It is probably the domain. Try visiting the subdomain and seeing if Joomla is still slow. Also, I don't see how you can get 1MS ping for Google...
joomla does use a lot of recourses on the server, so there's a good chance that joomla is slow and other software isn't when the server is getting a lot of requests (as in ddos) or when some people make a backup.
Try to install joolma 1.5.10, works fine for me on another host.
hey there, it seems that you are judging the speed by pinging, which is absolutely not correct. When you ping the site it sends the request to the server and then the server returns the reply about its ip.
What exactly you are seeing now is that the site is slow because the server where the site is hosted is slow in response. Its just like that all the machines does not have the same speed so does all the host srever. if the server is slow so the response time to send reply will also be slow, or maybe there is too many requests on the server so it will take more response time which is why you are seeing the delay.
Joomla is pretty fast if used with proper host or you can check with some dedicated host having joomla installation.