Where do I see the current, exact DAG size? Is it being tracked on a website somewhere, or is it something I can check on my miner?
If you need DAG size tracker you can visit investoon.com/tools/dag_size there you can see current DAG size and important epochs.
The DAG size is actually calculated by a fixed formula. You can find more details here. The function that does the calculation is:
def get_full_size(block_number): sz = DATASET_BYTES_INIT + DATASET_BYTES_GROWTH * (block_number // EPOCH_LENGTH) sz -= MIX_BYTES while not isprime(sz / MIX_BYTES): sz -= 2 * MIX_BYTES return sz
To make it easier, look for current block number (eg. 121,000), divide it by 30,000 (so it's 4) and look up the size indexed 4 in the
data_sizes array at the end of the link. In our example, it should be 1107293056 bytes.
This size is the DAG size. However if you meant size of the current DAG file, it should have extra 8 bytes (magic number at the beginning of the file which is 8 bytes, documented here). So the DAG file is 1107293056 + 8 = 1107293064 bytes.
@Richard's answer is actually the DAG file size.
You can check it yourself on your miner:
$ ls -l ~/.ethash/ total 1048584 -rw-rw-r-- 1 richard richard 1073739912 Mar 10 20:36 full-R23-0000000000000000 ......
(If you're running a standalone miner, then the file is generated locally, not downloaded from somewhere.)