I have a Samsung 830 SSD in my notebook connected to a SATA interface. This is a rather old HP notebook nc8430 which means SATA is SATA I and not II or even III that disk supports. But SATA I still supports speeds up to 150MB/s so I expected at least double values as per image below.

CrystalDiskMark shows rather slow performance:

I've been using this SSD for over a year now and I would like to know what to do to make it blazingly fast as other reports say it should be?

Edit

As suggested I'm adding AS SSD screenshot of the test.

And Samsung Magician's benchmark which is likely biased...