Why do certain programs make my PC almost unusable during high CPU usage?

I do a lot of 3d modeling, rendering, baking, etc. A lot of this results in 100% cpu usage during certain operations. For instance, in Maya, when I render an image, my CPU goes up to almost 100%. This turns my cursor into a slideshow that progressively gets worse the longer the render takes.

Sometimes, it'll slow down so much that it locks up my PC and I have to hard reboot (although this is rare).

The way I combat this is by setting the CPU priority to Idle and also reducing the CPU affinity to 2 of my 4 cores.

This allows me to continue using my cursor and do things in other programs, however this causes the render to take longer.

This is not limited to Maya either. When I bake images in Topogun, it results in 100% cpu usage and again, I must lower priority and reduce affinity to ensure my PC remains usable.

Otherwise, the cursor turns into a slideshow and the whole PC becomes unusable. This is quite frustrating and doesn't make any sense to me.

Does anyone know why this happens, or how to deal with this besides lowering CPU priority / Affinity. Any help would be appreciated.

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Running or Installed Software: I do have a ton of running processes, but a lot of it seems to be idle and use zero CPU.

AVG (Disabled until I need it)
Dropbox (Usually idle)
Everything (Instant search program, doesn't cache)
Minibin (Sys Tray icon for recycle bin)
Greenshot (Screenshot utility. Does nothing while idle)
Spotify (Listening to music. Last I checked, doesn't utilize a lot of CPU)
Steam (Self explanatory)
Teamspeak (Does occasionally use some CPU, but nothing to be worried about)
Listary (assists typing for navigation in file explorer windows)
Chrome Web Browser (Always running - I try not to have too many extensions)
Realtek (Systray Icon)
Catalyst Control Panel (Systray Icon)
Process Hacker (Task Manager Alternative)
Bill2's process Manager (I use this to auto set affinity/priority on programs so that when a program reaches a severely high CPU usage, it automatically sets priority to idle to ensure my PC remains usable)
Content Manager Assistant (For my Playstation Vita - Pretty much does nothing while idle)
Display Fusion (Adds multimonitor things)
Pokki (Start Menu Alternative)
StartKiller (Removes Start Menu icon)
SuperF4 (adds hotkey to terminate foreground window)
LastpassBrocker.exe (I gotta have my lastpass)
PnkBstrA.exe (not sure why punkbuster feels the need to be running constantly)
Spybot Search and Destroy (I should probably disable this)
SteelseriesEngine.exe (for my mouse drivers)
XboxStat.exe (for my xbox controller)
Dragon (Like chrome, but safer)

All in all I have 126 running processes, but a lot of those come from google chrome and dragon because they feel the need to run like, 20-30 processes because each individual tab counts as a process.... I guess it's fine, but it inflates my running process count and makes it look like I have a crap ton of stuff running.



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My system specs are as follows:

Windows 7 Pro 64bit
CPU: Intel Core i7-870 Lynnfield 2.93GHz LGA 1156 95W Processor BX80605I7870
GPU: MSI R5850 Twin Frozr II Radeon HD 5850 (Cypress Pro) 1GB 256-Bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX ...
RAM: Kingston Hyper X Genesis 16GB Kit (4x4GB Modules) 2133MHz DDR3 Non-ECC CL11 DIMM XMP Desktop Memory
MOBO: MSI P55-CD53 LGA 1156 Intel P55 ATX Intel Motherboard
HD: OCZ Agility 3 AGT3-25SAT3-120G 2.5" 120GB SATA III MLC Internal Solid State Drive (SSD)
HD: Various Seagate Physical drives