Maximum PC

Hey all, I'm using HandBrake (latest version) and reading a file from one of my hard drives (F:). Thing is, I'm seeing Handbrake only using about 50% of my i7 920 OC'd to 3.66GHz w/HT on. Recently I had to reinstall Windows on my SSD (C:). Before the re-install, Handbrake would use 100% of all 4 Cores/8 Threads.

Any thoughts? The settings are exactly the same as I had before the reinstall. I thought it may be something to do with my HDD (I'm using a 1TB Samsung F3) so I tried the same thing with the files on my SSD and it's still using only between 40/60%.

Thanks all.

Settings:

Preset: High Profile
Container: MP4
Source: 720x480
Anamorphic: Loose
Modulus: 16

Video Codec: H.264
Framerate: Same as Source
Constant Quality: 20

Advanced: b-adapt=2:rc-lookahead=50

I may have missed it, but what is the physical F:/ drive? I could go on and on with speculation, but really need to know what F:/ is to keep that speculation short. And is F:/ an old drive you use to use and just referring to it with a new drive? That's not clear.

Right now, I have to assume this is a Frankenstein and ponder many directions to go with this.

F: is a Samsung Spinpoint F3 1TB that I keep my main programs/swap file/games on. My drives are set up as follows:

C: - OCZ Vertex 120GB (Windows)
D: - Optical Drive 1
E: - Optical Drive 2
F: - Samsung F3 (Main Programs)
G: - WD Caviar 2TB (Primary Storage)

Handbrake reads from one folder on F: and writes to another, also on F: normally. To see if something was up with the drive, I instead had it read the file (after copying) on C: and write to C:. There was no % useage increase even when using the SSD (C:) instead of the mechanical HDD (F:), which makes me lean toward it not being a SATA bandwidth issue.