What does a gaming machine need in terms of Hard Drive

The only real improvement would be a good SSD, since those read very fast and their latency is superior to HDDs, which seems to be the most important for HDD performance in games.

After loading however, a HDD/SSD should not affect the framerate you are getting, so games won't run faster but they will load faster.

And ssd just arn't praticle for gaming.. Unless you're rich.. Thing of the average size game anymore 6-10gb, 128gb cost's what around 300ish..

I got an ssd, I use it mainly for my os, and very few games.. Mainly just ones with lot's of loading. I love it, but if you don't have money to blow wait..

I saved up, and had a set limit when I built my computer which is the only reason I got one. It would've been the first thing to drop if my price was above my budget.

I saw load times improve to a noticeable degree when i upgraded to a WD velociraptor a couple weeks ago

As fast a CPU and graphics as you can afford, and at least 3-4GB of usable memory.

Seriously. While faster disk xfer rates and lower seek times are always better, the question is: At what cost, and would that money be better spent elsewhere?

First question: What are your metrics? FPS? Load/startup time? Synthetic xfer-rate and seek-time benchmark results? ...? Second question: What is your budget? Third question: What existing hardware do you have to work with?

I don't think you're missing anything... as usual, it depends; there are a lot of tradeoffs and there is no single correct answer. That applies to any application or system, not just games.

thnx jsrt, that is what I was thinking,

I have enough money to get what I want, but what do I want lol, I just like good FPS, I have a 250 gig Hitachi drive 7200 rpm Sata2

I am asking because I think I am going to rebuild my system get a new i7 chip and a new vid card so why not a new HD, but I will stick with the one I got if it is fine, no reason to make un-needed contributions to the economy lol