Can I scale up from 1 to 2 nodes with mixed CPU?
 

I want to see how scaling up from 1 to 2 nodes improves the calculation speed on CFX. I already have 2500K/Z68 system. Is it ok to buy the FX-3850 system to connect to my old one with GigE?

You could certainly do that, but I'd probably just get another 2500k instead, especially if you're paying a per-CPU license. That AMD chip isn't really any faster than the i5, but it uses a lot more power and twice as many licenses. Plus I always prefer to keep things homogeneous, even if it isn't explicitly required.

According to cpubenchmark.net, the Intel i5-4570 is a bit faster than the Intel i5-2500K and costs roughly the same as an AMD FX-8530. Better still, the i5-4570 consumes less electricity than either one of the other two.

As for CPU performance index, the FX-8350 (index of 9047) has roughly 2000 performance points (whatever that is :rolleyes:) more than the i5-4570 (index of 7080), but this means using the 8 cores.

As for using a Gigabit Ethernet, it's a bit unbalanced, since it'll be 8 vs 4 cores, unless you only use 4 cores on the AMD... but for that, probably best to go with the i5-4570.