GFXBench GL and the results were between 20 - 40 fps on the tests done,
That does sound like a really horrible result...
There are Intel integrated graphics cards in that list that get >25 FPS. That's around a GTX 460 mobile.
Is your "NVS 3100M" a Quattro? Because that same benchmark shows a Quattro 3100M at 62 FPS. So if that's the case, it's possible your card may be throttling itself from overheating or something.
I don't know. Seems like you need to do some further testing on your system to see if Allegro is actually running slow, or it's just running as fast as can be expected.
A quick benchmark to test is in GPU-Z. It's like the popular CPU-Z program, and it basically tells you a lot of stats about your card as well as whether the clock frequency is dropping. It includes a quick benchmark setting. If say, your card is benching slower than my lowly old chromebook with integrated graphics, then something is definitely wrong.
There ARE rare driver issues with cards that nVidia / et al have fixed in the past where certain programs will run too slow because the card doesn't recognize an app properly so it doesn't leave "low power" state and ramp up to full clock speed. But I thought they had fixed all those issues. (And also, the opposite, where games like Starcraft 2 would actually destroy videocards because the drivers were incorrectly having them run hotter than supposed to back in 2010. Lulz.)
You said you were using Windows 10, but are you using the MOST RECENT drivers FROM NVIDIA, or just stock Windows 10 drivers?