Just wondering if anyone would be able to recommend a particular PC spec, inparticular specific makes/models of components.

Intel Core 2 Duo E6400 2.13Ghz, 1066Mhz FSB, 2MB L2 cache 256MB nVidia Quadro FX3450 graphics card 4GB RAM. XP Professional SP2 250GB hard drive

CD-adapco ok'ed this but were required to remain impartial, hence could not recommend any particular makes/models.

Couple of points: - I know that a lot of people would recommend going away from Windows but this is not an option. - Budget is limited. The spec will not be able to get much higher than this, I am wondering about recommended makes (i.e. for graphics card).

Thanks.

Alex

Do you need that expensive a graphics card ? I have an nvidia 7900GT on a linux box and it works just fine for Prostar and ensight (which is graphically more intensive than Prostar). I don't have enough experience with CCM+ but it will almost certainly be OK as well. This card is about $700 cheaper.

Perhaps if you are running a CAD package then the certified drivers make it worth it.

Otherwise for the solver the fastest CPU makes sense, you can get a 6700 for about $150 more than the 6400 and it clocks at 2.66 GHz. That should get you about 20% more speed.

One thing to note is that if you run 2 processor parallel to use the CPU and memory then don't expect to do anything else on the machine. Windows tasking basically dies under the load of running a CFD code.

Finally if you are using this in an office environment is noise. My HP at home is quiet when doing normal office type things but when running CFD dual core (it has an AMD X2) it howls annoyingly.

The problem is how to find out how noisy a PC is under load, as typically you can't test this easily. One possibility if you can at least get access to one is to listen to it on startup, typically fans run at max speed initially until they are slowed down by the temperature controller. However it is difficult to extrapolate that noise to how you/your colleagues feel after after half an hour next to a noisy computer.

As for a brand the gaming machines (i.e. Dell XPS) make some sense as they are usually designed for full load work and therefore are probably specced to last under these conditions (and hopefully have quieter fans too !).

Good luck.

I will start off saying I know nothing about CCM+, I use Star version 3.26. My WINDOWS machine is a DELL XPS GEN5 and I have built 3 million (trim) cell model and it executes fine. I also use Peo/E on it. The noise isn't a problem, but the heat is.

I have 4 gig memory but can not do two phase flow problems on the 2.3 million cell model because I become memory limited. My plan is to add a second 250 gig hard drive and set the machine up as a dual boot system of LINUX and WINDOWS. Because XP Pro SP2 is limited to accessing a little over 3 gig of memory (you need the 64 bit version for higher), I am looking at downloading a 64 bit version of LINUX and increasing my memory. I really think LINUX is the way to go.

I had an ADAPCO engineer in my office a couple of months ago. He was using a laptop with XP Pro SP2 and a vertual machine (using VMWARE) that allowed him to switch between WINDOWS and LINUX using a hot key. Microsoft now has a free version of the virtual PC that I may give a try.

Best of luck, Alex.

Tom

Some more comments - usually increasing the amount of cache adds to performance, especially in memory-consuming problems. So you can consider even E6420 with 4Mb of cache.

On the graphics card comment....STAR-CCM+ is heavier on graphics than STAR-CD so you will want something fairly reasonable, if you are using other apps like CAD you will want some decent graphics too. The quadro you have should do the job nicely, On the memory front 4GB should be ok for the time being, remember if you use 32bit windows you will only be able to address 2gb per cpu, you also have to remember that M$ windows runs loads of useless background apps that eat memory for no good reason (windows really isn't designed for engineering analysis) so make sure that you optimise the OS and get rid of all the garbage that bill gates sees fit to stick in! You may want to consider windows 64 as STAR-CCM+ is ported to that

We are currently looking into upgrading the pc's at my work. We have limitations such as: only Dell machines, only some kind of windows - 64 bit will be our choice.

We are going for a Dell 490 because it has a high FSB of 1333MHz and it has 8 ram slots(8Mb is our initial choice). We are going to use Xeon dual pus with 3,0 GHz and buy two of these machines. We want to be able to run 4 in parallel which is what we can do with 2 Dual cpu's.

We are currently using Star-CD v3.26/4.0 and Star-CCM+. We also get a little tied up on the grapics card, since it is wo expensive (Dell upgrade from 128Mb to 256 and 512 cost approx 500$ and 1500$). We have decided to go with the 128Mb graphics and then upgrade one of the machines if we observe that it is required eventually.

I suggest that you do the same and save money on the graphics. Use some more on the CPU. I think that if you are limited by budget, then buy something that can be upgraded later. IT at my work suggest to buy (upgrade if possible) new 'CFD' pc's every 3'rd year and let the pc's be the second best. It is stupid to buy the newest and most expensive when you can get that in 6 months for 1/3 of the initial price.

Have luck and please let us know what the result is and what you will go for..

BR Kasper Skriver

Thanks for all the comments - all really useful.

I will consider the virtual PC option to allow both Linux and Windows to run on one machine, but I do not know much about Linux so will have to do some research.

Going to look at these options, in order of preference:

1 - Virtual PC (Windows/Linux). Problems here are lack of Linux knowledge, extra cost of two OS and flipping back and forth with SolidWorks. Am I correct in assuming the SW will not run in a Linux environment?

2 - Windows 64. Problems are cost and compatability with other software. I have been told that 32bit programs generally run fine on Windows 64 - is this correct?

3 - 'Normal' Windows XP. Problems include lack of RAM - CD-adapco suggested a rule of thumb of 0.5GB per million cells.

I will also spec a slighlty lower graphics card and upgrade the processor slightly.

Any more comments about the above three options would be greatly appreciated.

Thanks,

Alex

Would someone be able to recommend a distribution of Linux that is best suited to CCM+?

Thanks

Alex

Answer to my last question is that Suse Enterprise and Red Hat Enterprise are officially supported.

For information, the final system spec is as follows:

Intel Core2 Duo E6700 CPU (2.67Ghz, 4MB Cache) 2x 250GB hard drive (to keep XP and Linux seperate) 4GB RAM Windows XP Pro 32bit nVidia Quadro FX3500 graphics card

Will be configured for dual boot with XP and Linux.

I will provide details about performance once I have used it with CCM+.

[doug]

Alex - Did you ever compare the performance of CCM+ on Windows and Linux? I'm considering switching to a Linux machine if it will speed up computation.

[ggulgulia]

hey alex

I have been using STAR CCM+ for a year and a half. I would suggest you go with a 8 Gb of RAM and could compromise on the graphics card.

If you plan to run simulations with a mesh count of around a million then you'd need atleast 4 gb of RAM for mesh generation and another 2-3 gb for running the simulation