I was testing out some things today, mainly about the newly discovered Vampire+Necromage synergy bonus that gives most of your spells pretty much a 25% magnitude and 50% duration boost.

I ran the tests with the High Elf's racial: Highborn. The describtion says "Power causes a tenfold increase in regeneration rate."

Here are my test results:

player.getav MagickaRate: 3 (probably referring to the 3% of maximum each second outside combat)
With Highborn powerer it becomes: 34.25
After removing my vampire undead status: 28.00

I also tested with adding/removing the Apprentice stone (100% regen) and removed my Recovery perks in restoration which adds 50% regen. None of them have any influence on the number you got from the console command I used. Clearly the highborn power is modified by the Vampire/Necromage synergy.

My question however is: how does the code work for those 34.25 and 28.00 numbers?
I'm just trying to figure out the logic behind getting such strange values. 28 + 25% would result in 35, not 34.25. And how do you get to 28 with a tenfold increase from 3 anyway?

Tenfold just means a lot not literally 10x in Skyrim

About the 34.25: Earlier in your post you already said that you get a 25% magnitude increase for spells which results in: 25 * 1.25 = 31.25
Now add 3 base and there you go

Now something different: Being a vampire means being undead. You are the target for the Highborn ability which is incorrectly set as a Restoration spell (something that is fixed by tsssss and will probably fixed in a future patch/ unofficial patch). Therefore you trigger the Necromage effect on yourself.

Oh something I forgot: there are 2 different "stats" for magicka rate:
MagickaRate and MagickaRateMult

MagickaRate is the base magicka regen and Highborn directly modifies this value while stuff like enchantments modify MagickaRateMult

The formula for Magickaregeneration should be something like this:
Magicka per second= Max Magicka * MagickaRate * MagickaRateMult
= Max Magicka * [( 3 + effectmod) / 100] * ( 1 + effectmod /100)

rofl...
Ok so the Highborn power simply adds a flat 25 instead of actually modifying something...

Thanks alot, curiosity problem solved.