First machine for simulations
 

This is my first post on this forum so hello to everyone :)

I'm not really specialist in cfd. I only did half year basic ansys CFX course, and half year Fluent curse during studies. But I'm really into it and i would like to get to know it better when i have more time.

Right now I'm trying to build kind of a workstation so I could use it for my master thesis (not sure about translation).
My experience tells me that you know best what you need when you really need it, so probably I'll know my needs after I start doing simulations. But...

I found this guy on internet selling xeon e5-4640 with motherboard Asrock X79 extreme4-M for only 2000 PLN, wich is about 500 euro.

I find it to be great occasion for me to buy cheap and good hardware to begin with.

Before i found this i was about to buy i7-3770K, so what should I do?
Also i read that I dont need ECC ram, but could someone confirm this so i could be sure.

Thanks for help in advance and also sorry for any mistakes (english is not my native language).

What program will you be using?
Will you be running parallel cores? If so how many?

I'll be using Code Saturne as a solver. Also I want to try OpenFoam but i hear that it's complicated.
I would like to run computations on as many cores as possible to speed things up. But because of lack of experience I dont know yet how many I'll be able to use. Therefore I'm asking if I'll be able to utilize e5-4640 which is 8 cores with 2,4 GHz freq. Or should I go with more like gaming build with 3770K - 4 cores and 3,5 GHz freq. Price is the same (probably guy is selling engineering samples).

Well we don't know how many cores you will be running. If one, two, or three, then I'd say the 3770K might be faster. If more than that then the XEON may be faster.

You have 4 memory channels with the XEON, and only 2 with the 3770K. This may make a difference if the code you use is limited by memory bandwidth.

But it really depends on the code and your parallel capability. I don't know anything about Saturne, perhaps you should find out about parallel licensing for that code.

I agree with you. As for licensing, Code Saturne is open source, and hence it should'nt be a problem.

The 3770k is $332 the E5-4640 is set up to run in quad processor machine and is $2725 so getting them at the same price seems strange, anyways I'm guessing the xeon will do better as it would has a higher theoretical performance (Gflops), and has 20 Mb of l3 cache vs 8 for the I7 as well as quad channel memory instead of dual. The extra memory and cache should help the code scale well.

I bought xeon. Just like i thought it is ES processor, but seller is kinda keeping it a secret. He sold it with motherboard and installed cooler so I couldn't see writings on heatsink. It's sealed and i can't detach it or I'll lose warranty, which is 2 years by the way so I think its a good deal. Cooler he gave me is AVC Napoleon, not the best choice I think.
I also bought used quadro fx 4600 but it turned out to be bad idea. It uses a lot of power and came with broken capacitor. Seller repaired it but it looks like he didnt have a lot of soldering practice. Now I have problems on boot because sometimes card is not giving signal to monitor.
Thank you for all answers.