RAM usage?

[cl@ude]

Let's say say you have 1gig of RAM on your computer. Two 512MB sticks. But under Task Manager > Peformance, it never gets past 512 MB of usage. Is one of the RAM sticks just sitting there going to waste without ever being used? Or is it being used? Does the computer use both sticks having both of them sharing the memory used by the OS???? Or is the memory slot more like a storage for the non-used memory stick...?

[foxyloxley]

What OS are you using ?
Some only work up to 512 MB. [I think ? ]
You SHOULD be seeing the total amount of RAM, as that is what is available.

[nihil]

Yes,

I have a number of machines with 1Gb or more............if I only use them for office applications, surfing the net, a bit of music...........the odd game and tend to single task rather than multitask, then I strongly suspect that one or more of the sticks just is not being used.

I had a look the other day...............XP can get up to 320Mb in virtually dormant state, and get just over 512Mb. Win2000 goes to about 190Mb, and I don't think that it will go over 512 with what I do.

Now, if you run desktop publishing, CAD, image editing, or high tech games you can certainly go to 1Gb or more.

Hope that helps


EDIT: Foxy~, if he has "performance" in task manager he must be using an NT based OS, which will support at least 4Gb (I think)

[sec_ware]

Hi

task manager infos

In the task manager, you most likely have quite a few numbers.
While "Physical memory.Total" shows you the total amount of
memory you have installed (should be 1047276), the usage bar
just tell you how much actually is used (allocated) by running processes,
as nicely elaborated by nihil

performance

Most likely, recent (BI?)OSs automatically make use of both memory bars.
If they sit on different banks (which is usually the case ? ), the OS
can increase the performance of your system, because it hides the
latency[1a,1b] of the memory bars. As a side-remark: This was one of the main
reasons, why Cray computers were so expensive - and fast - they had
up to 1024 memory banks. And another side-remark: People tried to build
vector-computers with a number of banks, which is prime - to hide latency
optimally, because everything is addressed with base 2[2]. Aah, never mind


Cheers.

[1a] http://www.devhardware.com/c/a/Memor...emory-Latency/
[1b] http://www.pcstats.com/articleview.c...eid=873&page=1
[2] http://www.cs.swan.ac.uk/~csneal/HPM/memory.html

[nihil]

I think that sec_ware has it right.

Old 9x OSes tended to run on machines with memory banks that required you to put the largest modules in the lower bank numbers (usually closest to the processor)...........sure they would work if you did not, but they worked better if you did?

I think that modern OSes are probably using all installed memory in a more efficient way?

I have had a brief discussion with sec_ware and I believe that I have an empirical method of testing this

Naturally, I regard the concept to be his intellectual property, and will merely supply him with my test results (I have too many fingers to be a typist, and do not have the legs to be a secretary ..........copyright...........SHUT UP...........or I will have to have my friend Benedict XVI deal with you))

I guess we have a project timescale of around 4 weeks, plus sec's writing up time?

Cheers

[cl@ude]

I don't think you really understood my question. Lets say i have Win XP with 1gig of RAM, two sticks of 512MB. 2 sticks of 512MB = 1GIG of RAM. Now, if your system doesnt go over 512MB which in this example equals only 1 stick of RAM being used, because it didn't go over 512MB. Now if the RAM usage goes over 512MB, the OS is now forced to use the other stick becaue it went over 512MB so now 2 sticks are being used...

So the main question, since the OS is not using more than 512MB of RAM which in this example 512MB is one stick, and that leaves one stick of 512MB that is unused. So since the OS is not using more than 512MB, is the other stick not being used??? Or does it somehow share the memory to 2 sticks, lets say 200MB are being used by the OS, that would mean 100MB on each RAM stick.

If the memory is not shard by the 2 sticks and the memory does no exceed 512MB (1 stick) is the other memory stick going to waste??????
I hope that was clear enough...

[nihil]

Hi,

I would say that with WinXP if you have 2 x 512Mb sticks of RAM and never peak above 512Mb then one stick of RAM might as well be in your desk drawer.

All the memory pundits advise that you get the largest sticks that your motherboard will support. If your system were capable of using both sticks concurrently, they would suggest 2 x 256Mb for a 512Mb configuration.

I cannot comment on dual channel RAM, but if you have RAMBUS RDRAM (pretty rare these days) you have to use matched pairs of RIMMS, so you may have some redundancy forced upon you.

I must admit that I am not up to date with the very latest motherboard and RAM technology, but what I have said should apply to most desktop/laptop machines that you will encounter today.

Hope that helps.

I would suggest that you run your machine at peak usage (for whatever you do) for a while then run the resource manager............your peak RAM usage should be somewhere on the bottom left?

Provided you have more than that you will be OK................otherwise you will be using virtual memory that is not as efficient.

[The Duck]

Well, did you check to see if your OS even recognizes the other stick?

In case you don't know how:

Go to control panel, click System, and click the general tab, look at the bottom and it should tell you your processor speed and how much ram you have... If it says you only have 512 then it's not recognizing your other stick...