System Performance
Let's move on to performance. Like a lot of base model ultraportable configurations, the LG Gram starts with an Intel Core i5-8250U and 8GB of DDR4-2400 in a dual channel configuration. We haven't spent a lot of time with the 8250U in the past, so it will be good to see how it compares to the Core i7-8550U found in upper tier configurations.
Like most of Intel's 8th-gen Kaby Lake Refresh line, the 8250U features four cores and eight threads constrained to, typically, a 15W TDP. While manufacturers can choose a different TDP configuration, the Gram 13 sits at the default 15W. These four cores have a base clock of 1.6 GHz and a boost of 3.4 GHz no matter the core usage. This in contrast to the 8550U that features a slightly higher 1.8 GHz base clock, but a boost that varies from 3.7 GHz all core, to 4.0 GHz in single and dual-core workloads. It's quite clear looking just at these specs that the 8550U holds a decent clock speed advantage in short single-core tasks.
The other main difference is in cache, where the 8250U features 6MB instead of 8MB like with the Core i7 range. The integrated GPU is still Intel's UHD 620 with 24 execution units, and a clock speed of 1100 MHz, just 50 MHz lower than the Core i7s.
So how does the Core i5-8250U differ from the Core i7-8550U, and is it worth paying the extra money to get the Core i7 model? Well let's take a look at the performance difference first.
Looking at 16 different productivity benchmarks, the i5-8250U is, on average, 15 percent slower than the Core i7-8550U, in this case the 15W configuration found in the Razer Blade Stealth. In some tests like Excel and Premiere, the deficit is as large as 26 percent, in other tests like PCMark, that difference is a single digit percentage. For those that prefer percentage gains, the 8550U is 19 percent faster than the 8250U on average, though again there is a variance among test lengths and core utilization.
Right now, the price difference between the Core i5 and Core i7 models of the LG Gram 13 is $150, or 14 percent more for the Core i7 model. Considering you get 19 percent more performance on average, that sounds like a good deal.
Core i5-8250U model we reviewed provides a handy 22 percent average performance upgrade on the Core i5-7200U, though that gain can be as high as 72 percent in heavily multi-threaded workloads. Compared to a Core i7-7500U, you'll get about 18 percent more performance, though again that's higher in multithreaded tasks.
As for the 8550U variant? Well we didn't test that model specifically, but we do know the 8550U is approximately 34 percent faster than the i7-7500U on average, with gains closer to the 50 percent mark in all-core workloads. Either way you look at it, the Core i7-8550U or the Core i5-8250U will provide a ton more power than 7th-generation or older CPUs.
Unfortunately there doesn't appear to be a configuration that delivers more than 8GB of RAM or more than a 256GB SSD. Bizarrely, you can only get 16GB of RAM and a 512GB SSD out of the box with the 15-inch model; both the 14-inch and 13-inch units are left out.
However, the 13-inch Core i7 model does come with 8GB of soldered RAM and a free DIMM slot, making a 16GB dual-channel configuration possible if you are willing to upgrade the laptop yourself. The Core i5 model, like the one we have to review, has 4GB soldered and another 4GB in that DIMM slot, so a nice 16GB configuration is a bit harder. Luckily, you can upgrade the SSD with all units.