How are intrinsic gas and up-front cost related?

[siladu]

https://github.com/ethereum/yellowpaper/blob/f41ec9a6785374c1d9b9e9a064e3ceae1413805a/Paper.tex#L696-L711

We define intrinsic gas $g_0$, the amount of gas this transaction requires to be paid prior to execution

The up-front cost $v_0$ is calculated as:
$v_0 \equiv {T_{\mathrm{g}}} {T_{\mathrm{p}}} + {T_{\mathrm{v}}}$

[siladu]

Answer from @ajsutton:

Intrinsic gas is the minimum cost of the transaction (might be exact cost if it's a transfer).
For contract execution you always pay more since op codes are paid for on top of intrinsic.

Intrinsic gas is the minimum amount the tx bound to use and is a combination of a flat rate (depending on the kind of tx) and the size of the tx's payload.

$G_{\mathrm{transaction}}$ = 21,000 gas, a base cost for every tx
$G_{\mathrm{txcreate}}$ = 32,000 gas, an extra cost for contract creation
$G_{\mathrm{txdatazero}}$ = 4 gas, paid for every zero byte contained in the tx payload (literally, count the number of zeros in the payload)
$G_{\mathrm{txdatanonzero}}$ = 16 gas, paid for every non-zero byte in the tx payload (number of bytes - number of zeros)

It can be seen as pre-execution validation, since we will not execute the tx if the tx gasLimit < intrinsic gas amount:

(i) gasLimit >= intrinsic gas

1. The sender pays for the tx's gas limit ($T_{g}$) @ the gasPrice (the upfront cost)
2. Transaction execution is performed
3. Any unused gas is refunded