Underpowered? - or, why the Macbook Air isn't a rip-off. There always seems to be this innate dislike of small notebooks from those who run computer review magazines and web sites. It probably stems from the fact that they often review desktops, and mainly review their laptops inside. They also review machines every week of every month, always reviewing the newest models, and often models that aren't even out yet! They get used to the very highest spec machines and set that as their internal base-line, and Since things change only gradually they obsess over minutia of benchmarks, etc.Seriously, I heard one review call the Intel Core 2 Duo processor used in the new Macbook airs "Long in tooth"! I know, I know, it's been around for several years. The reviewer tested an AlienWare laptop last week with the latest 2.65GHz Intel Core i5 or i7 or whatever... the Core 2 is "old news". It scores 10 points lower in FluffyBench 1.0.5.48 or whatever. But honestly, does it matter? To put it another way - Is Apple pulling one over on us, selling us old technology for premium prices? Or is there more to the story? Let's detour from laptop land for a moment, and talk about another device making headlines recently - the tablet. Everyone has been playing up how awesome the iPad is, and how it is revolutionary and all that. "It puts the internet in your lap", etc. For for all of the press it's received - nobody mentions processor speed, least of all Apple. Why is that? Well, because "users" buy a device to use. Either it works well and smoothly with no problems, and is convenient to use - or maybe it's slow, difficult to use, crashes, or whatever. Normal people just trying to use something don't care about why it's fast or slow. They don't care about why it crashes, or the reason for any other part of their experience being bad. What they care about is their experience, the result of their interaction with the device. Thus, honestly, if you want to write emails, it doesn't matter whether the processor is 10MHz or 5GHz, as long as you can write the emails without being frustrated by the computer. That's why nobody asks "What MHz is this calculator?" Nobody asks the processor speed in their digital TV or DVD player either. It either works well, or it doesn't. The iPad works very well for what it's intended to do, as well as being more than fast enough to run a huge variety of 3rd party software - so nobody really cares about the actual processor speed, memory speed, etc. Yet in actuality, the iPad is processor runs at less than 1GHz. Of course, I'm glossing over the fast that it uses a different type of processor here, but the point remains even if you adjust for that. In fact, I had a computer in 1996 than ran at well under 1GHz, and it was more than fast enough to do email, browse the web, etc. If 1GHz was fast enough then, it should basically be fast enough now. Software should get faster, not slower. Of course more features are added, and that slows things down sometimes, but it should be smart at knowing when features can be skipped, etc. Windows is very bad about this, and thus netbooks running Windows Vista are almost unbearable, even with 2GB of ram! Mac OS is much better, however, and doesn't run things like "DFS Disk synchronizer" in the background when they will never be used. Limiting Factor One of the interesting things you learn in computer science is that the execution speed of a program (how fast it runs) is always bound by a limiting factor. For example, if you have a program that converts video, and the bottleneck is the processing speed, obviously you should increase the processor speed, right? If you do so, the program will run faster. Simple enough, but eventually the processor will be fast enough, and it might be that the disk speed is now the limiting factor. So, you start increasing disk speed. Perhaps the disk speed is now super fast, and the memory speed becomes the limiting factor. There is always something that limits the speed, or else programs would run infinitely fast (and we know that doesn't happen!) So if you have a limited budget, and you want to improve the performance of a computer, there are trade-offs involved. Your job as a designer is to figure out what the best trade-off between various factors is. In the case of a laptop, you have a multi-way trade-off: Size vs. Weight vs. Power vs. Speed vs. Memory vs. Disk vs. Price. So the question is - where can you spend the money to improve the user experience the most? Well, let's give some typical examples
Now, notice something: In most interactive applications User Speed is obviously usually the limiting factor. After that, Network is the next slowest factor. We can't do a lot about network speed, since we already usually have network interfaces much faster than the internet available. For most of these tasks, Disk Speed is next. When you launch a program, the computer has to fetch it from the disk and load it into memory, then it has to fetch all the shared libraries (or DLLs), etc., it uses. Then when the program launches, it will read settings from the disk, and may scan fonts and other files. The processor is more than fast enough to do all these things, it's always waiting on the disk. Even for web browsing and email, the reality is that web browsers cache to disk, and email clients usually keep a local copy of the messages on disk, so these theoretically network bound applications still depend on the disk speed. Even compiling (used in application development), which is very processor intensive, is often still waiting on the disk. 3D applications used to be processor intensive, but most of that work has been offloaded into graphics hardware in recent years, meaning that the speed of the graphics chip is the main determinant in most 3D and video playback applications. Batch applications like Video Compression can eat all the processing power you throw at them. If compressing a DVD for your iPod takes 2 hours on your 1.6GHz Macbook Air, maybe it will only take 1 hour on a 3.2GHz Mac Pro. Obviously processing power is the limiting factor here, and thus end-users will benefit directly from a processor speed increase in this type of situation. This also goes for scientific computing (Difficult math like finding prime numbers, cracking encryption, etc.) - in fact, in these types of applications, disk speeds often don't matter at all. Besides Interactive applications like Spreadsheets and Web browsing and batch processing like video conversion and scientific computing, we also have real-time applications, like Skype Video chats, DVD Playback, MP3 playback, etc. In these types of situations, they need have the resources to run at 100% speed (real-time), or the user experience suffers. Once they have 100% of the resources