How fast is 5G? We put the next generation of mobile internet to the test

Key Points
  • Major carriers have been switching on their 5G networks around the world, while a few phones have arrived that support those services.
  • CNBC had the chance to test out two 5G smartphones in London to find out just how fast the next generation of mobile internet really is.
  • Vodafone and EE's networks can achieve pretty fast download speeds, but results were mixed and depended on location and time of day.

We are all being told that 5G, the next generation of mobile internet, will be much faster and provide more capacity than current 4G networks.

Major carriers have been gradually switching on their networks around the world, whether that's in the U.S., South Korea, Australia or the U.K. As of last Friday, you can add China to that list too.

Some 5G-capable phones have already arrived on the market, like the Samsung Galaxy S10 5G and the Oppo Reno 5G.

CNBC had the chance to test out both phones with two separate network providers in Britain to find out just how fast 5G really is.

Speedy downloads

Using EE's 5G network in London to download a season of "Breaking Bad" on Netflix.
Ryan Browne | CNBC

When it came to downloading TV shows, movies, and mobile games, 5G definitely demonstrated a marked improvement on 4G.

I was able to download an entire season of "Breaking Bad" on Netflix in about a minute and a half with 5G. It took me much longer — more than 20 minutes — to do the same on a 4G phone.

Using EE's 5G network in London to download a season of "Breaking Bad" on Netflix.
Ryan Browne | CNBC

I was also able to download the mobile version of "PlayerUnknown's Battlegrounds" in just over 3 minutes using a 5G phone. By contrast, it took nearly 17 minutes to install the game with a 4G device.

That's a staggering reduction in time and something many people could probably appreciate when embarking on a long commute or looking for something to watch (or play, if you're downloading a non-multiplayer game) to pass the time on a plane journey.

Playing PUBG over 5G was also a really smooth experience. I was able to jump into a match fairly quickly and couldn't detect any lag while playing.

Playing "PlayerUnknown's Battlegrounds" on a Samsung Galaxy S10 5G smartphone with Vodafone's 5G network.
Ryan Browne | CNBC

Meanwhile, streaming was also pretty seamless. I browsed through a few 4K videos on YouTube and, when opening them and jumping from one part of the clip to another, didn't encounter any noticeable delay time.

Playing a 4K YouTube video on the Samsung Galaxy S10 5G smartphone with Vodafone's 5G network.
Ryan Browne | CNBC

It's fast — but patchy

When you're in a good spot, 5G is really fast. But you'll often need to be near a mast from one of the network operators to enjoy those optimum speeds.

Testing a 4G smartphone (left) and a 5G handset (right) side by side in Hatton Garden, London.
Ryan Browne | CNBC

I tested out Vodafone and EE's networks in London and found that both can achieve super-fast download speeds, although results were mixed and it really seemed to depend on location and time of day.

Late in the afternoon, I gave Vodafone's network a whirl on the Samsung Galaxy S10 5G, trying out a speed test in Hatton Garden, London's iconic jewelry quarter, which the company said was an ideal location for testing.

Doing a speed test on a Samsung Galaxy S10 5G smartphone with Vodafone's 5G network.
Ryan Browne | CNBC

I managed to get download speeds of almost 200 megabits per second (Mbps), which is way higher than I would normally get on a 4G device. Vodafone claims the network can max out at speeds of around 1 gigabit per second (Gbps), but I wasn't able to get anything close to that.

The best speed registered with either of the 5G devices was 500 Mbps, which was achieved on the +Oppo Reno 5G using EE's network. That's over 10 times higher than the average 30 Mbps download speed on today's 4G phones. It's worth adding that this result came from a different speed-testing app.

Testing out internet speeds on an Oppo Reno 5G smartphone with EE's network.
Ryan Browne | CNBC

But it did end up feeling like a bit of a scavenger hunt eventually, having to walk long distances just to find decent 5G coverage. Often I would lose access to 5G data, with a 4G icon appearing in the top-left corner in its place.

That seems to be a running theme across many of the next-gen networks at the moment, with reviewers in the U.S. and South Korea reporting similar problems.

One of the best speeds Vodafone's 5G network produced was actually back at CNBC's London HQ — at 6:48 in the morning. I managed to get download speeds in excess of 250 Mbps and upload speeds of more than 90 Mbps (compare that with the 60 Mbps download speed and 40 Mbps upload speed I got at the same time on a 4G device).

At CNBC's HQ in London, Vodafone's 5G network managed download speeds of more than 250 Mpbs.
Ryan Browne | CNBC

Speaking of upload speeds, both 5G devices at times managed to achieve impressive rates — 90 Mbps was the top upload speed I got, and that's much higher than the average 10 Mbps on 4G. Other times they scored speeds in line with what 4G handsets are already capable of, if not a little bit higher.

Early days

While 5G proved to be significantly faster than 4G, it's clear the actual rollout of the technology is still in the early days.

This is something even the big carriers admit. In the U.K., they're currently focused on starting with the busiest areas of major cities before expanding out into other regions. U.S. network operators have opted for a similar model, with Verizon and AT&T offering services limited to a number of cities.

Their argument for why you should buy a 5G phone now is because it gives you early access to faster wireless internet that only a handful of people are currently using. And once more people start buying 5G plans, the networks will, in theory, have the capacity to support a larger number of people anyway.

But there are only a handful of devices being sold that actually support 5G at the moment — others include Chinese models like the Huawei Mate 20 X and the Xiaomi Mi Mix 3. We're not expecting Apple to release a 5G variant of the iPhone until next year.

So while it's certainly fast, most users probably won't find much need for a 5G device at the moment; 4G already addresses more general needs like browsing the internet and messaging friends. And it's been shown consumers aren't as willing as they once were to upgrade, as new flagships offer only minor updates to their predecessors.