More RAM?

mi1ez

Splendid
I was just curious, and thinking of upgrading with the current low prices.

I currently run 2Gb of 1066DDR2 RAM in my machine in dual-channel.

I have 32Bit Vista. If I wanted to add more RAM, should I get 2 more dentical sticks, or 2x512Mb with the same timings or 1x1Gb.

I know 32Bit will only address 3.2Gb of it, but I want to keep the dual-channel setup.
Only buying 1Gb would be cheaper, but would the extra RAM be more beneficial than the dual-channelness?
And can I run 3 Gb as a pair of 512Mb and a pair of 1Gb?

Currently I'm thinking to just get 2x1Gb.

Any suggestions?
 

boonality

Distinguished
Mar 8, 2008
1,183
0
19,310
12


And how do you know this? Personally I believe that to be an incorrect statement.

As for your question, if it were me (not knowing your budget), I would just buy a good pair of 2GB sticks for 4GB of memory because it's just downright cheap. You can get a 2GB stick for only a small percentage more than a 1GB stick. if you want to stick with dual channel and upgrade from 2GB of total memory... definately go 2 x 2GB.
 

Scotteq

Splendid
Well... you have a couple options:

(1) 2 more 512 sticks - Make sure you have the same timings/voltages as what you have already. Be aware that you may have some tweaking to do to get all 4 DIMMS running. Possible vDIMM bump, possible FSB voltage bump..

(2) Install 1 1 GB stick - Lose dual channel operation

(3) eBay the RAM you have, buy a pair of 2GB sticks. Keeps Dual Channel, but you won't be able to use half of one stick worth.

I woudl go option 3, since RAM is that cheap. But that's me, so...
 

boonality

Distinguished
Mar 8, 2008
1,183
0
19,310
12


I don't like the sound of this, please explain why half of one stick won't be used?
 

Scotteq

Splendid



In 32 bit Windows operating systems, the total addressable space available is 4GB. If you install a total of 4GB worth of RAM, the system will detect/use/display less than 4GB of total memory because of address space allocation for other critical functions, such as:

- System BIOS (including motherboard, add-on cards, etc..)
- Motherboards resources
- Memory mapped I/O
- Configuration for AGP/PCI-Ex/PCI
- Other memory allocations for PCI devices

Different onboard devices and different add-on cards (devices) will result of different total memory size. e.g. more PCI cards installed will require more memory resources, resulting of less memory free for other uses.

This limitation applies to most chipsets & Windows XP/Vista 32-bit version operating systems. Again, this is a limitation of the Operating System not having enough address space to allocate to the system *and* the RAM. Not allocating address space to devices renders them inoperable. Not allocating addresses to RAM simply results in the unaddressed section not being used in an otherwise fully functional computer. Therefore the OS designers assign RAM last.

We can have long debates about mathematical fundamentals and discussions about why the original Windows designers couldn't allocate the full theoretical max of 36 bits of address space so that users today would be able to use more resource. But at the end of the day, the designers and engineers 'Didn't Then'. So we 'Can't Now'.


If you install a Windows operating system, and if more than 3GB memory is required for your system, then the below conditions must be met:

1. A memory controller which supports memory swap functionality is used. The latest chipsets like Intel 975X, 955X, Nvidia NF4 SLI Intel Edition, Nvidia NF4 SLI X16, AMD K8 and newer architectures can support the memory swap function.

2. Installation of Windows XP Pro X64 Ed. (64-bit), Windows Vista 64, or other OS which can provide more than 4GB worth of address space.



Note: According to the latest Change Log published by Microsoft, Windows Vista 32bit SP1 will display the installed amount of RAM. This is a display change only.
 

dagger

Splendid
Mar 23, 2008
5,624
0
25,780
0
Get another 2gb. Ram is dirt cheap those days anyway. So what if you waste 500mb of ram? And 3.2gb is conservative estimate, you system will likely be able to utilize more, although certainly less than then full 4gb.
 

notherdude

Distinguished
Jul 18, 2006
2,425
0
20,460
204
SCott is correct, of course, should be a sticky

shorty answer: 32 bit MS consumer OS is limited to address 4 gig total memory. Some of that 4 gig total addressing range must be reserved for other devices with memory on them. The limitation is the OS and it's 32 bit limit. Solution is to go to Vista 64 or XP 64.

4 gig - reserved addresses = 3.2 or less, sometimes a little higher, but rare today with big video RAM.

