Hi The Dude's teck,
Thanks for getting in touch!
Okay - so you are running 295 MultiPing targets on a Windows 7 machine with 3.12GB of ram. If you are experiencing performance issues then this sounds like you might be about maxed out as far as that hardware goes.
I'd recommend checking out your Resource Monitor in Windows (search for it) and see how the CPU, HDD, and Memory usage is for the MultiPing application. System resource usage is really the main bottleneck for how many targets you can trace to in MultiPing. If you find you're redlining and hitting the maximum amount that the machine can handle I would recommend upgrading to a more capable machine.
If that's not a possibility currently you can always change around some of the Packet Options ("Edit" -> "Options" -> "Packet" ->) to try and optimize things a bit. You can adjust your "Ping Timeout" down from 3000 ms to 1500 ms and set your "Time Interval between pings" lower (1 ms should allow up to 1000 pings per second but this would use a lot of bandwidth and may cause issues). Here is a manual link with more details:http://www.multiping.com/manual/packetoptions.html
You can also adjust your Ping Interval for all targets upwards so that you are sending pings less often. Try playing with some of these settings and see if you can optimize things so that they are more responsive.
Let us know if there are any other questions we can answer for you!