OS X Bottlenecks and Caching

Although the performance of OS X on the dual 2GHz G5 system that I'd been running was definitely acceptable, there is definitely room for improvement. The overall responsiveness of the system was decent, but go back to using a top-of-the-line PC in Windows for a few minutes, and you definitely feel a bit sluggish on the G5. I would say honestly that a 3GHz G5 would be a good speed to have; although, I have yet to try out the new 2.5GHz G5s to see how much things have improved with a 25% increase in clock speed.

I've already mentioned video memory as being a bottleneck under OS X, thanks to the OpenGL accelerated UI. But luckily, with a more expensive video card (note: it's a shame that even a $3000 G5 comes with a measly ATI Radeon 9600 - shame on you Apple), that problem can be resolved; although, only through the expenditure of more money. There are, however, other performance related issues to which I have not been able to find solutions, even through faster hardware, which is definitely disappointing. The biggest issue seems to be scroll speed under OS X. Scrolling through any sort of window is much faster under Windows than it is under OS X. Take a browser window for example. If there's any flash running on the page and you try to scroll, you'll be greeted with a decently fast, but stuttering, scroll. It's almost as if saran wrap is behind each and every Finder window just to make things interesting. Regardless of what causes it, it's annoying - but thanks to how nice and polished the rest of OS X is, it's something that can be ignored. It does get frustrating at times, but it's one of those things that I'm able to live with, surprisingly. I think that I'm beginning to understand much of Apple's user base.

Performance isn't always a negative thing under OS X. In fact, there is one aspect of OS X's performance that I do believe significantly outshines that of even Windows XP: caching. The biggest pet peeve of mine as a PC user is hearing that hard drive crunch and having it be the reason for an interruption in my work, play or whatever else that I may be using my PC for at the time. I always get the upgrade-bug just as soon as I hear that drive crunch away, and immediately, I want to upgrade any and everything in my system to make those few seconds that feel like an eternity cease once and for all. Of course, regardless of how much I throw at the problem, it's always there and although I can lessen it, I cannot rid myself of it.

What I found in my time with the G5 and OS X was that it does a marvelous job of caching, to the point where after the first time I start the machine, I rarely hear the hard drive being accessed. Furthermore, I definitely don't feel as slowed down by it as I do under Windows. Again, I feel a bit lost writing this without a complete understanding of how Apple architected the caching system of OS X, but the results are positive and noticeable.

The obvious requirement for any OS that caches heavily is a lot of memory; while my system shipped with 512MB of memory, I quickly found the need to upgrade to more. At first, it was 2GB, then 4GB and I even contemplated going up to the 8GB limit; although, with 4GB, I definitely have memory to spare. What I found, however, was that unlike under Windows, the extra memory actually did something under OS X. The more room it had to cache, the more it spread its wings and the better it did. Obviously, there are limitations. For me, beyond 2GB wasn't really necessary (I was mostly testing out a set of 1GB modules that OCZ had sent) and even up to 2GB, I could've probably been fine with somewhere between 1 - 1.5GB without a change in the feel of the system. With enough memory, the I/O bottleneck that I had been used to dealing with for so long isn't gone, but significantly lessened on the Mac. This doesn't apply if you're doing anything I/O intensive, such as running a file server, database (to an extent) or video editing, but for a user like me, the difference is significant - and appreciated. In fact, I'd say that this is one of the things that kept me happy with the system for so long.

What you want is what you get Stability
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  • brichpmr - Friday, October 8, 2004 - link

    #53, I can't prove or disprove your statements; but the bottom line for me as a dual platform user, is that OSX is a very cool computing environment that gets better with every point release; it's very stable, malware free (so far) and lets a bunch of us earn a handsome income, even in a Windows-dominated enterprise....as a workhorse machine, the numbers become secondary to a user's productivity...the Mac is very productivity-friendly. I won't even mention how much fun it is to run F1 Championship Season in 1280 by 1024 with a nice Logitech force-feed wheel...whoever thinks the Mac can't play good games needs to re-think!
  • gherald - Friday, October 8, 2004 - link

    To #48 who says: "If a lot of PC users would open their minds and try using a Mac for 30 days: they would appreciate what us mac users like about the platform."

    My answer is: The usefulness of this article is that we don't HAVE to spend time and money doing that. We get to read about someone else doing it -- someone who's opinion we trust.

    This is the most fair minded Mac review I have ever seen. Kudos to Anand for giving us insights on a platform that is too expensive for most of us to afford to try out on our own.

    The $3000 price tag is interesting. I recently built 2 AMD64 machines for somewhat less money: A 3400 for windows, and a 3200 for Linux. There is no doubt in my mind that this was the best value, especially since I play a number of windows-only games but prefer Linux for everything else. I don't think the Mac even comes close to beating the power, compatibility, and flexibility of such an approach, at least for my purposes.
  • skiboysteve - Friday, October 8, 2004 - link

    cindy are you kidding me?

    ALl it takes is one air cooled 2.4ghz Athlon64 to match a DUAL WATER COOLED 2.5ghz G5.

    Not to mention a single air cooled 2.4 A64 is cheaper.

    And that barefeats article is so laughable, one of the shadiest configurations of hardware i've ever seen... not trustable at all.

    I dont have the info in front of me, but there was a G5 bench mark from an actual hardware website worth something and the G5 got smoked on single proc. and only matched with dual.

    And where the hell did you pull the PPC970 does more ops per clcok than an Athlon64 info? It has a 16 stage integer pipe, gee, hmm, thats 25% more than an athlon64. Now I know your going to say it can have 200 operations in flight, but... "So while the 970 may be theoretically able to accommodate a whopping 200 instructions in varying stages of fetch, decode, execution and completion, the reality is probably that under most circumstances a decent number of its valuable execution slots will be empty on any given cycle due to dispatch, scheduling, and completion limitations."
    (http://arstechnica.com/cpu/02q2/ppc970/ppc970-5.ht...

