With 400 bucks I doubt your going to be able to update the cpu/mobo/ram.
Some rendering progs will try to shift the work load to the gpu.
For that type prog a better gpu is a plus.
I don't know what your going to spend for the 660 but a look here might get more bang.
You can try to run parallel cards if you want.....it can be a pita.
I don't look for trouble so I just stick with a single card.
Some folks when they upgrade ram make a hash.
They mix+match sticks which forces the ram to clock down to the slowest stick or they trash the dual channel feature.
I am trying to evaluate what piece of hardware I should upgrade on my main workstation. I was thinking about adding a NVIDIA GTX 660 with the GTS 450 I have, however first wanted to see where my current bottlenecks are before adding another video card. I do not play video games, I spend most of my time on the computer programming and for my business I create virtual tours. I have my operating system on a SSD 840 drive and the rest of my work resides on 4 - 7200rpm SATA drives.
Current System Configuration
Mainboard: BIOSTAR T5XE CFX-SLI
Chipset: Intel P55
Processor: Intel Core i7 870 @ 2933 MHz (max: 3861)
Physical Memory: 20480 MB = 20GB
Video Card: NVIDIA GeForce GTS 450
Network Card: Realtek Semiconductor RTL8168/8111 PCIe Gigabit Ethernet Adapter ( I use BitSync and constantly remote access files off of this computer )
Cooling: Water Cooled CPU and more fans then someone could want for the rest of the hardware.
Average Physical Memory Usage while idling: 19%
Average CPU Usage while idling: 5%
I consistently max out memory and keep CPU usage in the upper 90% if I am either rendering panoramas for virtual tours or using Adobe After Effects or encoding a video or just have a lot of stuff going on with word, browsers, and Lightroom 5.
Maximum Budget: $500 prefer to spend under $400
Would I see a significant improvement increase with a newer motherboard and newer CPU?
Would I be better off adding a GTX 660 graphic card and adding another 2 monitors? - I would only do this if $400 wasn't going to get me a significant performance increase.
Would I just be better off saving my money and maybe adding another solid state for key files I am using in relation to panoramic rendering or video encoding?
Any advice would be greatly appreciated! Thank you for reading this!