I am currently picking out the pieces to use in a new build. I have choosen the EVGA 780i Mobo. I would like to have a seperate drive for the OS I was thinking Western Digital Raptor 74GB 10,000 RPM 16MB Cache Serial ATA150 and then 1 or 2 more for general use(games,music,files...)and I have been looking at Western Digital Caviar SE16 WD5000AAKS 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s

First off compatability. The Mobo states 6 SATA 3Gb/s and 1 ATA100 2 Dev. Max. The Raptor is a Serial ATA150. That is still compatabile with the SATA 3Gb/s correct?

How many GB's do you guys recommend for an OS?

And lastly RAID configurations, you can call me a NEWBIE when it comes to this. Say if I go with the Raptor and two of the 500GB HD's. What is the best configuration for these three? And I dont want 1 of the 500GB mirroring the other I would like the full 1TB storage. The MoBo states SATA RAID 0/1/0+1/5/JBOD.

Questions, comments, complaints? All are appreciated

Thank you

First off compatibility of the Raptor is fine... SATAI is backwards compatible with SATAII

If you are set on these drives Raptor for OS is a good choice (albeit expensive) its a fast hard drive and 74gb will be more than enough for OS (is use 20gb partitions for XP on my machines).

The 2 other drives... you really only have 2 choices RAID0 or RAID1... since you dont want RAID1 then RAID0 is your only option. This will increase read and write performance (will be faster than the Raptor) however, you have double the chance of loosing your data as if one drive fails you loose the lot.

Read the Wikipedia RAID article here to get more of an idea on raid levels:
http://en.wikipedia.org/wiki/RAID

Personally id go for (depending on your space requirements) 2x 500gb or 750gb drives... set them up as single stand-alones, partiton 1 for a smaller OS and the rest as a lump... this will give you 3 partitions in OS... eg. System, Games and Backup?

If you think you need more space than that i would look into RAID5 as it at least has some redundancy for data. Although you will need 3 disks for this and are probably better off with a dedicated controller.

I could go the way you suggested and use partitoning(although I need to do some research on how to set it up). I know I said beofore that I didnt want to mirror one of the drives but it would be nice to have that extra security incase one of the HD's fail. So would you recommend doing RAID1 over the partioning?

Depends if the data you have is important enough to you to justify it. See personally i was using RAID1 for a while for all my documents that i didnt want to loose should something happen. The only reason i suggested partitioning is so that you can keep your documents on the second partition and if you ever need to re-install windows you just format the first partition and install and all you files will still be on the other. Its easy to setup just have to create a smaller partition when installing windows.