user18506: Bitcoin's blocksize limit is currently 1MB. It seems as if Namecoin would have to be bigger due to it proving 512 bytes of storage with a name update, but it also has slower average block times (about 20 minutes according to BitInfoCharts). 
Does Namecoin also have block size limit? What size is it?

user18196: Namecoin has not strayed from Bitcoin in this parameter, it is still set at a 1 MB block size limit. You can find it in main.h:
/** The maximum allowed size for a serialized block, in bytes (network rule) */
static const unsigned int MAX_BLOCK_SIZE = 1000000;


18506: <p>Bitcoin's blocksize limit is currently 1MB. It seems as if Namecoin would have to be bigger due to it proving 512 bytes of storage with a name update, but it also has slower average block times (about 20 minutes according to <a href="https://bitinfocharts.com/namecoin/" rel="nofollow">BitInfoCharts</a>). </p>

<p>Does Namecoin also have block size limit? What size is it?</p>
 18196: <p>Namecoin has not strayed from Bitcoin in this parameter, it is still set at a 1 MB block size limit. You can find it in <a href="https://github.com/namecoin/namecoin/blob/namecoinq/src/main.h#L42-L43" rel="nofollow">main.h</a>:</p>

<pre><code>/** The maximum allowed size for a serialized block, in bytes (network rule) */
static const unsigned int MAX_BLOCK_SIZE = 1000000;
</code></pre>
