The reason I didn't code SETI Driver to do multiple, simultaneous transmits is that I discovered (by losing WUs during development) that the SETI Data servers would lose WUs when you do this. There needs to be some time between the start of each transmit. I coded in a 30 second timer to force a reasonable, but small delay. On a slow link, this timer expires before the transmit finishes, but you will see it on a LAN. If this timer expires while the transmitting WU is still in progress, SETI Driver changes that process to "High" priority. This doesn't interfere with other processes in the system because the client spends most of it's time waiting for data and spends very little CPU time. This setting allows the transmit to occur at "network" speed, regardless of the priority setting of the SETI Client (or clients) that are actually processing a WU.
As Poof said, SETI Driver will start another WU while it's transmitting. What she didn't say was that on "Auto Transmit", SETI Driver starts the next WU before starting the transmit.
Mike.