Ram upgrade inlinux
 

Hi,

I have upgraded the RAM from 2GB to 8GB in my Linux machine and swap space is around 4GB.. still my system performance is slow.. please help me how can i increase my system performance .....

I use CentOS5...

You must be doing some serious graphic stuff to need to ramp up to that much memory . . .

- try Reducing the /swap partition to below 1Gb - say 512Mb
as with that much memory - it's way too big.

Increasing RAM will help IF you were using all the avaible RAM. It wont speed up your system at all if you werent using most/all your RAM before the upgrade. To speed up the system when you werent/arent using all your RAM, a faster CPU and/or HDD would be the way to go.

You might be able to remove some unused or uneeded modules/software to increase preformance as well.

I'd assume with CentOS its being used as a server of some sort. Having a large swap partition will NOT impact performance.

What are you experiencing as performing slowly? Games, graphics window managers? Because there are some things that in my experience dont move quickly no matter how much hardware you throw at them. KDE for instance.

Make sure you have the correct graphics drivers installed.

Run "top" or other task monitor as root. Find out which process is wasting your RAM or resources. Once you know what is wrong, you will have a base to fix it.

Try grabbing the KDE System Monitor (my favorite sysmonitor) and check for memory/CPU usage. If nothing shows up there you could try running a performance benchmark and see if HD read/write speed has anything to do with it.

I wonder why nobody asks what exactly is the purpose of this machine? Is it a desktop machine, a server, a numbercruncher, ... .
Also, how did you determine that your RAM is the bottleneck slowing down the machine?

With that much RAM, the swap file probably won't be used at all. Run df and see if it is, I'll bet there's almost no usage. Just what aspect of the system is "slow"? The GUI? Response time? Is the hard disk busy all the time? Have you tried a different desktop to see if there's a difference? Your system should not be "slow". I've not found any recent version of Linux to be "slow" on any reasonable hardware, with KDE or not. Try turning off effects and see what happens.

My machine is not slow by any means (AMD Phenom II X 4 955), but I recently increased my RAM from 4 GB to 8 GB and saw absolutely NO gain in speed on my machine using Linux. Now my Windows 7 partition is a different story. I saw some gain there because Windows is a resource hog. My Solus OS runs about 335MB at idle while Windows runs around 1600MB. I think you will have to look elsewhere in your machine to find what is running slow. Like in my case it's probably your hard drive. I want to go SSD soon.

Free memory is wasted memory. It's an old wive's tale that a system should have lots of "free" memory. If it's free, it isn't doing anything. I have 8 gigs and almost all of it is used at the moment.

[dean@localhost ~]$ free
total used free shared buffers cached
Mem: 8181888 8007288 174600 0 88164 6058108
-/+ buffers/cache: 1861016 6320872
Swap: 4400124 24 4400100
[dean@localhost ~]$

Your swap space should always be double the size of your RAM. Having 8 GB of RAM should have 16 GB of swap space allocated. Change the swap and check for the status.

Thanks
Buy lace

Absolute nonsense. With 8GB of RAM there is not only no need for a swap file, it will never be used. You don't need any swap space for typical desktop use unless you have less than perhaps 2GB of RAM. Some distros don't even activate swap space any more. That's not his problem.

I hate to quote to emphasise but this is the question.

True.

Not really true. While it may not be needed it will nonetheless be used. Running out of physical RAM is not the only case where swap is used. Even on my main machine with 16GB of RAM swap is sometimes used for swapping out stale memory to make more place for cache. This is a standard behavior on Linux.

True. But I didn't expect insight to this problem from a spambot anyways.

True, but seeing that the OP checked in to LQ yesterday but still gave no answer to any question here I doubt that this thread is still relevant. Would be nice from the OP to posts if there is still a problem or if that issue was solved.