The Dell Latitude 13 7390 2-in-1 Review

Wireless

Dell has outfitted the Latitude 7390 with the Intel Dual Band Wireless-AC 8265 wireless adapter, which we’ve found to be the best adapter of the most recent generation, with great performance, and fantastic reliability. We’re still waiting to see the latest 9000 series arrive in notebooks, with wider channel support, but regardless, the 8265 has been a great NIC.

Once again, the performance is very strong on this 2x2:2 network adapter, almost competing with the 3x3 solutions in actual performance. It’s never the wrong decision to have this NIC in a notebook.

Audio

As with most laptops this size, sound quality is not a real possibility. Peak volume is pretty good at about 82 dB(A), but the frequency response is very bland, with it only really producing mid-range tones. That’s enough for a conference call, but that’s about it.

Webcam

Since this is a business machine, it’s likely going to partake in video conference calls, and it would have been nice to see Dell put a better webcam in. The webcam is only a 720p model, and doesn’t do well in low to medium light. On a premium model like this, a 1080p webcam is more in-line with expectations.

Thermals and Noise

The Core i7-8650U CPU is a 15-Watt TDP, but under burst loads it can easily draw double its TDP, so cooling is important. In a small laptop, it’s even more difficult to ensure good performance without making a device that sounds like a jet plane.

Dell offers several settings for thermal management as well, with the default being the “Optimized” mode, where it balances performance, noise, and device temperature, but you can also choose Cool, if you want to keep the temps down, or Quiet if you don’t want the fans to kick in unless necessary. For those that need the most out of the device, there’s also an Ultra Performance mode where the fan speeds are ramped up quicker to ensure the device doesn’t throttle excessively.

Every CPU throttles under load, otherwise the TDP would be infinite, so the goal of any U series laptop is to be able to get rid of 15 Watts of heat. To see how Dell did, we ran our x264 benchmark for 30 minutes straight in the Ultra Performance mode.

The laptop initially bursts to about 28 W of draw for the first short bit, but then quickly drops down to closer to 20 Watts of draw for over the first five minutes. After that, the temperatures have ramped up to over 90°C so the CPU finally gets put down to the 15 W, where the temperatures are kept in check and the device keeps the heat in line. The CPU frequency has to drop to do this, of course, but once it gets to steady-state of 15-Watts of draw, it doesn’t throttle any further.

Since the CPU does drop in frequency over the course of this load, it likely looks like the device is throttling over time, but that’s only the case after it drops from the roughly 20-Watts it’s drawing for the first 700 seconds or so.

The laptop does keep the CPU in check, but how about the chassis? To check that, we use the FLIR One.

As you can see, temperatures on the chassis are good with the laptop under load. The keyboard deck can get close to 40°C, but the keys themselves don’t feel very warm, and the wrist rest area is nice and cool.

In any of the other fan modes, the CPU is going to be thermally throttled a bit quicker, but if you do need sustained performance, the Dell does provide it.

The downside to this is noise though, which peaks at 45.3 dB(A) measured 1” from the trackpad. It’s not the quietest laptop around, but under load, that’s expected. At idle, the laptop will turn off the fans altogether, although in the default Optimized mode, the fans do spin up far too often, creating excessive noise even if the laptop is only under a slight load, which can be annoying. In the Quiet mode, it’s much easier to live with.

Software

Dell has done a great job keeping the extra software to a minimum, which will make IT people happy. The only software that’s pre-installed is a couple of Dell utilities, which are genuinely useful. The Power Manager we’ve already looked at, and the other is the Dell SupportAssist, where you can get hardware tested, and update drivers, or reach out to Dell for assistance.

It’s a nice light touch to the software, while still providing some value with their own offerings.