Fresh out the frying pan and into the fire, I just finished my Nexus One review late last night only to have my iPad preorder show up early this afternoon. I had been preparing for it's arrival not by downloading apps but by figuring out what comparative benchmarks I wanted to run on the iPhone 3GS and Nexus One.

As the first device to use Apple's A4 SoC I wanted to see how it stacked up against the Cortex A8 and Qualcomm's QSD8250. All three chips appear to be dual issue in order architectures with varying pipeline depths, clock speeds and cache sizes.

At 600MHz the Cortex A8 in the iPhone 3GS is the slowest out of the bunch. The Snapdragon is much faster as we just established thanks in part to it's 1GHz clock speed. But what about Apple's 1GHz A4?

There's very little we know about the A4 other than it's operating frequency. It is manufactured by Samsung but on an unknown process node. Jon Stokes recently stated that Apple's secrecy surrounding the chip is because it isn't anything special, just a Cortex A8. If that is true, I suspect that it would have to be manufactured at 45nm in order to reach such a high clock speed.

With a new silicon mask there's also the chance that Apple moved to LPDDR2 to boost memory bandwidth; a change that most SoC makers are planning to make this year.

So how does Apple's A4 stack up against today's favorite smartphone brainchild? Keep in mind that these results are generated by running two different OSes (Android 2.1 and iPhone OS 3.2) and two different browsers. What we're looking at is the performance delivered by the combination of the CPU and the software stack:

Applications Processor Performance
  Apple iPad (Apple A4) Apple iPhone 3GS (ARM Cortex A8) Google Nexus One (Qualcomm Snapdragon QSD8250) % A4 Faster than Snapdragon
Load 6.2 seconds 9.3 seconds 8.8 seconds 41%
Load 10.6 seconds 18.0 seconds 11.5 seconds 8.7%
Load 7.9 seconds 13.9 seconds 8.6 seconds 8.7%
Load 7.8 seconds 13.8 seconds 11.0 seconds 39.9%
Load 6.8 seconds 12.3 seconds 8.6 seconds 26%
Load 3.7 seconds 7.4 seconds 4.2 seconds 11.6%
Load 13.8 seconds 22.8 seconds 22.0 seconds 59.4%
Load 14.1 seconds 21.4 seconds 16.7 seconds 18.5%
Load 3.0 seconds 6.0 seconds 2.6 seconds -11.8%

Unless otherwise specified, I loaded the full version of all of the websites above (the exception being CNN, where I used the mobile site). To ensure reliability, I ran all of these tests at least 5 times, threw out any outliers and averaged the rest. The rests were also run at around the same time to ensure that content on the sites was as similar as possible (and thus shouldn't be compared to this morning's Nexus One results). You'll note that the Engadget results are a bit odd. It looks like the iPhone and Nexus One scores are bottlenecked somewhere else (there seemed to be some network issue plaguing the loads, but it wasn't present on the iPad), but if you toss out the very large differences you end up with what I believe to be the real story here. Update: Flash wasn't enabled on any device (not supported on iPad/iPhone, not officially available on Android yet), and all three devices connected to the same WiFi network.  The Apple devices used mobile Safari, while the Android device used the Android Browser.  Both are WebKit based but there are obvious, unavoidable software differences.

Removing the AnandTech, Ars Technica and Engadget loads (which were repeatable, but unusually long) the iPad loads web pages 10% faster than the Nexus One. If you include those three results the advantage grows to 22.5%. I'd say somewhere in the 10% range is probably realistic for how much faster the A4 is compared to the Snapdragon.

I also ran the official WebKit SunSpider JavaScript Benchmark on all three platforms to give us a network independent look at real world JavaScript performance:

If we take the network out of the equation, the A4 in the iPad has a 37.6% performance advantage over the Qualcomm QSD8250. This actually supports some of the larger performance differences we saw earlier. If Apple can manage to deliver this sort of performance in its smartphone version of the A4, we're in for a treat.

The why is much more difficult to ascertain. It could be as simple as the the iPad OS being better optimized than Android, a definite possibility given how much longer Apple has been working on it compared to Google. The advantage could also be hardware. The A4 may boast higher IPC than Qualcomm's Snapdragon thanks to better core architecture, larger caches or a faster memory bus. The likely case is somewhere in between, where the iPad's advantage comes from a combination of hardware and software.

It could also be a power optimization thing. The A4 in the iPad is paired with a much larger battery than the QSD8250 in the Nexus One, Apple may be able to run the SoC at more aggressive performance settings since it doesn't have to worry about battery life as much. Either way the one thing we can be sure of is Apple's A4 SoC is much more like a 1GHz Cortex A8 rather than anything more exotic. Good work Jon :)

I should note that while the performance improvement is significant, it's not earth shattering. Despite the early reports of the iPad being blazingly fast, I found it just "acceptable" in my limited time with it thus far. I'll go into greater detail in my full review later.

