[Torkad]

Hi all,

Since I cannot use the company's workstation that I'm currently working with for my master thesis anymore, I have decided to spend some money on a well-suited workstation for CFD, considering that my poor old laptop is clearly not enough to run my simulations in a reasonable time. My main problem is that I cannot afford more than about 1300€, so I have to find good price-performance ratio. I know that this is pretty low budget, so I might be able to spend a little bit more, like 100-200 €, if it's worth for the performance.

The case that I'm currently working with is simulation of flow in small GNL tanks with ANSYS Fluent 16, so it's a multiphase problem with phase change modelling. For now, I've been dealing with axisymmetric simulations so I've kept number of cells between 20k-60k, but I'll probably have to move to 3d with around 2-6 million cells in the future. The OS that I use is Windows 7, but I might like to move to Ubuntu in the future in order to work with openFOAM.

I'm a total newbie when it comes to hardware stuff, but based on what I've read in this forum and others I've thought on a build like this one:

CPU: Intel Core i7-6800K 3.4 Ghz (~480€)
Motherboard: Asus X99A (~250€)
GPU: Asus GeForce GTX 960 2GB GDDR5 (~200€)
RAM: 4x G.Skill Ripjaws 4 GB 3200 MHz DDR4 (~110€)
PSU: Fractal Design Edison M 80 Plus Gold 550W (~100€)
CPU Fan: Noctua NH-U9DX i4 (~60€)
SSD: OCZ Trion 150 120GB (~45€)
HDD: Western Digital Purple 1TB 3.5'' RPM 7200 (~52€)
case: Antec Gamers GX505 (~55€)
Total=~1352€

About the CPU, I've been told that for intensive use Xeon processors are better than i7, but based on what I've read here I think I may get way better value for the price with the i7-6800k. One choice for about the same price is the Intel Xeon E5-2620 v4 2.1GHz.

Furthermore, I chose the GTX 960, which seems fine enough for the postprocessing and CAD stuff I'll have to do. Maybe, it would be a better idea to go for a GTX 970 with 4GB, but the price goes up to about 300€, so it gets a little bit out of budget.

The RAM choice was made trying to get the fastest RAM available, since it seems to be one of the most important things to care about when doing cfd. Moreover, I chose 4 sticks since I think it's what I need to properly use the 4 memory channels available for the processor. There are some concerns regarding this choice:

• First, 16 GB total seem to be enough for my purposes, but maybe I should consider spending more to get 32 GB. With my budget limitations, it seems impossible to get 3200 mHz RAM, but I can downgrade to 2133 mhz and get the 32 GB for about 30€ more. Is it really worth it to go for the fastest memory? Maybe I can also just try to stretch the budget to get the 32 gb with the fastest memory.
• Second, having a look in the official Intel webpage, it seems that i7-6800k only supports 2400-2133 ddr4 memory. Should I be concerned about this? I think I've read somewhere that is no problem, but I'm still quite unsure.

As far as I know, it's important to get a good quality PSU. I have no idea about what brands are better, so I just chose one that I saw in another post here. It seems that 550W is enough for the build that I thought about.

As I have said previously, my knowledge about hardware is very limited, so I'll welcome any advice that you can give about the build and what changes can be made to improve it.

Thank you very much

[flotus1]

My first advice when on a tight budget: compare the prices. Some of the price tags you quote are rather high. I don't know where you reside, but in my region this site is pretty helpful: http://geizhals.eu/?m=1

A few hints concerning your setup:
Use a motherboard specifically designed for Broadwell-E CPUs, for example Asus X99-A II.
A GTX 960 should have 4GB of VRAM. In order to stay within the budget you can pick a GTX 750TI 2GB instead. As I mentioned in a similar thread the GTX 970 is neither necessary nor recommended for a CFD workstation.
To save some money on the PSU you can choose this one instead: http://geizhals.de/be-quiet-straight...-a1165594.html
Noctua coolers are great, but this one is too flimsy and too expensive. There are better options when on a tight budget, for example http://geizhals.eu/scythe-fuma-scgm-...loc=uk&hloc=eu
I would recommend an SSD with at least 240GB, there are some for less than 60€.
Same thing applies to the HDD, drives with 2TB offer a much better price/capacity ratio.
A good choice for the case would be the "Nanoxia Deep silence 3". It costs around 70€ but comes equipped with noise insulation and three rather silent fans. If the workstation is placed under your desk this is money well spent.

Xeon Processors are not a good alternative in your price range because of the low clock speed and memory support.
While it is true that the I7-6800k officially supports DDR4-2400, using faster memory is usually no problem. If 4x8GB DDR4-3200 are too expensive you might as well buy slightly slower memory and overclock it manually.