you will NOT notice a difference on first generation games if its DESIGNED for the 360
"Xb360info.com: For those gamers with the Core system, how will the absence of a hard drive impact on the game performance and/or features (loading times or other)?
Codemasters: We have to assume that a lot of gamers won’t have the HD. That way we’re designing a fast loading experience for everyone from day one. Any HD caching benefits from there are icing on the cake."
"Xb360info.com: What can be done in games for the Xbox 360 that was not technically possible with Xbox games?
Codemasters: As I said above, the graphics are an obvious improvement. However another big win for me is in the increased RAM size over current gen. It means we can start to see large persistent worlds on a console. That is, when you knock over an object, there will be enough RAM to keep in memory the new position and orientation of it. When you go back to the same object later, it should still be in the same position, rather than resetting.
The same goes for AI – the game should be able to control and track many more bots and the like. That was really difficult with the old gen consoles – especially for cross-platform based games. "
"Xb360info.com: Are any of your games impacted if Xbox Live users do not have a hard drive in their Xbox 360 console, such as loading times, responsiveness, or things you can do (such as map editors etc)?
Codemasters: Not at present. As new games evolve, you never know, but there are no issues we can see at the moment. Remember the memory units are much bigger which would help with such situations. "
AGAIN if the game was DESIGNED for the 360 then things such as caching are not neccessary they can be streamed directly from the disc due to tis high transfer rate and low seek times to the extremely fast and vast amount of ram which can store more then enough data making the HDD for use in gameplay situations USELESS, UNLESS the game was ORIGINALLY designed around a 5x DVD rom and 64MB of RAM. Please read this in depth.
http://www.xb360info.com/xbox/interviews/146First gen games likely yes. But as the games get more complex all that roomy memory and blazing DVD speed will seem like less and less. I can remember when they doubled the size of floppies to 1.44MB, everyone I knew said it was impossible to fill that space up...
Remember games comming out now are only scratching what the 360 could do, when things get more complex every bit would have helped. They alude to it in the last answer "Not at present".