Late 2013 MacBook Pro review: CPU performance

▼ No more bottlenecks: the late 2013 MacBook Pro reviewed

Over the next few days, I'll publish my review of the new 13" MacBook Pro here in several installments. This is the second one, looking at CPU performance.

Late 2013 MacBook Pro review: CPU performance

Every time I bought a new computer, it was faster than the previous one. Sometimes by a lot, sometimes by a little. What I'll be doing here is compare the new MacBook Pro to my old mid-2011 MacBook Air. I paid extra for the upgrade to a 1.8 GHz Core i7-2677M CPU. This CPU has 4 MB L3 cache, and although it's advertised as a 1.8 GHz part, it actually runs at 2.6 GHz with both cores active, and turbo boosts to 2.9 GHz when only one core is running.

The new MacBook Pro has a 2.4 GHz Core i5-4258U CPU with 3 MB L3 cache. I haven't been able to find any information on which turbo ratios apply to the 2.4 GHz frequency with two cores in use, but it looks like this is also 2.6 GHz. The maximum CPU frequency (when using one core) is 2.9 GHz, same as the Air.

You can monitor the CPU frequency and power use of your Intel CPU with the Intel® Power Gadget. (Update 2019-7-1: the link doesn't work anymore, but find new links and more background info on the Powergadget in this PCGuide article.)

But let's have a look at some benchmarks first.

Geekbench 2 32-bit

MBA: 5861
MBP: 7110 +21%

Geekbench 3.1.2 32-bit single core

MBA: 2291
MBP: 2703 +18%

These numbers are not particularly exciting, especially considering that I went from a two-year-old "Air" to a brand new "Pro" machine. However, things are better for certain benchmarks and real-world tasks:

Geekbench 3.1.2 32-bit multicore

MBA: 4316
MBP: 5640 +31%

Handbrake 0.9.9 SD video conversion

MBA: 134 seconds
MBP: 96 seconds, 40% faster

Handbrake 0.9.9 HD video conversion

MBA: 270 seconds
MBP: 157 seconds, 72% faster

QuickTime QuickSync HD video conversion

MBA: 131 seconds
MBP: 48 seconds, 2.7x faster

Unfortunately, using QuickTime to convert to 480p, 720p or 1080p using the respective presets, which uses QuickSync, does result in really large files, so in practice it's not all that useful.

Cinebench 15 GPU

MBA: can't run the test
MBP: 20.02

When running the Cinebench benchmark with 4, 2 or 1 CPU threads, it becomes clear that the MacBook Pro is much better at multithreaded tasks:

Cinebench 15 CPU, 1 thread

MBA: 98
MBP: 106 +8%

For some reason both computers stick to a 2.6 GHz CPU frequency most of the time even under single threaded loads. It looks like MacOS doesn't make the second core sufficiently idle to fully benefit from the turbo boost.

Cinebench 15 CPU, 2 threads

MBA: 137
MBP: 195 +42%

Cinebench 15 CPU, default number of threads (4)

MBA: 187
MBP: 262 +40%

The MacBook Pro can do 1.9 times as much work when using both cores, but the MacBook Air only sees a 40% improvement when going from using one to using two cores. The Power Gadget shows why:

The MacBook Air runs into its power limits very quickly when using both cores fully, so the CPU clock has to be throttled back significantly below the maximum 2.6 GHz. Interestingly, the MacBook Air and the MacBook Pro use roughly the same amount of power with the CPU at full utilization: the MBA a little over 20 W, the MBP a little under. However, for the Air this is above its 17 W Thermal Design Power (TDP), so it quickly throttles back the CPU frequency. The MacBook Pro's TDP is 28 W, so it can run at full blast with thermal room to spare.

The fan speeds reflect all of this. When using 400% CPU time (such as when encoding video with Handbrake), the MBA's fan quickly spins up from its regular 2000 RPM, eventually reaching 6500 RPM, which is quite noisy. The MBP's fan runs at 1300 RPM under normal circumstances, and didn't go beyond 2200 RPM with the CPU at 400% for some time, which is barely audible.

