I'm still using a Phenom II X3 720BE as processor.
I've already been thinking about an upgrade to the Intel Core i5-2500K but I'm wondering if this is really necessary.
With my current Gigabyte MA790FXT-UD5P I can overclock up to 3.5Ghz which isn't the maximum that you normally can get with the 720.
I have a CrossFire setup with 2 5850 Xtreme cards and I'm thinking about installing my Zotac GT430 Zone Edition as Physx card.
But my motherboard only support 2 Graphics Card setup.
That's why I have been thinking about getting a motherboard upgrade 890FX/990FX.
Is the 990FX really worth it?
Also the price for a Crosshair IV Extreme 890FX is really good at the moment.
Is it still interesting to buy a 890FX/990FX motherboard?
For my opinion, you would be throwing good money after bad. Even with a slightly better overclock, your CPU might match a core i3-2100 in performance. You would likely gain only a few FPS overall. You can view this chart to see where you stand currently, at least at stock speed. http://www.tomshardware.com/reviews/gaming-cpu-overcloc...
A better budget upgrade would be the i3-2100 for now, with a modest ASUS or Gigabyte z68 tri-card motherboard. This will allow a future upgrade path to the i5-2500k, or even one of the new Ivy bridge chips to be released later this year. These motherboards should work for you. http://www.newegg.com/Product/ProductList.aspx?Submit=P...
The best path would be to get a mobo with a PCIe 3.0 slot, but those are kind of pricey right now unless you drop down to say an Asrock board which I do not recommend. You could always save that for a future upgrade for when you get a PCIe 3.0 card.
It is not necessary to replace the 720BE nor get the new motherboard for that matter. The benchmarks pretty much prove out what I said. The i3 system beat out your system ever so slightly, and it was running at stock speed.
My point was, other than the exercise of using the 430 card for Physx, the new motherboard will not get you much, and you will be locked into the AMD upgrade path which will be behind Intel for a good time to come. There is also no guarantee of a higher overclock on your CPU with the new motherboard. You may get a little more, or even a little less. Such is the nature of electronic components.
The Intel upgrade will still allow for the 430 card as Physx, and give you a higher upgrade path. A better bang for your buck if you will.
Of course it is not my money we are spending here. It is ultimately up to you.
edit: A good way to test your upgrade choice would be to take your machine out of SLi temporarily, and pop in the 430 card for Physx to the single 5850. Test it both with and without the 430. This should give you a pretty good idea of what just getting a new motherboard will get you.
Will be interesting to see. Good luck on the Cisco. As someone who used to work in the Telco business for many years, and work with Cisco routers and such, I can tell you that as soon as you learn everything, Cisco will make changes which will put you perpetually behind.
It is part of my education so nothing to do about that.
Also I am having an ambition that is growing little by little.
To be the project manager who communicates with all the departments of IT to give the best solution possible to the users and reports to the IT Manager.
Your system is fine as is. Just get a riser card like this https://www.dealextreme.com/p/pci-e-1x-to-16x-riser-car... and you're good to go. The other upgrades you mentioned would not be cost effective or even noticeable in many situations. BTW, don't worry about bandwidth on the x1 slot I've used an 8800gs physx on x1, x4, and x8 and they perform identically. I recently downgraded it to a gt320, also without penalty (it was cheap, and quieter too).