    The problem with the PPC970 is its long pipe wide execution scheme would be good but it doesnt have enough resources to fill the wide ass pipe and all the execution units, which is exactly as expected becasue its a cut power4 chip. "The 970's integer hardware was designed to deliver 64-bit integer performance, and it was also designed with the ridiculously large caches of the Power4 in mind. When it you decrease the cache sizes to desktop computing levels and run 32-bit code on it, it starts to look less impressive next to the P4."

    Your "facts" are terribly flawed and I just had to post about this because somehow no one else did.

    The PPC970 is the best chip the Mac has ever had, but its clock is not high enough, its too hot, and its operations per clock are no where near the G4, and behind the A64.

    (http://arstechnica.com/cpu/03q1/ppc970/ppc970-1.ht...


    I realize this probably comes off as a massive PC-bias attack on you, but honestly, get your facts straight before you start praising the great PPC970 chip on a HARDWARE website, where people KNOW whats up.
  • Sakamura - Friday, October 8, 2004 - link

    1st post. Mac user. Reader of AnandTech for a long time for PC needs and other cross-platform niceness.

    For the few answers I can provide that aren't already addressed in the 5x messages prior to mine:

    - Applications are "packages" like explained. Some do use the Library to install ... And some ask for a admin password to add their kext in the system library. It all depends on the app.
    - Caching is indeed very optimized. Still no Ext4 but very optimized. Thanks to BSD base.
    - Search engine is not cached. It's a system service that allows you to sort and classify any sort of data. That's the same sorting algorithm that determines if a mail is spam or not. This is also used in file search, text search, dictionary and whatnot.
    - User interface is not meant to be snappy. Strangely enough, I have almost the same user interface speed on my G3/400 than on a G5. But then, the actual work does slow down to a crawl when doing processor intensive tasks. Alas, today, this means Mail, Safari, Quicktime. But nonetheless other than the actual "work" being done on something, the interface remains decently fast all the time.

    Great article, nice points.
    Have a nice day
    Mike
  • CU - Friday, October 8, 2004 - link

    You can run X11 and all the open source stuff on Windows to. You just install cygwin. Don't some dist. offer running linux inside windows also.
  • jecastej - Friday, October 8, 2004 - link

    44 - "price to performance" is perfect if you need to justify a purchase to your office or IT department. Which maybe is the 98% of the cases.

    It may look like luxury but sometimes is necessary to value other human needs. Business creative environments benefit from aesthetics. Apple's software/hardware provides an alternative at a reasonable price to performance ratio. Won't kill to have this option.
  • punko - Friday, October 8, 2004 - link

    Wow.

    And I thought Coke vs. Pepsi was bad.

    All I can say is that as a computer user from way back (punch cards and PDP-11's anyone?) I have never owned or used a Mac (other than to print false birth certificates in high school to go to bars) but I have occasionally wondered what it would be like to have one.

    Anand has a better understanding of the total breadth of the PC environment, and so is a perfect lens with which to view the Mac world from a PC user perspective.

    All the bile and venom swishing around here in the comment trenches isn't worth worrying about.

    Great article Anand. I know more is coming down the pipeline concerning the Macs; and even though I am dreaming of a AMD64 upgrade, I will read and consider the informed opinion of a knowledgable computer user.

    Cheers.

  • rvirmani - Friday, October 8, 2004 - link

    About as objective an article as you can expect from a hard core PC user (who makes most of his income from the PC World).

    I switched to the Mac 2 years ago, and went through the adjustment.

    I think the key thing I want to point out is:
    1) less irritation on a day to day basis
    2) My system has never crashed ( although I do fix the "permissions" on a weekly basis using the built in disk utility

    3) The other benefits of the mac are the iapps (Which Anand did not get around to looking at)

    4) I use a Power Mac G4 with 2 Gig of Ram and it is plenty fast for day to day things like MS Office and Web research.

    I think the "performance" mentality of many PC enthusiasts is really the biggest barrier (I like not worrying or thinking about the hardware too much).

    5) OSX is much better at multi-tasking - even on a single processor machine.

    If a lot of PC users would open their minds and try using a Mac for 30 days: they would appreciate what us mac users like about the platform.

    A good start for Anand, and I look forward to more explorations of the Mac platform.

  • sprockkets - Friday, October 8, 2004 - link

    err... that was 256MB of memory with 233MB used due to a shared SiS740 chipset in my Shuttle system and 165MB in swap, was running transcode and a few other smiple apps, such as Konqueror.
  • sprockkets - Friday, October 8, 2004 - link

    I find that browsing is fastest with Opera on any platform, yet it was almost as fast with IE and Firefox on a new install of Windows XP home. I only put 256MB of RAM in it yet it boots and runs applications quite nicely. I notice the delays in web pages when using FireFox in Linux, though I could care less (has 256MB too with.

    The bottom line is, you shouldn't have to use 1GB to 2 or even 4 GB of ram just to get a nice response time. That and dual 2.0GHZ is still available. That and browsing and multitasking shouldn't require DUAL 3.0GHZ PPC processors.

    Another point, if Mac OSX was made for an X86 processor, I would buy it. But since it isn't, and SuSE 9.1 is free anyhow, with just as customizeable KDE or GNOME desktops, not to mention light and fast IceWM desktop, why bother.

    Off topic, but doesn't Windows NT5 varients shut down after 45 days of uptime?

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