[Willo]

Hi there,

Can someone provide a minimum or recommended specification for running OpenFOAM on a standalone machine, in terms of;
- processor (size, speed, no core)
- memory
- hard drive
- Ubuntu - version ?
- etc

I have a limited budget so please consider value for money.

Thanks,
Geoff

[wyldckat]

Greetings Geoff and welcome to the forum!

I would say that the minimum requirement is to have a working 32 or 64bit x86 computer In other words, to have a normal PC would be enough!

The real question is what do you really want to do with the computer and OpenFOAM? The reason is simple:

• A - You can balance things to have a machine that can deal with really big cases, even if it then is slow as a turtle to do anything else;
• or B - have a machine that is fast and uses smaller cases.

For A, you could aim for a machine with 16 or even 32GB and a slower CPU. For B, you could aim for a machine with 4-8GB and a faster CPU. The rule of thumb I usually use with OpenFOAM is that 1 million cells require 1GB of RAM for the mesh alone.

As for hard-drives, if the budget is limited, stick with the normal 1TB hard-drives and stay away from SSD flash disks.

As for graphics card, it also depends on the sizes of the meshes you're going to use. For now, you can stick with a machine that uses an integrated graphics card, but you should plan for an upgrade in about 2-6 months for adding a good graphics card to it, which is when you possibly will need to do heavy post-processing.

As for Ubuntu... it's hard to say. Ubuntu 12.04 was released a few days ago, which should become the new standard for "stable long term Ubuntu installation", specially if you're buying a really new machine. But since 12.04 is very new, OpenFOAM hasn't been thoroughly tested with it. So, if you're buying the machine this week, you better install 11.10 for now. But in a months time, 12.04 should be a safe bet.

The last issue is: how tight is the budget? I ask this because technically it's possible to use OpenFOAM with a 250-300€ machine...

Best regards,
Bruno

[Willo]

Thanks Bruno,

I am planning for this machine to be dedicated to OpenFOAM usage and my budget is about Euro1,200 (USD1,600). What is key;
- processor
- RAM
- harddrive
Thanks,
Geoff

[wyldckat]

Hi Geoff,

Unless there is a big difference in prices from where I am to where you are, then for 1200€ you shouldn't have to worry much about what to buy! It can't buy you a workstation, but it can buy you a pretty decent PC! Of course it also depends if 1200€ is for the whole machine (tower+monitor+keyboard+mouse) or just the the tower.

A very quick window shopping gave me this and it's only an idea:

• Intel Core i7-3770 3.4GHz (3.9GHz Turbo) 8MB BOX - € 272.9
• Asus P8Z77-M PRO Intel Z77 SK1155 - € 132.9
• Corsair Vengeance 4x4096MB (16GB) DDR3 1600Mhz CAS9 1.5V - € 102.9
• Western Digital Caviar Green 3TB 64MB SATAIII (6GB/s) - € 159.9
• OCZ Vertex 3 - SSD 2.5 SATA III 120GB - € 153.9
• Asus GeForce GTX560 DirectCU 1024MB GDDR5 PCI-E - € 176.9
• Total: € 999.4

For having 32GB of RAM, about an extra 100€ would be necessary, but I'm not certain if the 8GB modules have already hit the commodity market...

The SSD would help give you a faster base for the operating system and running cases, but it isn't crucial. The 3TB hard-drive can be used as storage space but it should work pretty well as system hard-drive as well.
Another detail is the i7-3770 CPU, which is the non-overclockable CPU. It's cheaper than the i7-3770K version, which is overclockable. Basically, overclocking should only be used if you're already familiar with the concept and/or have someone to help you make a good stable overclocked machine.
FYI: "overclocking" means that instead of the CPU running at 3.4GHz, it could be overclocked to perhaps 4.4 or 4.6GHz. But once again, this requires experience on this subject.

Now it's only a matter of playing around with what you really want, but like I said: for 1200€, you shouldn't have to worry too much.


But the best is to contact your local dealer for computers and state that you want a very good and fast CPU, with 16GB or more RAM would be perfect. The list above should be a good base for what you might want.


There is also the possibility of buying an AMD CPU instead of Intel, but I don't know how the real performance is when comparing between two similar machines running OpenFOAM.

Best regards,
Bruno