[Freewill1]

Hi all,
I'm new to CFD-Online and have been lurking around here and learning. I'm a student working on geodynamics and dealing with numerical modeling problems like mantle convection, plates collision/subduction, etc.

Here is an typical 2-D case I from paper[1], which is to evaluate the burial and exhumation processes of deep rocks in Alpine-type orogens. To do this, a specialised FEM code named SOPALE-Nested is used. The features is listed as following:

(1) the thermal–mechanical creeping (stokes) flows at the crust or mantle scale is solved;

(2) model materials deform by frictional-plastic (brittle) or power-law viscous (ductile) flow that includes respective strainsoftening/strain-weakening mechanisms;

(3) as for the scale of the model, the domain is 2000×660 km with resolution of 1×1 km.

Here is several figures and animations of the model setups and results:





animation 1: here

animation 2: here


A important thing I learned is that a bandwidth between CPU and RAM really matters for CFD application, and as many people suggested, the newst chip i7-4790K($294.29 on Amazon) has only 2 memory channels but the i7-4820k($319.99 on Amazon) has four and performs better. For me, due to limited budget, I can only afford a system less than $2000.

So I have a question of what kind of system do you think I should buy to meet the need? Many thanks for suggestions of what to buy: CPU/RAM/motherboard/graphic card/...
or do you think a HP Z420 with intel xeon E3 CPU will be good choice?

Best,
Freewill

References:
[1] Butler, J.P., Beaumont, C. and Jamieson, R.A., 2013. The Alps 1: A working geodynamic model for burial and exhumation of (ultra)high-pressure rocks in Alpine-type orogens. Earth and Planetary Science Letters, 377–378(0): 114-131.

[flotus1]

With a budget of $2000 you might even consider the new Haswell-E processors like I7-5820K or 5930K. They also have 4 memory channels and support DDR4 ram.

Edit:
An even better solution in terms of memory bandwidth and cost efficiency might be a setup with 2 AMD Opteron processors.
This will almost have twice the memory bandwith compared to the Intel system and a much higher number of cores.
The performance per core will be lower than for the Intel system, but If you are not limited in the number of cores you can use for your simulation it is worth considering.