This does bode well for the upcoming 4th generation iPhone, which is widely expected to also use the Apple A4 SoC. That upgrade alone should put the next iPhone ahead of Google's Nexus One in performance, assuming that it offers the same performance as it does in the iPad. Pair it with a modernized and feature heavy iPhone OS 4.0 and we might see an Apple answer to Android in 2010.

The A4 is particularly exciting because it combines Snapdragon-like CPU performance with a PowerVR SGX GPU. A much better option than the aging ATI core used in Qualcomm's QSD8x50 series.

With Apple showing its A4 performance this early, Qualcomm also has a target to aim at. The first single-core 45nm Snapdragon SoC due out in 2010 will run at 1.3GHz. That could be enough to either equal or outperform Apple's A4 based on what we've seen here today.

Expect our full review of Apple's iPad as well as more discussion about the A4 next week. Have a great weekend guys.

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  • bsoft16384 - Monday, April 5, 2010 - link

    Exactly. The iPad is not being sold as a smartphone with a bigger screen. It's being sold as an alternative to a netbook or tablet PC, both of which are dramatically faster.

    I just ran SunSpider on an old Athlon XP 1.2GHz laptop (with 512MB of SDRAM and Windows XP). It completed in 2550ms, which is about four times as fast as the iPad.

    No one expects the iPad to be as fast as a netbook. I think that you can legitimately argue that the iPad's performance is perfectly acceptable. What you can't argue is that a device that takes 10 seconds to load Digg (or 14 to load Gizmodo) is "super fast".

    The iPad is faster than a smartphone, but slower than the products (netbooks) it competes with.
  • gubatron - Monday, April 5, 2010 - link

    And why would you benchmark the CPU of a tablet with the CPU of a smartphone?

    It's like comparing the engine of a motorcycle with the engine of a car.

    It beats me how these articles make it to the homepage of techmeme.

    Sorry, but this is trash.
  • dugbug - Monday, April 5, 2010 - link

    It is in context for the chipsets they have in common, and if you read the article you would understand that.
  • joe_dude - Monday, April 5, 2010 - link

    I think the ease of use with the iPad is a given. All I want to know is if it can play games, not Scrabble. Is this a serious gaming platform that it was so hyped to be?

    The big two (personally) are Internet and games. We know it can't do Flash, which is irritating, but I don't play Farmville.

    But games so far suck on the iPad. Plants vs. Zombies? Vector Wars (1980's gaming)? "HD" racing games with washed out backgrounds? I'm not paying $500 to $800 to play with gadgets.
  • Extremophile - Monday, April 5, 2010 - link

    First, Anand, I believe that your test is fair enough and interesting.

    I have read the negative comments, and they can all make their point. But - honestly - comparing apples and oranges is still better than not comparing at all. And no item was downgradede to become a "lemon" in your test.

    Your test gives a "quick and dirty" preview of what we have to expect from coming hardware. Even if we accept the influence of the different hardware and software environmentsof the SoCs, results are quite conclusive.


    What I missed: Whenever I open a web page on a smartphone, the next step is to enlarge it so that I can read the text. This is at least true for normal HTML pages.

    If you add the time needed for this manual "rework" after loading, how would the three appliances compare?

    Maybe, IPad can justify its existence mainly by saving this process step?
  • dentaldoc - Monday, April 5, 2010 - link

    Listening to so many apoplectic responses makes me ponder. Just imagine if the test results had been just slightly different: Nexus 1.5% faster than either of the (bad, mean, corrupt, greedy) Apple products.

    Comment 1: Ah....

    Comment 2: What a great article

    Comment 3: What a fair comparison

    Comment 4: You folks at Anand are AWESOME!
  • longhorntrojan - Tuesday, April 6, 2010 - link

    Are you planning on doing a battery assessment?

    The iPad does not seem to allow you to loop video. :(
  • AdamBv1 - Wednesday, April 7, 2010 - link

    Some other things to take note, the iPhone 3GS, Moto Droid and Palm Pre all have the same processor at 600MHz but when you look at sunspider tests you see something very interesting.

    iPhone: 17k
    Palm Pre: 20k
    Droid: 34k

    The nexus one has a snapdragon (another ARM Cortex A8 running at 1GHz) and gets 14k. Take that 17k the iPhone gets and multiply by .6 and you get the 10k the iPad scores. Run a palm pre at 800MHz and you get 14k for the sunspider test.

    At least to me this says that Apple has a much better mobile browser than Google or Palm, not that the processor is that much better.
  • manicfreak - Wednesday, April 7, 2010 - link

    If one is going to compare a chip from a smartphone and a chip from a tablet, then why not compare it to Pine Trail?

    And I hope Anand stays true to his word from a previous article... about the Cortex A8, which is used in the Apple A4, is dead to him.
  • aka2 - Wednesday, April 7, 2010 - link

    This is the worst review that I saw on Anandtech. This looks like a paid Apple advertisement. Comparing a netbook sized device with a mobile phone sized device and being “surprised” that the netbook sized device is so fast.
    This is like a joke.

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