The Haswell Ultrabook Review: Core i7-4500U Testedby Anand Lal Shimpi on June 9, 2013 9:00 AM EST
I didn’t get my hands on the Haswell S7 until a few hours after I landed in Taipei. My hotel’s in-room internet was throttled to around 2.5Mbps, which wasn’t enough bandwidth to reliably run our web browsing battery life tests. Luckily, I had my review copy of PCMark 8 on hand with its new built in battery life tests. I asked Jarred to run comparison data on the Ivy Bridge S7.
We had time to perform multiple runs on two of the tests: Home and Creative.
From the PCMark 8 Technical Guide:
The PCMark 8 Home benchmark test includes a set of workloads that reflect common tasks and activities performed by a typical person at home. These workloads generally have low computational requirements making the PCMark 8 Home benchmark suitable for testing the performance of low-cost tablets, notebooks and desktops.
The PCMark 8 Home benchmark test contains the following workloads: Web Browsing, Writing, Casual Gaming, Photo Editing and Video Chat.
The PCMark 8 Creative benchmark test includes a set of workloads that reflect tasks and activities typical of more advanced home computer users. With more demanding requirements than the Home benchmark, the PCMark 8 Creative test is suitable for testing the performance of mid-range computer systems. Your system must have a GPU with full DirectX 11 support in order to run all the workloads in the PCMark 8 Creative benchmark.
The PCMark 8 Creative benchmark test contains the following workloads: Web Browsing, Photo Editing, Batch Photo Editing, Video Editing, Media to Go, Mainstream Gaming and Group Video Chat.
As always, I calibrated both displays to the same brightness (200 nits). In the case of the Haswell based S7, I disabled all additional display power saving options in the Intel driver. Keeping in mind the new S7 has a 33% larger battery, I’m presenting both absolute battery life numbers as well as minutes per Wh for normalized comparisons.
The PCMark 8 Home battery life test is the lighter of the two, and thus has the best chance of showing peak improvement on Haswell. The results are very good:
|PCMark 8 Battery Life|
|PCMark 8 Home||PCMark 8 Home (Normalized)||PCMark 8 Creative||PCMark 8 Creative (Normalized)|
|Acer Aspire S7-391 (Core i7-3517U)||2.83 hours||4.857 mins/Wh||3.35 hours||5.743 mins/Wh|
|Acer Aspire S7-392 (Core i7-4500U)||5.2 hours||6.783 mins/Wh||5.12 hours||6.674 mins/Wh|
In both benchmarks, Haswell ULT delivers 11 - 14% better performance and substantially longer battery life. Normalized for battery capacity, Haswell ULT offers 16% better battery life in the Creative test and almost 40% better battery life in the Home test. Note that the performance advantage pretty much disappears once we move to the Balanced power profile with the laptop connected to the wall.
|PCMark 8 Performance|
|PCMark 8 Home (Power Saver)||PCMark 8 Home (Balanced)||PCMark 8 Creative (Power Saver)||PCMark 8 Creative (Balanced)|
|Acer Aspire S7-391 (Core i7-3517U)||1595||2694||1391||2508|
|Acer Aspire S7-392 (Core i7-4500U)||1777||2832||1583||2553|
Update: I made it back to the US, equipped with decent internet speeds, I was able to run our light 2013 web browsing battery life test. The increase in battery life is tremendous:
The new S7 delivers over 2x the battery life of the old model. Normalizing for battery capacity, the improvement due to Haswell is 57.5%. These results track perfectly with what we saw in PCMark 8. Workloads with greater idle time will show the biggest improvement in battery life thanks to Haswell ULT.