if u are using VISTA give atleast 30 GB to drive ...vista itself takes about 15GB....atleast thats what i m planning to do ....cos other updates(SP1) and softwares do take a lot of space ..u can also go for 40 GB or 50 GB ....
@imgame he has brought 500GB HDD. Not 160GB That U R Telling For Going For 40-50GB.
As I Also Use 3D's Max And Maya It Takes A Lot Of Space For Rendering. So I Think U Should Keep About 4 Partitions. All Should Be 120GB's 120*4 = 480GB And LeftOver Give To C:/. But Dont Do Too Many Partitions.
I think u should go for at least 6 to 7 partitions. Allocate 40-50Gb for C: and make the last two partions with the highest space. I will make ur drives performance good. If u have less partitions, then defragmentation will occur. And the drive will have to perform more read and write operations for a single partition, so go in for at least 6 partitions. Also, set the SWAP file on the last partition. It will give increased performance. Set it to 1.5Gb to 2GB.
Same as ingame2 and ubersoldat, I would suggest you to keep 2 primary partitions of 50-60GB each, install OS on the C drive and install your programs on the other drive rest around. make rest as extended partition (and logical drives in that extended partition). and then divide them. Keep your logical partitions of bigger size, though whenever you try to defrag them it will take hell a lot time but atleast it would be good and not get slowed due to less space.
Try keeping your drive where you install OS and programs separate from your bulk data like movies games n docs.