I am a bit confused. My doctor gave me 15mg Oxycodone HCL which from my research is oxycottin? Which from my understanding is the same as percocet, just without the acetaminophen and it's time released. Correct?

Here is where I am really confused, I was originally taking 10/325 oxycodone immediate release tablets... he now gave me the 15's to bump me up because I have been taking the 10/325's for so long for my chronic illness, and my sickness is getting worse causing more pain, but that's besides the point. My question is.. if I am thinking correctly, wouldn't time released be weaker then what I was originally taking? Ill use the number (30 mg) to make the milligrams round out for my "math" to be equal and easier to make sense

So if I took (3) 10/325 immediate release pills. then I would instantly be getting 30mg of oxycodone..right? but now, if I take (2) of these 15mg time released pills, they wont be as strong because they release slowly over a long period of time.. right? Beacuse it would be 30 mg of oxycodone over a period of time instead of being instant... so to get the same effectiveness would I need to crack the 15's in half so they work faster or just the same as taking (3) instant release 10/325's?

Or am I completely wrong?