CPU and memory relationship....

Can someone explain how (or if) having more memory has an effect on the CPU. I've currently got 512 MB of DDR SDRAM, and am thinking of upgrading by adding another 512. Would this benefit the CPU, and could I expect to see a fairly dramatic decrease in CPU usage by doing this....or would the effect on the CPU be minimal (or even non-existent)?

 

it affects your programs if you use a lot of heavy software like rendering, gaming, burning,... ...

best way to have 2*512mb. but the more important thing imho is to have memory with tight timings...so everything goes faster.

with amd64 timings are less important cause amd64 has a builtin memorycontroller with high speeds...if you have an Intel best to have tight timings like 2-2-2-5 (tightest at the moment) so you won't have any bottlenecks. These are a little more expensive to buy but I prefer to have fast memory then 2*1024mb of slow memory.

Just my two cents.

it depends...if you like to overclock you should get some with tight timings, running Intel -> tight timings = better.
having 2*512mb is always better.

cheers

I hope I made myself clear, cause memory is often the part that gets cut on when purchasing a new setup......

another thing you should consider is dual channel. having dual channel (means 2*256mb or 2*512mb or ...) will increase memorybandwidth of 50% in most cases. Hyperthreading (if you're using Intel) will benefit a lot from dual channel.
that's the best argument I can give you: dual channel and the fact that you can use three/four programs on the same time easily.

Opt.

 

I agree with the dual channel HT setup, it is what I run.

It should also cut down on your virtual memory page file usage. You will have to change that setting however if you add another stick of 512.

 

However, even without tweaking, if you run any memory intensive programs, then adding more memory will increase the speed of your computer.

 

OK, I hear what all of you are saying about speed, but what is the overall effect on the processor? I've got the Intel 4 with HT technology (which I understand is to allow for multi-tasking of sorts), and often times when I open Task Manager to have a look, one of the processors is maxed out while the other is practically idle, and TM reads the CPU usage as around "50% CPU usage". This is usually during an AV, AT or AS scan of some sort, but not always....and it's practically always one that with heavy usage while the other with very little to nothing. Anyway, I'm curious if adding more memory will lessen the burden on the CPU, and would allow the overall usage (and especially for the primary one) to be lowered (basically function without consuming so many resources).......

 

nope, the amount of memory has no direct effect on cpu performance. but like other people said, if u run a lot of programs having more memory can definitely help.

 

Thanks for the reply, WSFUSER.

So if additional memory has no affect, then what could help lower the CPU usage (besides just not running certain apps in real-time). The CPU currently "spikes" every 10-15 seconds or so, but does the Task Manager measure real-time CPU usage, or is there any delay (in other words, when it spikes on the TM screen, is that real-time usage)?

 

the best is to disable all the processes you don't need in your services panel.

like time, automatic updates, remote registry, dns and ipsec,... that helps my computer in realtime too.

what processes are causing the spikes?

 

That's a good question, Infinity. That's why I asked if Task Manger displays the spikes in real-time, or if there is any delay. I've tried disabling a few apps that run from start up in real time - one at a time - to see if I could determine which one that is causing the spikes....but even then, the processes that I have enabled from start up are ones that I would like to keep active. That's why I was looking for an alternative to lower CPU useage, within disabling what I've currently got (which is fairly minimum, IMO).

 

you can choose columns in your taskmanager (I am at work and to be complete it takes too long and the admin will notice, not a lie but you can choose which columns)
take the column with virtual memory, private memory and you'll see in realtime which services are causing the spikes. it isn't necessary to address this to a program...cause not all programs run as a service.

good luck.

 

Adding memory will not change the CPU usage behavior you see, this 50% CPU usage is pretty normal on HT enabled machines (it was designed to work this way) when performing CPU intensive tasks. Since the "other" processor idles the system should be responsive i.e. you should be able to continue to use the system normally.

"Many resources" is a relative term, the system manages the processor time assigned to the different tasks and if there is enough of this resource it will assign all of it if a is task requesting it. Some application vendors specifically advertise with "low resource usage" or "low impact on system performance" but what they basically do is, to assign a lower priority to their processes or let the threads sleep for some time (some milliseconds are enough). Since the Task Manager display is not real time this will result in lower overall CPU usage values displayed and the system may get other tasks done during this idle time, on HT machines this usually has no effect though.

 

Basically, adding more RAM will increase the performance of your PC because you will have less accesses to the Disk (Virtual Memory), and access to an item on Disk is much more slower than access to an item on RAM...

The same apply's to the Cache and RAM, but to add more Cache you have to buy another CPU...

So, if you can, upgrade your system with more RAM...

 

If you take a good memory module like Corsair XMS XL (2-2-2-5), this latency is much faster then the latency of the cpu cache of prescott

but cache is nice, and can speed things up...when overclocking

 

In order to keep my warranty in tact, I had to purchase Dell Memory (Dell PC). I already had 512 MB, and I just purchased another 512. I'm curious if anyone has added 512 MB of memory to an already existing 512 along with a Pentium 4 processor with HT technology, and noticed a substantial improvement (in speed, responsiveness, etc.). Will it prove to be worth it?

 

Yes and no.

Yes if you play games, surf the Net for long periods of time, or do lots of video encoding/decoding.

As far as resposiveness is concerned, not too much, but you can make out the slight difference.....

 

Thanks Firecat. I intend to add Microsoft Office, and I've heard it's a memory hog...that's why I'm adding the additional 512. I forgot to mention that the CPU is 3 GHz (not that it means a whole lot). 3 GHz and 1 G of Ram should be enough to work, play and surf, shouldn't it?

 

I'm using a 2.4 Celeron with 512 MB with Windows 2000 Professional, Firefox and Office 2003. I leave it on whole day, open and close dozens of firefox tabs, open and close various Word and Excel documents and relax playing Return to Castle Wolfenstein without closing any program and at the same time listenening to MP3's on the background. I never noticed any slowdown. Right now I still have 300 MB available. I see no need to increase my 512 to 1 GB. At work I have a Terminal Server with only 1 GB and 30 simultaneous users running Word 2000

 

I have just about the same type of PC (but mine is an AMD) and everything's butter smooth.

@diginsight: For an example, Texture-heavy games like Doom 3 will benefit from 1GB of RAM, especially if the graphics card memory is less than 128MB.

 

I understand, my trainee is addicted to playing World of Warcraft and complains it doesn't run without 1 GB I gave up after upgrading to an ATI 8500 for Half Life and RtCW, because after 10 years my gaming funds were depleted

Here lies Earl E Adaptor
One upgrade too many
Died without a penny
- Rich Tennant