A Month with a Mac - Part II: The Mobile Experienceby Anand Lal Shimpi on January 24, 2005 12:01 AM EST
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What's Changed Since Part I
Dual 2.5GHz G5Just like AMD and Intel, IBM also made the transition to 90nm with their PowerPC 970FX processor, or as it's known in the Apple world, the G5. The 90nm G5 allowed for a pretty impressive jump in clock speed, from the previous 2.0GHz limit to 2.5GHz. The 25% increase in clock speed per chip puts the G5 within striking distance of AMD, whose Athlon 64 FX currently tops out at 2.6GHz. Clock for clock, AMD does have an advantage over the G5 (thanks, in part, to the Athlon 64's on-die memory controller); however, in the GHz race, Apple is at least catching up despite not breaking any speed records. As I discovered in the first Mac piece however, pure performance extends far beyond the clock speed of the CPUs and, often times, rests on the shoulders of the OS. So, more important than the 2.5GHz G5's comparison to the Athlon 64 is its impact on performance in OS X - which is nothing short of positive.
Having tested the new $3000 G5 extensively, the speed bump to 2.5GHz actually does result in a much more responsive system. The 25% increase in clock speed translates into a very perceivable real world performance improvement, even actually taking my focus away from things like slow smooth scrolling, thanks to improvements in the overall responsiveness of the system. Also remember that because the FSB clock scales with CPU speed, you get much better CPU scaling on the G5 than you do with more conventional architectures. In the case of the 2.5GHz chips, effective FSB speed goes up to 1.25GHz, offering more bandwidth than even the Pentium 4's 1066MHz FSB.
Because of thermal density issues, the dual 90nm 2.5GHz G5 workstation is actually water cooled, which marks an interesting milestone for Apple - offering the first widely available, water-cooled, straight-from-the-OEM computer. The water cooling system on the new 2.5GHz G5 is interesting, but it doesn't make the system any quieter than the dual 2.0 that I used in the original Mac article. The rest of the new system remains the same, which makes me wonder if Apple's release of Tiger will showcase the introduction of a more widely updated system with much more than faster CPUs (e.g. PCI Ex-press graphics support). But, more on Tiger in a bit...
With the release of the dual 2.5GHz Power Mac, Apple has made some interesting changes to their workstation/desktop lineup. As I just mentioned, the high end still costs $3000, but the platform I reviewed in the first article has now dropped down to $2499 ($2299 with educational discount). Even at $2299, although system prices are getting more reasonable, it's still higher than what most PC users will consider. Things get very interesting when you look at the lower end of the spectrum, more specifically at the single and dual 1.8GHz Power Mac offerings. Priced at $1499 and $1999 respectively, the single and dual 1.8GHz Power Macs are finally getting into more reasonable price points. With Apple's student discount (which is available from their online store), the prices drop to $1349 and $1799 accordingly. At $1349, a single 1.8GHz G5 is a tempting offer to someone looking for a mid-range workstation, but how does the single CPU compare to the dual setup that I used in the first article?
For starters, the clock speed difference isn't tremendously noticeable - the difference is only 10% on paper and even less in the real world. I'd venture that the 1.8GHz G5s are about 5 - 6% slower than the 2.0GHz chips, at best. The biggest performance impacts here are: 1) memory size, and 2) the lack of two CPUs. Both 1.8GHz systems ship with a default of 256MB of memory, which unfortunately just doesn't cut it for OS X. Even if you're doing light multitasking, you'll find yourself bogged down by the CPU with only 256MB of memory. When I was testing for the first article, I found myself enamored with how quickly and how well OS X would use up whatever memory I threw at it, so I had no problem going from 512MB up to 6GB in the G5 for my original article. Since then, I've played around quite a bit with memory sizes and found that the sweet spot for OS X really is around 512MB; 1GB, if you are a heavier multitasker. But Apple's biggest mistake at the lower price point systems is to only offer a base configuration of 256MB of memory.
The next issue is going from two CPUs down to one. The strengths of OS X when it comes to multitasking are definitely still there regardless of how many CPUs you have. The fact of the matter is that OS X's multitasking strengths don't only come in its management of concurrent tasks that are eating up CPU time, but rather in its management and ease of accessibility of concurrent windows of applications. From that standpoint, the move down to a single CPU isn't a huge loss; however, you definitely notice the difference between one and two CPUs just as soon as you start performing multiple CPU intensive tasks at the same time. For example, the first time that you start up your machine, there are a handful of programs that you may want to open. Clicking on five or six icons and letting all of the programs start at the same time on a dual G5 vs. a single G5 is like night and day. The same comparison can be made on the PC side of things too, if you've ever gone from a dual CPU system down to a single processor one. Regardless, my recommendation at this point for trying out a OS X machine as a true work system would be a dual 1.8GHz unit with at least 512MB of memory.
iMac G5Also since my original experiment, Apple has released their new iMac G5 - effectively their new desktop line of G5 based systems. The styling of the iMac G5 is definitely a plus, but the highly integrated nature of the system is quite possibly the most attractive aspect of its styling. It's always nice not to have any cords on your desktop.