Last but not least, let's have a look at OpenCL (not to be confused with OpenGL) performance. Apparently Apple is leveraging OpenCL for more and more tasks. One of the GPUs in the new Mac Pro doesn't even drive any displays and is just there for number crunching.

Unlike most programs, which run on the CPU, or OpenGL, which runs on the GPU, OpenCL programs can run on the CPU and most GPUs, or even on both at the same time. The Luxmark OpenCL benchmark is a bit (14%) faster on the MBP's CPU than on the MBA's CPU.

Luxmark 2.1beta2 OpenCL benchmark, CPU

MBA: 181
MBP: 207 +14%

The MacBook Air has Intel HD 3000 graphics on board, which doesn't support OpenCL. The HD 5100 Iris GPU that's part of the the MacBook Pro's CPU die does, and this is 78% (!) faster than using the CPU.

Luxmark 2.1beta2 OpenCL benchmark, GPU

MBA: -
MBP: 368

Unlike the CPU, the GPU has no problem pushing the i5-4258U past its 28 W TDP, so it has to throttle back after 20 seconds or so. Note that this is with the CPU mostly idle.

Using the CPU and GPU together increases performance another 9%, for a total of 121% over the maximum the MacBook Air can do.

Luxmark 2.1beta2 OpenCL benchmark, CPU+GPU

MBA: 181 (CPU only)
MBP: 401 +121%

I have to be honest: this comparison started from a place of disappointment. Intel didn't move the needle much regarding single core performance on an identically clocked system. (However, two years ago I had to pay extra to get the 1.8 - 2.9 GHz i7, while the 2.4 - 2.9 GHz i5 is now in the base configuration.) But the extra thermal headroom, and probably the faster memory (but less level 3 cache), allows the new Haswell CPU to push ahead in multithreaded performance, which should benefit most number crunching type applications, such as video encoding. And applications that make use of OpenCL and thus the much beefier GPU should benefit a lot. So I'm still reasonably happy with the performance of this computer.

Permalink - posted 2013-10-30

Late 2013 MacBook Pro review: battery life

▼ No more bottlenecks: the late 2013 MacBook Pro reviewed

Over the next few days, I'll publish my review of the new MacBook Pro¹ here in several installments. This is the first one, which looks at battery life.

¹ This is of course the Intel Haswell-powered MacBook Pro "with Retina® Display", but the latter pretty much goes without saying now. Which is a good thing, because I really dislike (mis-)using the word "retina" to indicate a high resolution screen, especially when capitalized. I got middle stock model: 8 GB RAM, 256 GB SDD, 2.4 GHz CPU.

Late 2013 MacBook Pro review: battery life

Many of a computer’s features reveal themselves in only a few minutes or even seconds of use. That is not exactly the case for battery life. The amount of time you can work on a battery charge also varies wildly with the type of use. So Apple's claim that this computer can work on battery power for 9 hours was one of the first things I wanted to test. Here are the results of three tests I did.

My first test is the "wait for mail" test. This is the lightest possible workload, so it should provide an upper limit on battery life you can expect. The computer has bluetooth and Wi-Fi on, the screen is set to the lowest non-off brightness, sleep and the screensaver are turned off, and only two applications are open: Mail and Messages. When I went to the System Preferences to turn off sleep, I was a bit confused. Did the Energy Saver pane always look like this?

No, it didn't. Mouse over the image to see the energy pane looks like on my mid-2011 MacBook Air that's also running OS 10.9. (Or click here for the one on the MacBook Pro or here for the one on the MacBook Air.)

(Turns out that when using the power adapter, you can keep the computer from sleeping when the display sleeps, but there's no setting for how long until the computer sleeps.)

So after removing the sleep light a few years ago, Apple took the next logical step and simply lets the entire computer sleep very soon after the display goes to sleep. Which of course helps you get even more battery life. However, this is not so great when it comes to mail and IM clients and the like that run in the background and monitor what happens over the network. But this can be remedied with tools like Wimoweh, that make sure the computer doesn't sleep when you don't want it to. Or maybe not... I was still able to ping the computer even though the caps lock light on the keyboard had turned off, presumably indicating that the computer had gone to sleep.

