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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  • adt6247 - Friday, October 8, 2004 - link

    #20 -- This was an article about Anand's "experience", which is hard to define. It wasn't a straight apples-to-apples comparison. He was going on his perception -- the perception of a PC user.

    Frankly, I'd love to own a Mac. I could never bring myself to buy an iMac (integrated monitor == BAD), and even the dual 1.8 is out of my price range. I'm more of a Linux kinda guy myself, but what I'd like a Mac for is professional audio/video apps, like ProTools. And OSX being BSD under the hood, I'd find it much more comfortable than Windows.
  • jecastej - Friday, October 8, 2004 - link

    What I like about this article is the safe felling / deep thinking analisis. Not anybody hating anybody else because he/she picks a different flavor.

    As a Mac user who works in computer graphics who also uses a PC at work I constantly feel that the Mac is like a taboo for the PC world, and it should not be. I don't hate PCs, I just still prefer a Mac. And as a matter of fact I'm constantly reading articles in websites like Anandtech, because what I really love is technology and freedom.

    If something else came out that I liked better and I could buy it I want to be free to choose, and to change my mind at any time.

    So this is the intention of this community: That the user takes better well informed decisions.
  • jediknight - Friday, October 8, 2004 - link

    #14: Not quite..
    1) Save memory use for 20 tabs vs. 20 windows
    2) BUT, lose functionality to compare two webpages at the same time. The fact that a modal dialog in one tab stops you from switching tabs is very annoying.
    3) Without extensions, switching between tabs uses a "dumb" behaviour.

    Not to say that I don't like Firefox, but I don't find tabbed browsing to be as big a deal as some make it out to be.
  • GL - Friday, October 8, 2004 - link

    brain29,

    I don't think Anand is being forced to upgrade. Any level-headed Mac user understands what he means regarding performance: his system is not Snappy (TM)! There are a few specific tasks, such as resizing a window, that are just sluggish under OS X. There are 2 ways to address this issue. One is by beefing up your hardware. Another is by optimizing your software.

    OS X still has a ways to go before being fully optimized. In fact, the software is quite unoptimized which is why it can drag down a dual 2.0 GHz rig. The software code itself can be tightened up, and the compiler can be greatly improved. You have to remember that Apple uses gcc which has never been known to generate optimal PowerPC binaries, and they also use Objective-C which has not had as much attention given to it for performance improvements as other languages. 10.4 will be compiled with the newest gcc which has been tuned better to the PowerPC 970 and Objective-C.

    With respect to text rendering speed, which may be at the heart of a lot of problems such as the Safari rendering speed, apparently optimizations are in the pipeline. Perhaps someone more "in the know" can elaborate or shoot down this, but I've heard that all text is rendered as bezier paths in OS X. Moreover, Quartz2D Extreme, while accelerating bezier path drawing quite nicely, did not speed up text rendering as much as it should have given that the text was just a special case of drawing bezier paths. This performance discrepancy is supposed to be addressed in 10.4.

    Apple has consistently improved the speed of OS X by noticeable amounts with each point release. 10.3 was quite a bit faster than 10.2 which was quite a bit faster than 10.1 which was tremendously faster than 10.0. 10.4 is expected to keep up this tradition, and from what I've been told, it does address graphics rendering speed. Mind you this is speculation as I haven't used Tiger 10.4 and those that have are under NDA.

    If I were Anand, I'd wait it out. I've used the new dual 2.5. It is noticeably faster than the dual 2.0. However, it is ever so slightly wanting in the Snappiness department. I suspect a dual 3.0 would finally be Snappy. At the same time, software improvements that should appear at the time the 3.0 is introduced might mean that you don't need such brute force to be Snappy. So Anand's dual 2.0 rig might inherit the Snappiness at some point in the not-so-distant future:-)

    BTW, good job on the article Anand. With this subject, you really have to walk a fine line, and I think you did just that.
  • wilburpan - Friday, October 8, 2004 - link

    Disclaimer: I've been a huge Mac fan since back in the day that 128 MB of RAM was considered enough for anyone. Overall, I thought this article was very well balanced in terms of how a Windows oriented user would look at a Mac system. There are two issues that I do have, however:

    1. "...we know our Windows servers, and we know what hardware works best under them, and thus, once assembled and properly maintained, we had no real issues with them." Using familiarity with Windows as a reason for preferring how Windows does things is not quite a valid argument. Substitute the word "BeOS" (to pick a neutral term) for Windows in the above sentence, and you'll see what I mean. For me, I am used to having the close window button in the upper left hand corner. Saying that this is an advantage for OS X because Windows puts the close window control on the other side would be equally invalid.