required, there is no bottleneck. For example, if having a 500MHz processor is too slow to decode a DVD, but a 1GHz processor is enough - does having a 2.8GHz processor buy me anything? No, it will still only play back the DVD as well as the 1GHz chip would. (Assuming 1GHz was sufficient). In other words, if the processor speed is high enough to handle the most demanding real-time applications, then it's "good enough" for almost anyone. Reviewers need to get out of the mindset of "This machine is almost 10% slower than that gaming desktop top I tested yesterday!", and realize two things: 1. Most people replace their PCs something like every 5 years, not every 2 months. This is a common corporate policy as well. 2.When you say "it's not fast enough", you need to include for what. What task is it that the user is trying to do that is either frustratingly slow, or they can't do at all because of the speed? One thing that's not mentioned above is the size of memory. There is a hierarchy of speeds in the modern computer. 1. CPU 2. Cache Memory 3. Memory Speed & Bus Speed 4. Disk Speed 5. Network Speed This is an oversimplified view, obviously, but the speed decreases by orders of magnitude as you move down the list. In fact, memory is usually thousands of times faster than hard drive speeds. Disk speeds are measures in milliseconds. Memory speeds are measures in nanoseconds. Network speeds are typically much slower than disk speeds, especially outside of your local network. This is why applications are designed to cache items retrieved over the network onto the disk, and items retrieved from the disk in memory. (And the processor itself caches items retrieved from memory in it's internal cache!). It should be obvious, therefore, than you want to use memory instead of disk when you can,since it is after all, much faster. But there's a problem. All modern PC operating systems are designed to be able to use hard disk space as if it were memory space. When you load your first program or so, it is loaded into memory by the operating system and runs. As you browse web sites, create fies, etc., additional memory is allocated and used. If all goes well, everything runs at full speed until you use up all the memory. Then some requests additional memory, and the operating system helpfully provides it, even though there isn't anymore left! Like Enron accounts using creative accounting, the operating system shows the programs one thing, but actually does another. Memory the operating system thinks isn't in use is "swapped" out to disk, and when it is needed later, it is restored from disk to memory (or course something else has to be swapped to disk then, if memory is still short!). This is why machines can get not just slow, but intolerably, frustratingly slow when you launch too many programs at once. It's not just that they are all running, taking up processor time, but more than they're causing the disk to churn constantly. Incidentally, Apple's iOS doesn't do disk paging, which is one of the reason it's much faster in general. If there's not enough memory, it kills off some of the programs running in the background instead of playing fancy tricks. This works because iOS programs are designed with full knowledge that they may be killed off at any time, so they are careful to always keep files saved, etc. Back to our point of discussion, looking at the chart of applications above, if you were an Apple designer (or someone building your own PC on a budget), what would you do? The fact is, a Core 2 Duo 1.6 GHz is fast enough to play DVDs, do Skype Video, Facetime Chat, and handle any other common real-time tasks. There's just not much benefit to upgrading the CPU once it's past "good enough", if other parts of the puzzle are lagging behind. What's next? Well the disk is what we're always waiting on for typical productivity apps (after the user), and it's also one of the most common things to break on laptops, so we could upgrade that to SSD. That will speed up many things, save power (thus increase battery life), and decrease maintenance costs and help reduce data loss. After that? We could increase our 3D and Video performance by getting a better graphics chip. Finally? If we still have budget left over, we could increase the amount of RAM, or bump the processor speed a little bit. Now, take a look at what Apple actually did!
As a result, the 2010 Macbook Air machines boot faster than almost any other computer on the market, Mac, PC, or otherwise. Once booted, applications load almost instantly, and are immediately ready to use. Mac OS was already very fast at waking up from sleep mode, but the new Macbook Air models wake up from hibernate mode very quickly as well. Things like 3D graphics that used to strain the 2008 Macbook Air models are now effortless. In other words, the new MacBook Air, even the 11 model, flies. It is very fast to use. Technically, the processor isn't any faster, but the machine itself is faster to use, because the slowest parts of the equation have been optimized. In fact, if you elect for 4GB of memory, you can even run Windows 7 in VMware quite comfortably! For all the whining and benchmarking all the mainstream reviewers did, most of them forgot to mention that this machine is much faster to use than most machines on the market. For example, OpenOffice 3.3.0 launches on the MacBook Air 11 Inch 1.6GHz machine in less than 4 seconds. Numbers launches in 2 seconds flat. Microsoft Word 2011 takes 3-4 seconds to start up and be usable. In fact, the machine takes about 14 seconds from off to fully booted and logged in in most cases. (The slowest time I tested was 20 seconds, after upgrading the OS). Then there's the other thing everyone keeps forgetting: Even if Apple was releasing machines with the exact same specifications, the price keeps dropping. This is to be expected in the computer industry, but Apple is frequently criticized for charging too much. They have an option here, to lower the price, or raise the specs, and they have lowered the price considerably. In 2008, the original Macbook Air cost $1,800 USD without the SSD option, or $2800 with SSD. Now in 2010, just 2 years later, the new comparable model costs $1300, with a faster processor, SSD, better graphics, longer battery life, and an extra USB port. I don't see a lot to complain about here. In the end, basically Apple skimped on upgrading the processor, and decided to upgrade the hard disk, graphics, and battery instead - and you should be glad. But it's not all about speed... Other things you should take into consideration: Pros
Cons Apple did try to save on costs and/or space by taking away features they thought nobody cared about...
Most everything else is the same. |
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