Microsoft's new Lumia 950 and Lumia 950 XL are the first phones to run the new Windows 10 software, but neither are the fastest or most powerful handsets on the market.
Both phones still boast an impressive spec, so we decided to pit them against each other in a showdown of speed. This is where we test how well the phones can juggle multiple apps, among other things.
We don't spoil all the results, but when it comes to startup time both handsets are quite slow compared to their rivals. The iPhone 6S came out fastest, followed closely by the Samsung Galaxy S6. Both the Lumia phones did manage to beat out one big competitor, however.
To find out which phone was fastest and whether it's powerful enough for you, watch our speed test video below.