You're at your local supercenter and you have two laptops in front of you: one with an Intel Core i7, and one with an Intel Core i5.
Comparing laptop CPUs can be complicated, so which do you choose? Do you go for the one with the supposed increase in power that their tech expert claims it has? Or do you save a few bucks and get the cheaper one?
Worry not, we're here to answer all of your questions. And to do that, we called in two seemingly identical Dell XPS 13 laptops (1080p display, 8GB RAM, 256GB SSD). The difference being that one is outfitted with an Intel Core i7-8550U, and the other has a Core i5-8250U. Let's see how they stack up.
Intel Core i5 vs. Core i7: Benchmark Results
| Row 0 - Cell 0 | Core i5 | Core i7 | Ultraportable Notebooks Average |
| Geekbench 4 | 13,179 | 13,995 | 12,941 |
| HandBrake | 18:28 | 17:19 | 20:21 |
| Excel | 1:12 | 1:09 | 1:28 |
| 3DMark Ice Storm Unlimited | 78,801 | 83,684 | 78,827 |
| Battery Life | 10:51 | 10:49 | 9:06 |
Clock Speed and Price
While the Intel Core i5-8250U and Core i7-8550U are both quad-core processors with the ability to process eight threads simultaneously, their clock speeds are slightly different. The Core i5's clock speed is set at 1.6-GHz (3.4-GHz with Max Turbo), while the Core i7's is faster at 1.8-GHz (3.6-GHz with Max Turbo). The Core i7 also has a bigger processor cache at 8MB, compared with the Core i5's 6MB. Intel's SmartCache determines how much space there is in the processor to remember particular functions and to carry them out faster than usual.
The numbers seem pretty minuscule, but how much are those numbers going to cost you? Well, the two XPS 13s that we tested currently cost $1,759 (Core i5) and $1,959 (Core i7), creating a $200 price gap. The $200 delta continued when I configured the Acer Aspire 5, but when configuring the Lenovo ThinkPad X1 Carbon, I saw only a $150 difference.
Overall Performance
To test a laptop's overall performance, we use a synthetic benchmark called Geekbench 4. The XPS 13's Core i5 CPU scored 13,179, narrowly beating the 12,941 ultraportable notebook average. However, the Core i7 didn't make a significant difference with its score of 13,995, which is a 5.8 percent increase from the Core i5.
Video Transcoding
On the HandBrake benchmark, which tests how long it takes a machine to transcode a 6.27GB, 12-minute-and-30-second 4K video to 1080p, the XPS 13's Core i5 CPU took 18 minutes and 28 seconds, which slides past the 20:21 category average. The Core i7, however, did it in 17 minutes and 19 seconds, putting a 1:09 (6.2 percent) gap between them.
Excel Test
To pile on the stress to the CPUs, we put them up against use our Excel test, which requires them to match 65,000 names and addresses. The Core i5 CPU knocked it out in 1 minute and 12 seconds, 16 seconds faster than the 1:28 category average. The Core i7 did it a only few seconds faster, at 1:09, for a mere 4.2 percent difference.
3DMark Ice Storm Unlimited
Although you're not going to be taking on Witcher 3 with the Intel UHD 620 GPU inside these two XPS 13s, there are plenty of AAA titles that these two can handle. But which does it better?
On the 3DMark Ice Storm Unlimited benchmark, which tests the overall graphics performance, the Core i5's GPU hit 78,801, falling just short of the 78,827 ultraportable notebook average. Meanwhile, the Core i7 nailed an 83,684, effectively making it 5.8 percent better than the Core i5, which is the same exact increase as the general performance.
Battery Life
With great power comes great power consumption, so we decided to test that by having each laptop continuously surf the web over Wi-Fi at 150 nits of brightness. The Core i5 lasted 10 hours and 51 minutes, sailing past the 09:06 ultraportable notebook average. However, the Core i7 stood its ground and survived for 10 hours and 49 minutes, making an unnoticeable 0.3 percent difference to the Core i5.
Which Intel CPU should you get?
Although the Core i7-8550U beat the Core i5-8250U fair and square, it really wasn't by much. At most, the Core i7 is only 6 percent faster in overall performance, which is quite underwhelming when you consider the price difference. A single minute spared during video editing certainly isn't worth $150 to $200.
If you work in a field that requires you to run taxing programs all day, it may be of use to you. However, the money would be better spent on upgraded storage space, a higher-resolution display, or even a discrete GPU for gaming.