In this setup, clicking on the battery icon in the menu bar showed that the system expected to be able to run for 20 hours. I had prepared the test setup before I went to bed. I woke up early 6 hours later, but the battery still showed a 100% charge and 20 hours left. After running for 8 hours, this had dropped to 74% and 14 hours, 45 minutes. I checked every hour from then on, and in each case, the battery had depleted another 4%. After 12 hours, I ended the test with 58% charge left in the battery, because I wanted to actually use my brand new computer for something.

Wait for mail: 24 hours (!)

Verdict for the "wait for mail" test: it seems the battery charge percentage wasn't calibrated correctly when full. But this computer can easily run 12 hours on the battery if it's not really doing anything, and probably as much as 24 hours.

Watch video: 6 - 12 hours

The next test was watching video. I tried a few different types of video and looked at the battery percentage to evaluate the battery's performance to avoid having to spend a week running battery tests. For these tests I set the screen to half brightness and turned off Wi-Fi. (I think I forgot to turn off bluetooth.) Headphones were connected for the audio at a quarter volume.

First I wanted to see how this machine handles viewing DVDs. But... it doesn't have a DVD drive! So I hooked up Apple's external USB Superdrive. At first it seemed that this wasn't the best possible idea, as during the first few minutes of watching the DVD the drive was very noisy. But after that, it spun down and only spun up in a more modest fashion momentarily from time to time. Playing back a DVD for 1.5 hours used up 16% battery charge. So it should be possible to watch DVDs for a little over 6 hours.

But obviously this isn't a very realistic test. If you're going to watch a DVD on a computer with only an external optical drive, you'd rip the DVD beforehand and then play the ripped DVD from the internal SSD drive. This is what I did starting at 8% battery capacity left. 45 minutes later, the computer went to sleep. So this means the computer should be able to play back ripped DVDs for more than 9 hours on one battery charge.

Then I played back a movie in 1080p HD resolution in H.264 format. Two hours of this used up 17% battery capacity. So the computer should be able to play back HD video in GPU-accelerated H.264 format for nearly 12 hours on a single battery charge.

Normal use: 9 hours, 42 minutes

Last but not least: how long does the battery last during more typical use? Many professional reviewers have test setups where a script loads a website every 15 seconds or something like that. The good thing is that this makes for a consistent, repeatable test. But it's not real use. What I did is use the computer like I do normally, with two slight tweaks: I made sure I had the computer do something pretty much the entire time, and display sleep was set to "never". I played music most of the time, either using the built-in speakers or streaming over the network to my Apple TV. Most of the time I was writing or reading web pages in Safari, but I also turned on Filevault at some point, so the computer had to encrypt its entire "256" GB SSD.² The computer also slept for 12.5 hours, which used up 3% battery charge. Most of this test was done at night with the screen at low brightness.

When awake, the MacBook Pro used 10 - 12 % battery per hour. Ultimately, it went to sleep after 9 hours and 42 minutes of use. So Apple's battery life claim of 9 hours is completely justified. Obviously, you're not going to get this kind of battery life doing things like video encoding. On the other hand, you can make the battery last longer by not playing music and otherwise minimizing background tasks.

At IETF meetings, there are always power strips strewn throughout the meeting rooms. A decade ago, I'd always connect my laptop to power whenever I could, and run a few hours on the battery otherwise. More recently, I wouldn't bother to connect the power adapter during the morning session, but I'd have to do so during the afternoon sessions at some point. I think with this computer I could easily leave the power adapter in my hotel room and run on the battery the entire day. I typically don't stay in the conference hotel, so this would be taking a slight risk. But with more than a thousand Internet engineers around you can probably bum fifteen minutes of charging in a pinch...

Speaking of charging: the included 60 Watt power supply charges the battery at about 1% per minute, but this slows down after reaching 80%, so charging from dead to full takes two hours. In other words, much the same as charging an iPhone.

Conclusion: the battery life is everything Apple promises and then some. You really don't need to forego the high resolution screen and get a MacBook Air if you want extremely good battery life.

² The SSD holds 250,140,434,432 bytes.

Permalink - posted 2013-10-28

Late 2013 MacBook Pro review: CPU performance

Late 2013 MacBook Pro review: CPU performance