Personally I believe that in most applications, good performance is part of a good UX. 8 minutes of load time sounds like quite a lot but then again I don't know what application this is about and what's actually happening in those 8 minutes.
I'd say: If you've got spare time to work, make it quicker. It can never hurt. Then again, optimizing has become one of my hobbies anyway, I just like to knock off a few cycles here and there (I find that weirdly relaxing).
UX-wise the question is actually not whether it's truly fast, but whether it's "reasonably quick". What is reasonable here? If it's a very complex application, users expect it to load up longer. If it's notepad, nobody wants to wait for an hour for it to load. Or think about a 3D graphics engine. Nobody cares whether it runs at 100 or 150fps, as long as it doesn't go below 60 we're all fine.
On a sidenote I want to tell a story. A friend of mine has been hacking away on some Android ROM based on a modified MIUI and he noticed that it takes ages to install. So he had a look at the sources and found out that the original author had quite a weird way of installing stuff. Basically, what he did was copying the same files multiple times and deleting them again. He was just burning cycles. My friend wrote the author an email, asking why he's doing that. The answer was along the lines of "It looks better if it takes longer".
I'd say: If you've got spare time to work, make it quicker. It can never hurt. Then again, optimizing has become one of my hobbies anyway, I just like to knock off a few cycles here and there (I find that weirdly relaxing).
UX-wise the question is actually not whether it's truly fast, but whether it's "reasonably quick". What is reasonable here? If it's a very complex application, users expect it to load up longer. If it's notepad, nobody wants to wait for an hour for it to load. Or think about a 3D graphics engine. Nobody cares whether it runs at 100 or 150fps, as long as it doesn't go below 60 we're all fine.
On a sidenote I want to tell a story. A friend of mine has been hacking away on some Android ROM based on a modified MIUI and he noticed that it takes ages to install. So he had a look at the sources and found out that the original author had quite a weird way of installing stuff. Basically, what he did was copying the same files multiple times and deleting them again. He was just burning cycles. My friend wrote the author an email, asking why he's doing that. The answer was along the lines of "It looks better if it takes longer".