    2. The issue of viruses and security is never raised. Regardless of the "security through obscurity" arguments people have raised, the fact remains that by their nature, OS X and other *nix-based OS'es are more secure than Windows. Of course, you can obtain a virus program and a firewall program and spend time maintaning those and reset the Windows defaults, but in OS X, you don't have to worry about those things. The criticism is often raised (justifiably) that Macs come underpowered, especially regarding the amount of RAM they are configured with, and complaints are made about the need to spend extra money for RAM. Why similar criticisms about the need to spend extra money for a virus program for Windows aren't similarly raised, especially since the cost of virus programs often are recurring (see Norton AntiVirus' subscription payments for virus definition updates).
  • CindyRodriguez - Friday, October 8, 2004 - link

    #16.. you've never seen a Xeon or Opteron workstation? How many dual P4 or dual Athlon64 boxes have you seen? And don't get me started on comparative performance. G5 are faster than either in some benchmarks and they are slower in others. The PPC 970 is a good chip and if you are going to make comparisons vs. comparitive x86 hardware you should be fair.
    I imagine I've not shown you any problems with the article because you don't know the subject matter. I'm in a PC/Mac support office and we're all having a good chuckle about it.

    #18.. My point isn't that it's a day outdated. My point is that Anand is doing a 1 month look back on a machine that was pulled off the market 3 months ago. My complaint is that though he acknowledges early that the machine has been rev'ed, he carries a tone through the piece that this is the latest greatest and it's not. Look at a dual 2.5 GHz G5 for $3K and compare it do a dual 2.4 GHz Opteron from a good vendor with a warranty and compare those too machines on price and performance. The Opteron will beat it in a lot of benchmarks (due to the rockin low latency mem controller) but It won't destroy the mac on price and I can still find benchmarks where the mac is faster.

    My impression of the article is, Anand didn't bother to do any research and he provides backhanded digs when he has anything nice to say. I understand that the article is the Mac from a PC users perspective, but it would have been much better if he would have written the article as the novice, then did the research and fact checked it as a journalist.
  • raulmot - Friday, October 8, 2004 - link

    Anand,

    You should try using the Mozilla Camino browser if you want a Mozilla based browser with the look and feel of OSX. It was built specifically for the Mac. Firefox added Mac support more as an afterthought.

    That said, I don't use a Mac and don't know what your experience would be like, but I am an avid Firefox user and understand Camino may be more what you're looking for.
  • brain29 - Friday, October 8, 2004 - link

    Of course the article is outdated. Even if he had written it yesterday it would have been outdated. Technology moves very fast nowadays. What's rediculous is that he has had his machine for however long and already you have given him reason to have to spend another 3 grand to upgrade. I know that if I spent that kind of money and found out that they upgraded my system. I'd be pissed. That's one reason I will probably never switch. I don't want to drop that cash on a rig and then be forced to do it again in 2 years. The thing that makes Mac's run so sweet, (proprietary hardware) is the thing that keeps me from gettin one. Ironic?
  • GL - Friday, October 8, 2004 - link

    Calm down Cindy,

    Regarding the .app bundles, you are correct. But I suspect Anand was misled by the installation of Office 2004. In grand Microsoft tradition, they decide to play by a different set of rules. Office installs as Anand suggests. But it's the only application that I know does. The rest are .app bundles like you say.

    Anand,

    Here's a keyboard tip. When you get to a dialog, you typically see 3 options: Cancel, an alternate choice (glowing but not highlighted, i.e. Do Not Save), and the default choice (highlighted, i.e. Save). Escape is for Cancel. Spacebar is for the alternate choice. Return is for the default choice.
  • Kishkumen - Friday, October 8, 2004 - link

    #11 - Whoa, what? Since when is a G5 processor equivalent to a Xeon or Opteron? Anandtech is reviewing a workstation, not server.

    So far your quasi-flames have yet to convince me of one thing contrary to what Anand said in the article. In your own words you're nit-picking, not providing well-supported arguments to the contrary.

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