That's what you want. BD High-def and H.264 in general is one of most compute-intensive operations that your computer can do. Its a massive amount of frame-processing, compression, and disk access. Basically, everything.

The fact the software is using all available resources to get the job done quick is a good thing.

CUDA reduces my processing time about 35%, but I haven't done a ton of testing with/without GPU encoding enabled. I'm sure it varies on the power of your video card, too.

I have a AMD quad processor and it runs consistently about 90%, so I probably could have used a bit more powerful GPU and it would fully load the processor (and get done quicker). Win8 64-bit Pro Retail
Intel i7-4770
16GB DDR3 1600 8-8-8-24
MSI Z87-G45 Motherboard
ASUS GTX 660 Direct CU II OC 2GB GPU
1 TB RAID 1 (mirrored) Drive Array
Several scratch drives for video, TMP, pagefile.

Ontheweb
This is my computer specs
Phenom BE 950
4 GB RAM DDR 3
GTS 250 1 GB G,card
Barracuda 7200 RPM HDD

The PC is overclocked to 3535 CPU and RAM 1616 Mhz PC specs :
OS Windows 10.0 Pro
MB - AS rock Z77 extreme 11
Intel 3770K @ 4.0 Ghz OC
Gskill 32 GB RAM 1800 Mhz
6 TB HDD, SSD bootable
nVidia ASUS GTX 660 Ti
BenQ 22" LCD monitor 1920x1080

Quote: Ontheweb
This is my computer specs
Phenom BE 950
4 GB RAM DDR 3
GTS 250 1 GB G,card
Barracuda 7200 RPM HDD

The PC is overclocked to 3535 CPU and RAM 1616 Mhz

Almost the same as me, except I have the 940 processor. Same video card except mine's 512K. I do have a 4-drive RAID 0 array that's pretty fast. Win8 64-bit Pro Retail
Intel i7-4770
16GB DDR3 1600 8-8-8-24
MSI Z87-G45 Motherboard
ASUS GTX 660 Direct CU II OC 2GB GPU
1 TB RAID 1 (mirrored) Drive Array
Several scratch drives for video, TMP, pagefile.

I think when rendering PD will take as much resource as possible. However, other parts of PD are limited as to the resource used. For example, I think , PDHanumanSvr.exe is limited to 50% of the available (not total) CPU resource.

That's a particularly useless piece of information that was passed on to me when trying to bottom out loading/processing times for .mp4 files.

Cheers
Adrian Life is really simple, but we insist on making it complicated. (see below)
Confucius
AMD Phenom IIX6 1055T, win10, 5 internal drives, 7 usb drives, struggling power supply.

I have a Q9300 and a 9500GT video card and if I create a mp4 file from a single clip in the timeline I've gotten about 40% CPU usage and 50% drop in encoding time. If I also insert a clip in the PIP track as well my CPU usage goes up to near 100%. In my case I was using mts files from my Canon HG20 camera.

Edit:

I just tried another file. This file is 1 hour and 10 minutes (about 13 GBs) which was previously produced with mpeg2 BD profile. I dropped it into the timeline and selected mp4 with CUDA. My CPU usage is 25-30% and the rendering time is 2 hrs and 45 minutes. Q9300 2.5 GHz
4 GB Ram
Nvidia 9800 GT