[Dorit]

Hi everyone,


I'm currently looking into buying a new workstation to run Fluent 12 and 14 on it. I would appreciate if someone could give me some information or suggestions on what kind of workstations to buy to reduce the computational time of Fluent.
Here is a rough outline of the simulations I’m planning to do:
- - Hybrid mesh of 5 – 7 million cells used in the sliding mesh configuration in Fluent
- - Transient simulation that is required to run for up to 30 seconds flow time with time steps of approximately 0.001 – 0.0005 seconds
- - Coupled solver, 2nd order discretisation scheme (spatial & temporal)
- Mainly 2 equation turbulence models, i.e. k-ɛ and k-ω models
- - Computational time of up to a month which cannot be interrupted due to the nature of the transient study
- - Parallel computing with Fluent


For choosing a suitable processor that reduces the computational time, is it more important to invest in a better technology (AMD, Intel Core or Intel Xenon) or should I increase the number of cores (quad, six or eight)? For a given number of cores is it better to have all of the cores in one CPU (a six or eight core machine) or to have a dual CPU system (two Quadro core)?
Is the speed of the CPU or the cache of a CPU more critical for a fast simulation? So, between a CPU of 3.3GHz and 15MB of cache or a CPU of 3.6GHz and 10MB of cache, which one is more favourable?
To what degree is the simulation performance dictated by the RAM? Is an increase of the RAM always associated with an increase in the simulation speed or is there a maximum amount of RAM after which the CPU power will limit the simulation speed? Is a 16GB RAM memory sufficient for what I'm trying to do or should I go for 32GB RAM? Is there a difference whether I get ECC or non-ECC RAM for Fluent? Can an ECC RAM reduce the number of crashes and potential simulation errors, such as AMG solver divergences?


I know it's a lot of questions that I've just posted but it'd be great if someone could give me some suggestions on a few of the points I've mentioned.



Thanks,
Dorit