they pull it off again. Oh, wait, I forgot one other point: the memory consumption went up over time (you could get by with 512KB of RAM for ProDOS 16, you needed at least 768KB for GS/OS 1.0 if I remember correctly, and by GS/OS 3.0 1.25MB of RAM was an unbearably small amount of RAM. I remember upgrading to 4.25MB of RAM (0.25MB on motherboard, 4MB on proprietary-interface memory card that had SIMM slots on it) for $600 or so. More would have been better except I would have needed to disable DMA on my SCSI card and that would cut the SCSI STR from 1024KB/sec to 512KB/sec.)
I suppose we're at the "faster I/O, but my SCSI card needs new firmware, there are tons of incompatibilities, and I need more RAM" phase at this point.
If history repeats itself more closely than I'd expect or like, a few years from now Apple will be shipping Macs with 1GB of RAM onboard, expandable to 4GB, and the only reason 1GB will be enough is because there will be a few hundred MB of Mac OS X code included in onboard non-volatile solid state storage and executed in place. (Later Apple IIgs's shipped with 1.25MB of RAM onboard, instead of 0.25MB, and the ROM (analogous to a PC's BIOS) was (IIRC) doubled from 128KB to 256KB so that parts of GS/OS could be stuffed in there.) On the other hand, Mac OS X will be blazingly fast even on older hardware at that point,
if your older Mac can take 1.5GB of RAM (some can, at least in theory) and you max it out. :mrgrn:
