The iPad and its Performance

Apple knows how to make things feel fast. It’s all about making animations as smooth as possible and making sure that the UI always responds consistently. Apple isn’t perfect in this regard, but it does pay more attention to detail here than most other companies.

On the iPhone, scrolling is always smooth, swiping between home pages feels quick, apps launching are always well animated. The same is (mostly) true for the iPad, but thanks to a faster processor, many of these animations are physically faster. Bringing up the home screen is lightning quick, as is swiping between them. Scrolling is also very smooth, so much in fact that I found myself scrolling through emails and pages just because the animation was done very well.

There are some rough edges of course. While swiping between home screens is nice and fast, bringing up the quick search screen is choppy (not Android choppy, but choppy for the iPhone OS). The same is true for some other apps, particularly 3rd party ones. The latter point makes sense given that developers haven’t had much time with the device, but Apple not ensuring a perfectly smooth UI across the entire OS is telling.

Apple tends to move engineering resources around the company. The iPhone launch delayed the OS X launch that same year. And the iPad launch surely had some impact on other products. Or is it the other way around? Later this week we’ll see Apple preview version 4 of the iPhone OS, which implies a release sometime in the coming months (June?). An on-track iPhone OS 4 release could explain some rough edges with the shipping iPad, as well as why we don’t seem to have a plethora of amazing apps from Apple at launch.

Despite my nitpicking, this thing is definitely faster than the iPhone 3GS and even the Google Nexus One. Surfing the web, loading applications or generally just interacting with the device. Going to a 3GS from a Nexus One feels slow, going to a 3GS after using the iPad just feels wrong.

But with a larger screen you get the desire to want to do more and expect more from the iPad. I would say that in this sense the performance is a letdown. The A4 is speedy but not quite fast enough for this size of device.

  iPad (Apple A4) Google Nexus One (Qualcomm QSD8250) iPhone 3GS (ARM Cortex A8) iPhone 3G (ARM11)
Manufacturing Process 45nm 65nm 65nm 90nm
Architecture In-Order In-Order In-Order In-Order
Issue Width 2-issue 2-issue 2-issue 1-issue
Pipeline Depth ??-stage ??-stage 13-stage 8-stage
Clock Speed 1GHz 1GHz 600MHz 412MHz
L1 Cache Size ?? ?? 32KB I-Cache + 32KB D-Cache 16KB I-Cache + 16KB D-Cache
L2 Cache Size ?? ?? 256KB N/A
GPU PowerVR SGX Adreno 200 PowerVR SGX PowerVR MBX

To figure out where the iPad falls in the grand scheme of things I ran a number of web page load tests and browser benchmarks. To remove the internet from the equation, I loaded all pages off of a server on my own network. This is as close to a pure CPU and OS/browser benchmark as we’ll get.

Given that the iPad runs off smartphone hardware, the obvious comparisons are the iPhone 3GS and Google’s Nexus One. The former is based on a 600MHz Cortex A8, while the latter uses Qualcomm’s 1GHz Snapdragon QSD8250 running Android. Oh and there’s just one more thing:

This is ASUS' Eee PC 1001P. Priced below $300 it is the epitome of the netbook. Low cost and functional, but without looking overly cheap. Based on Intel’s Atom N450 processor this should put things in perspective. I ran the same set of benchmarks on it that I ran on the rest of the platforms. I used Chrome running on Windows 7.

  Apple iPhone 3GS Google Nexus One Apple iPad ASUS Eee PC 1001P
AnandTech Front Page 4.5s 4.3s 3.1s 1.2s
CNN Front Page 5.4s 4.4s 3.9s 2.8s
CNN Front Page 3 8.7s 6.8s 6.3s 3.5s
Facebook 2.5s 2.4s 2.0s 1.4s
MSN 10.5s 5.1s 5.0s 2.8s
Yahoo! 1.9s 1.6s 1.4s 0.8s
Engadget 15.0s 11.6s 11.1s 4.8s

To make this data easier to read I averaged all of the numbers for each device, normalized them to the iPhone 3GS (in terms of % faster) and put the data in a graph:

And now you see why I said the A4 does well against smartphones, but doesn’t cut it for the screen size of the iPad. While the iPad is 46% faster than the iPhone 3GS and 14% faster than the Nexus One on average, the Eee PC is 87% faster than the iPad. It is noticeable!

Real world JavaScript performance is also no contest between the A4 and Intel's Atom:

If Apple doesn't have plans to use Moorestown (or a derivitive) in its iPad at some point, I would be sorely disappointed in the company's ability to make intelligent hardware decisions.

I will give Apple credit, the iPad feels quick in most cases, which is probably why the sacrifice to go with a lowly Cortex A8 was made. However, when it comes to browsing the web, there’s a tradeoff. It’s much better reading web pages on the iPad, but it’s much faster on the Eee PC.

The comparison gets more complex when you look at things like application launch times. It takes the iPad 3 seconds to launch Pages, and less than 1 to launch Safari. If the application was previously in memory, the Eee PC can fire up Chrome in less than a second, otherwise it takes longer depending on what Windows decides to do with the disk at that moment. And launching Word from scratch takes much longer than 3 seconds.

Apple is relying on solid state storage and a very lightweight OS while netbooks usually have terribly slow hard drives and a bulky software stack. It’s a ginormous tradeoff. Web pages load quicker on a netbook, but are easier to read/navigate on the iPad.

What Apple absolutely needs in here is an Atom CPU. Apple buys itself a lot of leeway by using a very lightweight OS, but when a web page still takes a dozen seconds to load - you feel the pain. While I realize that Atom hasn't been suited for such an application until now, there's no reason Apple should've picked the A4 over Moorestown. Moorestown can fit in devices far smaller than the iPad, and would make this thing perform more like (and better than in some cases thanks to the OS) a netbook. I laughed when Jobs said that netbooks don't do anything well. While I'd agree a lot of the time, here they do seem to load web pages faster than the iPad.

The Silicon - Meet the A4 Honest Apple: Battery Life
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  • vol7ron - Wednesday, April 07, 2010 - link

    There's been rumors the iPhone 4g will be talked about tomorrow by Apple. Do you have any insight into this?

    vol7ron
    Reply
  • Griswold - Thursday, April 08, 2010 - link

    http://en.wikipedia.org/wiki/4g Reply
  • vol7ron - Thursday, April 08, 2010 - link

    I don't understand the point of this link?
    Perhaps you want to look at: http://en.wikipedia.org/wiki/IPhone

    Data Network Technology and iPhone technology are not synonymous.
    Reply
  • A5 - Thursday, April 08, 2010 - link

    Unless AT&T has suddenly deployed a 4G network (or they're going to Sprint), then this new phone isn't going to be called the iPhone 4G. Also, the stuff they're announcing tomorrow are the features of iPhone OS 4.0, not new iPhone hardware. Reply
  • vol7ron - Thursday, April 08, 2010 - link

    I'd rather not hear about the hardware at this point, but it'd be nice to say that Apple would up the clock on the 3GS (what I have). Hearing about the OS 4.0 is nice.

    I thought the "G" has nothing to do do with the wireless technology network. While they both stand for "generation", Apple's iPhone/OS pair will still be called the iPhone 4G, regardless if it runs on 3G Network or CDMA technology, or if the OS is upgraded afterwards; if this is confusing, think about the iPhone 2G - it runs on the 3G network and can be upgraded to OS 3.0, but it is still a iPhone 2G due to the initial hardware/OS release.

    -----

    The developer meeting was actually quite nice. There were a few surprises, but nothing huge - just a bunch of much-needed updates :) There will more-than-likely be a few more OS4.0 goodies come June with the official iPhone 4G release.
    Reply
  • Internet User - Thursday, April 08, 2010 - link

    That's incorrect. The naming conventions that Apple typically uses were thrown out the window. The first generation iPhone runs on the 2G EDGE network. The 3G (second gen) and 3GS (third gen) both run on the 3G network. We don't know what the fourth iteration will be called. It won't run on a 4G network, but it will be the 4G iPhone. Reply
  • vol7ron - Friday, April 09, 2010 - link

    Perhaps you are right, but I thought I remember hearing Jobs talk about the naming that went into the iPhone.

    Technically, I think that what happened supports your argument, but we've all seen companies change their logical naming patterns. The first iPhone, as with any first generation, was called the "iPhone", with no suffixed 1G or 2G. It wasn't until the 3G came out (on OS 2.0), where there was question about its name. I think what was talked about was that the beta versions were considered 1G; the first retail release was considered 2G; and the second was 3G.

    The 3GS is where it really breaks that argument, because the 3GS was released with 3.0, so technically it would be called the iPhone 4G. Instead they stuck with the "3G" and added the "S", which they said stands for "speed". However, those "2G" phones that were upgraded to OS 3.0, still work with the 3G network, but are still considered "iPhone" (w/o the suffix, but still unofficially: iPhone 2G).

    In either case, I'm willing to say that I'm wrong, since a lot of it is vague memory. That, and the fact that this article is about the iPad and not the iPhone :) I was just a little curious about OS 4.0, but I was offered an exclusive direct link on the developers briefing, so I found everything out anyhow.

    vol7ron
    Reply
  • nilepez - Thursday, April 08, 2010 - link

    I don't know about AT&T, but Verizon began testing LTE last year and is deploying LTE in some markets this year. Until Apple announces they're partnering with Verizon (or Sprint) or we see FCC submissions, I'll assume it's vaporware....and frankly, I'm not switching from my Sero plan for a phone. Reply
  • vol7ron - Wednesday, April 07, 2010 - link

    Page 2: Since this isn't the 1980s, the iPad only has three four physical buttons on the device.

    I might be reading it wrong but the "three four" seemed out of place. Maybe that was supposed to be a "three or four", or perhaps you were going to come back to it?

    vol7ron
    Reply
  • vol7ron - Wednesday, April 07, 2010 - link

    Page 5: "Tap it twice while you're playing music and playback controls appear, Also when..."
    Perhaps there should be a period where the comma is and a comma after "Also"?

    BTW, not purposefully checking for errors, just looking out for ya.
    vol7ron
    Reply

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