To the OP: get 2 x 1GB identical - gives you maximum mem in DC , the price difference is hardly worth considering and you may decide to upgrade to 64 bit OS at some point soon in which case you will have all 4 gig
 

boonality

Distinguished
Mar 8, 2008
1,183
0
19,310
12
hehe... That article was written well but anyway I'll spill the beans.

The maximum amount of physical memory addressable by 32bit operating systems is 4GB, that's 4096MB.

Now subtract from 4096 your typical 512MB video card and you have 3584. Now subtract from 3584 a rather liberal overexaggeration of all other chipset and sound card memory, we'll use 150MB. That's 3434MB of memory that can still be allocated. Comes out to 3.35GB

That's just an example, but what I'm trying to stress here is that it isn't windows, and it isn't 3.xx amount of memory or anything, it's 4GB of memory but what is constantly missunderstood is that it goes like this

4096 - all mandatorily allocated memory (video card, sound card, other PCI cards, chipsets, etc...) = amount of memory that can still be allocated REGARDLESS of how much RAM is installed in the computer.
 

boonality

Distinguished
Mar 8, 2008
1,183
0
19,310
12
Granted... if you have 2GB of RAM installed, then the equation still starts at 4GB and then you will have more than 2GB that can be allocated hence you will utilize all RAM installed. If you have 4GB installed, then only the amount that can be allocated will be. I should have added that to begin with.
 

dagger

Splendid
Mar 23, 2008
5,624
0
25,780
0



Meh, Having only 3gb utilized out of 4... that's a lot of devices attached. :p
It'll do better than that. 3.2gb is a conservative estimate. Anyway, let's not debate things that don't really matter. Even 3gb should be enough for typical usage, so there'll be little difference.
 

boonality

Distinguished
Mar 8, 2008
1,183
0
19,310
12



Well I just wanted to make sure that the "why" is there correctly. If you have 4GB of memory installed, windows does not just go and utilize 3.21 or 3.5 or whatever, the math behind it may change the OP's decision on which way to go about upgrading.
 

vvhocare5

Distinguished
Mar 5, 2008
768
0
19,060
32
I was faced with the same decision. I had 2x1G sticks of memory and wanted to go to 4G.

The literature I was able to find suggested that the memory can be downgraded in performance (clocks) due to the increased load of 4 sticks of RAM. For best performance always use as few sticks of RAM as possible (Intel website). One of the posters above did mention that you may have to tweak some settings just due to the load. Some motherboards change the command rate from 1T to 2T without your being able to override this setting. It is *supposed* to have a major negative impact on performance (TH, Anand).

In the end I bought 2x2G of DDR2-1000 (for some overclocking). Cost was one hundred US greenbacks (or is that purple and green backs now??)
 

dagger

Splendid
Mar 23, 2008
5,624
0
25,780
0



All the 1000mhz ddr2, and most of the 1066mhz ones are just factory oced 800mhz sticks. :p

And greenbacks are worth less and less those days. :na:
 

3Ball

Distinguished
Mar 1, 2006
1,736
0
19,790
1


He is correct in his statement. Though a 32bit environment has the ability to address up to 4gb of ram the windows environment specifically will generally only address around 3.25gb. Other people have gone deeper into so I feel that I dont really need 2. Hope this helps clear it up.

As for the OP I would either sell and get 2x2gb or just add another 2x1gb sticks so that even though you wont use it all you will be in good shape for a 64bit switch if you plan to. If you dont plan to then I would just go with the xtra 2x512 in order to keep the dual channel mode.

Best,

3Ball
 

williamleja

Distinguished
Jan 26, 2008
103
0
18,680
0
I was faced with a similar decision as the OP except I already had Windows XP x64 running on my system. I had 2x1GB sticks and I wanted to go to 4GB.

I was going to buy 2 more 1GB sticks to get to 4GB, but then I thought about it and figured that someday I may want to run 8GB of RAM and would not be able to. Furthermore, since I am not sold on Nehalem I wont be buying DDR3 for a while. Furthermore 2x2GB sticks of DDR3 are WAY to expensive!

In the end I bought 2x2GB of DDR2. They run just as fast as my 2x1GB sticks with a little tweaking. I bought Mushkin so they were more expensive (about $115 USD) but they were worth it.

To anyone building a computer in the future I recommend buying 2GB modules. That way you've always got room to grow WHEN 8gb of RAM is needed for everyday tasks. Set yourself up with either XP x64 or Vista x64 and you're golden.
 

ASK THE COMMUNITY