Neither
A single speedtest from an unknown point on the the OP's network isn't representative of max internet speed. Speedtest is rather conservative by design and by default
Both Steam and Origin are rather inaccurate.
Origin uses compression and estimates based of percentage of final install size downloaded over time. In other words from one moment to the next it guesses how fast it is downloading based on percentage complete.
Steam is all over the board. Sometimes they only display the initial game size but download far more. The download speed isn't a real measurement of current rate, rather it is a delayed estimate of a snapshot of the game download progress that the client grabs repeatedly. Their speeds sometimes look slower because the patches, etc. aren't included in the displayed rate so the speed will go up and down. It's similar to how Origin estimates but Steam looks at new data every second or so.
Neither is correct nor accurate. Origin is actually more consistent, whereas Steam is actually closer to real data rates, but highly unreliable because you don't know how big the game will be until it is finished downloading and the speeds fluctuate so much.
In theory, Origin should be faster. Steam uses peer technology to reguest data integrity and sends requests for the existence of files before they are sent so it can slow it down. Does that factor in? I don't know