Can't tell if my ISP is throttling my connection or not

[digital10]

When I do a speed test my connection is about 200Mbps as promised but when I download files I get varying speeds

Examples:
1-I downloaded off itunes a 4GB film and all I got was 24-55Mbps.

3-I downloaded iOS update I got speed of
to high 100sMbps but after the 1st GB I dropped to around 24-65Mbps

How can I know if my ISP is throttling or if the company server is purposely limiting download speeds to ease the load? I have been watching speed testers on youtube and they download 10s of GBs off Steam and Playstation servers at 700+Mbps for a lengthy time without issue.

 

[L&LD]

Your actual download speeds depend on the server you're connected to and the load that server has.

If various (different) speed tests indicate full speed, you're most likely getting it.

 

[digital10]

Your actual download speeds depend on the server you're connected to and the load that server has.

If various (different) speed tests indicate full speed, you're most likely getting it.

what if my ISP has an algorithm or rule in place that download speed will decrease to 25% after 1GB of continuous download?

 

[ColinTaylor]

what if my ISP has an algorithm or rule in place that download speed will decrease to 25% after 1GB of continuous download?

There are any number of "what if" scenarios. Ask your ISP what their policy is.