Do I need to Partition the HD?

The reason i make a smaller partition for the OS to sit on is so i can format the OS partition at anytime and reinstall and i still have the other full of data for like a backup purpose.

As for performance you should loose anything either way it still only 1 drive and can read as such

There is also a slight performance boost with a partition. This happens because drives have there fastest transfer rates at the start. And as said above you can reinstall windows(format c  without loosing your files.

I have run partitioned for years(always was windows and files for just that reason. now i just have a drive for each thing   and its still partitioned just for the small bit of extra transfer[and it's in raid too] at the start. and the other one is my temp work/scratch/video editing).

EDIT
also with the fact that its one drive you will not gain any thing while reading from the other partition since the heads have to go back and forth anyway....but when your not there is a slight gain.

I have 4 partitions -
1. O/S and applications - as said above, so I can reinstall OS without affecting data - also this gets fragmented much more than data and makes for a small drive to defrag frequently - defrag this weekly but data can go for months and months
2. General data - also makes it very easy to backup this data by backing up entire partition - very simple - back up to flash drive weekly (or more often if necessary) and monthly to DVD
3. Media - audio and video that normally I have on original disc so no need to backup - or make a disc at time I load it then forget about it
4. Backup for data on #2 - this is just a convenience - I do a real quick backup of the second partition just to protect against data loss or corruption - keeping several weeks copies before deleting - obviously no help against HD failure or viruses

I have found this system very convenient.

The only thing to watch for is someone advising you to put your swap file on the non-windows partition. Some will wrongly suggest that keeping the swap file off of the windows partition will speed up swap file access. This is absolutely wrong as the result is a lot of head trashing during swap access which reduces performance and is harder on the drive. If the swap is put on a different physical HDD then some performance benefits can be realized.

As for partitioning, I am an advocator of the two partition system. For the same reason as some have stated. If Windows get's trashed, or mobo switch, or whatever other reason you can think of for a Windows re-install, you have all your files (or can move) to the second partition and wipe the first clean.

I put my swap file on a separate small partition that is almost entirely filled up with the swap file (remainder is empty space coz otherwise windows complains about low disc space). It has no direct performance benefit as stated above, however it prevents the file from being fragmented because no other files are ever written to that section of the drive. Therefore you don't lose performance over time as the page file remains unfragmented, whereas on a partition like C: it will have data constantly being written to the same area, and it will end up in bits all over that partition.

Thank you all for the responses. Seems the best results woudl eb to make a two partition drive with the OS on one and the rest of my apps on the other.

Another question. How much room do I need to set aside for Windows Vista? 50gb? 100gb?

id say 50gb ... i think it requires 40gb but then allowing for a few proggies and swap file etc. 50 should be a nice fit

Yeah. 50gb seems a good number, says it needs at least 15gb so, I over shoot that and install the other hardware's software on that drive and my games and apps on the 200gb side.

Should work real nice.

Thanks.

2 partitions for me...
50gb for OS/apps
the rest is for data.

defragging the OS partition becomes much easier  

Yeah...that seems to be the way to go. Looking forward to building this system...parts should start coming tomorrow.

@ rockyjohn - good point. forgot how fragmented things got when recording to c:

That's why I have drive D: for a sawp file and E: for everything else.

I use drives(physical not partitions with the exception to c: and h: they are one 500gig raid0 volume) like folders.

c: windows & apps
d: doc's
e: video's after compressed to XviD/DivX
f: backups for files(and virus scans) when i fix computers
g: currently a back-up location against miss saves to files
h: the second have of the raid volume that makes c: and h: and i use it for any high bandwidth files video editing mostly
Also one external backup that contains everything on d: and e:

I certainly agree that the main advantage of disk partitioning is to reload the OS. What I usually do is to install OS and all the necessary applications (MS Office, etc), then use Drive Image to copy the whole drive to the other partition.

As for the faster transfer rate at the beginning of the drive, I would think that since OS is the first software you will install, the OS will be, by default, located in the beginning of the drive.