Is it necessary that i full format all partitions first?
Depends on what you're trying to accomplish.
A Windows full format
reads and verifies all sectors on the drive before setting up the file system structures. It does
not overwrite all sectors or erase them. If it finds a sector it can't read, it maps it out as a bad sector.
A quick format just sets up the file system structures, it doesn't read & verify anything.
I'm of the philosophy that on a brand new drive, a full format is not necessary. The drive was already verified at the factory, so barring any problems in shipping, it has no bad sectors on it.
On a drive that you're reformatting that's been in use for a while, you may want to scan it for bad sectors just for peace of mind. However, there are better programs to check the drive's health than the Windows full format if that's what you're after. Manufacturer's utilities like Western Digital's Data LifeGuard Tools, Seagate's SeaTools, Maxtor's Powermax, etc., or 3rd-party hard drive analysis tools like SpinRite or OnTrack Data Advisor are all better at verifying your hard drive than the Windows full format.
On a drive that you need to erase for security purposes, to get rid of a boot-sector virus, remove a problem MBR, etc. the Windows full format won't do it. In this case you need a hard drive eraser like Active@ KillDisk or Darik's Boot and Nuke.
Because on new drives I don't see a need to full format, and on drives where the health needs to be verified I use a dedicated hard drive analysis program, and on drives that need to be erased require a dedicated program, I therefore never use the Windows full format for anything.