Customers MAY be prepared to wait 8 seconds, but they will NOT rate a site as spiffy and fast if you actually do take 8 seconds.
Naturally a site hosted in the US will be a bit slower than one hosted in Germany (The roundtrip-time increases by about 120-130 milliseconds); this CAN be noitcable, but usually is not. However, if your site is using PHP on Dreamhost, by default, a PHP CGI process is started whereas some other hosts use mod_php. This makes the response-time server-side slow. Even in mod_php-land you can increase the speed by using code compilate caches and optimizers (eAccelerator, etc). Make sure you are doing an apples-to-apples comparison.
(on Dreamhost you can set up PHP to run as a FastCGI process, which can tremendously speed up average response times).
If you are looking to transfer bigger files, the server is not the only thing to be concerned about -- you may have to increase receiving TCP buffer sizes (since the bandwidth-delay product will kick you in the butt on transatlantic links), otherwise you won't be getting more than 350-600kbyte/s on a single TCP connection, maximum.
Finally ... If you care about instant responses to your customers, either host your site close to them network-wise, or employ mirroring and replication in your primary markets. There are also companies specializing in this kind of acceleration service (Akamai, LL, etc.) who will do a lot of the work for you.