Internally to the iMac G5, you essentially have a compressed 1U server and if you've ever opened one of these puppies up, that's the first thing that will come to your mind. Even the two DIMM slots are slanted at a 45 degree angle, just like they are on 1U server motherboards. Essentially, all Apple did with the iMac G5 was take their Cinema Display and stick a 1U server motherboard on the back of it, obviously with better exterior styling. The end result is impressive, except for the fact that even the 20" iMac G5 only comes with 256MB of memory standard. By far, the slowest part of using the 20" iMac is dealing with disk swapping, but as soon as you put more than 256MB of memory in there, the machine becomes a pretty decently fast system (as it should for $1899).
The integrated GeForce FX 5200 Ultra isn't the best GPU in the world, which is a bit of a shame, since there's no upgrading it. The built-in 64MB of memory is good enough for smooth Exposé with mild mannered multitasking, but if you find yourself with tons of windows open, you're going to wish that you had an open AGP slot.
The monitors themselves are top of the line, as is usually the case with Apple's displays, with the 20" offering a good deal of real estate and the 17" being surprisingly decent as well. Personally, I felt cramped by even the 20" display's 1680 x 1050 resolution, but also remember that at the time, I was used to running two displays: a 23" and a 20" Cinema Display.
Of the three iMac G5 models, the mid-range $1499 17" 1.8GHz model is the one that I felt was the best overall value as it offered a slightly better system responsiveness than the 1.6GHz system while not being quite as expensive as the 20" unit. Obviously, with a system like the iMac G5, you're tied into the display, so the resolution better be something that you are comfortable with; otherwise, it's time for a new computer for you.
Mac miniThe more recently announced Apple's Mac mini has been turning some heads, even in the PC world. If the iMac G5 is basically a 1U server attached to a monitor, the Mac mini is basically a reorganized laptop without a monitor. If you take Apple's PowerBook G4 and remove the display, keyboard and mouse, you'll find that it's not too difficult to reorganize the motherboard, optical drive and hard drive in such a fashion that you'll be able to fit it into a 6.5" x 6.5" x 2" box. But price it at $499 and then finally, you'll be able to tempt some PC users over into trying it out as their second system.
The Mac mini is especially relevant to this article because a lot of the discussions about performance with regards to Apple's PowerBook will apply directly to the Mac mini, as the two platforms are very similarly configured.
For years, we've been telling OEMs that if they want to truly make an impact on the PC market, they need to do more than just put another ugly gray box in front of end users. Shuttle was the first to actually realize this and has profited tremendously because of it with their XPC designs. But even now, their XPC designs are becoming too conservative, especially when compared to something like the Mac mini. The styling elements and the extremely small size of the Mac mini are what will make the majority of the market consider it. Apple did a very good job of producing, essentially, the iPod of computers with the Mac mini.
For those of you interested in the Mac mini's performance, pay close attention to the performance sections of this article.
OS X TigerThe more I read about OS X Tiger, the more interested I become. The two main features that draw me to the update are Apple's system-wide, fully indexed search engine, called Spotlight, as well as the fact that in Tiger, every single pixel on the screen will actually be rendered by the graphics card. For the most part, in OS X Panther (10.3), all of the rendering work is done by the CPU, with some GPU accelerated compositing occurring. In Tiger, everything is done through the pixel pipelines of your GPU, increasing the dependency on a graphics card with fast memory access, as well as increasing the flexibility of some of the effects that you're able to do in the OS itself.
Given Tiger's reliance on very high GPU performance, I would almost expect Apple to celebrate its release with a new G5 platform - with PCI Express graphics. That may be a bit of wishful thinking, but anything is possible. Despite the fact that Apple does let a fair bit of information outside of their corporate walls, all of their partners are as silent as can be about sharing information out of fear of jeopardizing their relationship with Apple. The fear is understandable - it wasn't too long ago that ATI fell out of favor with Apple for pre-announcing a video card win with Apple at the time.
I've played around with betas of Tiger, none of which were terribly stable or polished for that matter, but the features demonstrated at Mac World do seem to be on the right track for making OS X an even more productivity-oriented OS.