Hardware question
 

Hi all,

I run fluent 6.1 on a single pentium 4 2.4GHz processor with 512MB RAM. Anyone know if a supplement of memory (say 512MB) will dramatically improve performances and computing time ?

thanks, John

Re: Hardware question
 

Hello,

Since I've never used Fluent I cannot say for sure, but I don't think an extra 512 MB of RAM would have too much impact on your calculations. The timings of the memory should be more important, but most of all a new processor.

I know this is not the right forum to discuss things like overclocking, but you might get some increased performance with just minor tweaking of the processor and memory.

Finally, if you use 2x256 MB in dual mode then I would say no to an upgrade. If you use 1x512 MB in single mode then it might be worth it anyway (especially if you use win XP).

Regards

Re: Hardware question
 

I think it depends on the size of your fluids problem. If the 512 MB RAM will hold all the arrays and instructions, etc., then adding another 512 MB is like having a 4-car garage for 2 cars.

However, if your problem is big and parts of the arrays, etc. have to be paged to the hard drive, things will slow drastically.

Obviously, a faster processor (if matched to the bus and memory) will help for large or small problems.

Actually the Fluent support folks should be able to help. I'd bet they've heard the question many times.

Re: Hardware question
 

This will depend on the size of the simulation you are running. Normally the operating system and all the applications you are running are stored in the RAM memory. If the size of these applications exceeds the capacity of the RAM memory then your computer will use the hard drive in addition to RAM. Accessing data from the hard disk is much slower than accessing data from RAM so this situation is best avoided.

Your computer currently has 512 Mb RAM - if your OS and (non cfd) applications take say 100 Mb and you run a simulation that requires 250 MB of memory you have 162 Mb free. If you were to add another 512 MB you would have 674 Mb free and would not expect any increase in performance..

If you ran 100 MB (OS + apps)and a cfd job that required 600 Mb of memory on your current set up you system would store 188 Mb of data on the hard disk - if this data was required for your cfd job you would benifit from adding extra RAM and would expect a substantial increase in performance.

You can use windows task manager (in windows) or top (in unix/linux) to see how much memoery you have available)

Also if data is being stored on the hard disk during a simulation it will be easy to spot because the hard disk will be making a grinding noise and the little light on the front of your computer will be flashing away :)

Good luck

Tim.