How does fio handle --size= and --offset in conjuction with --numjobs

I want to repeatedly read (sequentially) a span of 1GB, and I want to have, say, 4 threads (i.e. numjobs=4) to increase the produced throughput.

I'd like the 4 threads not to read from the same 1GB segment, but to each have it's own segment to read from. For one thread, if I understood right, I can use --size=1G with --io_size=200G to get fio to continue reading for a long while.

I thought of using --numjobs=4 and --offset_increment=2G but I'm not sure how fio will handle the --size parameter: will each thread read from its calculated offset (offset+offset_increment up to 1GB more than its first offset as I hope? I don't see how fio will know how to do this, and I'm wondering whether what I want is even possible...

Thanks!