Using all memory slots on motherboard

[Gsai2912]

Hi, I have a question about using all the memory slots on a motherboard. I keep reading that it is better to have for example:
2x2GB sticks of DDR2 memory occupying one slot each for a total of two slots used then it is to have 4x1GB sticks of DDR2 memory occupying one slot each for a total of four slots used. The reason I keep reading is its because it causes more stress to the motherboard or something.

Is this only the case if you plan on overclocking or in general? How much stress does it cause and what sort of stress?

I currently have 1GB of memory and recently purchased 2GB and wanted to use both sets of sticks so it would total 3GB using all 4 slots. Would I be better off just using the 2GB?

I'm using Windows XP 32bit currently and plan on going to Vista but not sure 32bit or 64bit. I do use a lot of video and photo editing software.

My PC is a Dell Dimension 9100
Chip: Pentium D 820
Motherboard: Intel Lakeport i945P
Ram: 1GB DDR2 533 CAS4

Thanks.

 

[Matthias99]

You may be forced to run at a lower memory speed if you populate all four slots. Your motherboard/system's documentation should tell you if this is the case. It may also limit overclockability.

It will not damage anything or cause undue "stress".

 

[Gsai2912]

Originally posted by: Matthias99
You may be forced to run at a lower memory speed if you populate all four slots. Your motherboard/system's documentation should tell you if this is the case. It may also limit overclockability.

It will not damage anything or cause undue "stress".

Is their a reason why the memory may run at a lower speed if all four slots are occupied? Since I'm not overclocking, I should be fine with running memory in all four slots then with the exception that it may not run at its rated speed? I can't really check motherboard/system docs as its a Dell PC and their manuals don't list things like that. Thanks.

 

[Matthias99]

Is their a reason why the memory may run at a lower speed if all four slots are occupied?

The memory controllers found on common desktop motherboards (or in Athlon64/Opteron CPUs for 'desktop' use) are generally built assuming the most common configuration will be either one or two sticks of memory. In order to keep costs down, they are not always robust or fast enough to drive four DIMMs at the tightest timings or highest speeds possible. Most new systems will not actually lower the clock speed, but may relax the DDR timings somewhat to ensure stability, resulting in performance a few percent lower. First-generation Athlon64s and some older Intel chipsets may drop you to DDR333 instead of DDR400.

On most 'enthusiast' motherboards you can try to force it back to the higher speed/tighter timings, although this may cause instability. With an OEM system the BIOS probably won't give you a choice.

Since I'm not overclocking, I should be fine with running memory in all four slots then with the exception that it may not run at its rated speed?

Pretty much.

I can't really check motherboard/system docs as its a Dell PC and their manuals don't list things like that.

It might, it might not. You could also try emailing or calling their tech support (although the first-level grunts are unlikely to know anything like this.) There are tools you can use from within Windows (like CPU-Z) to check the memory speed and timings even if the BIOS doesn't inform you when it boots up.

 

[Gsai2912]

Originally posted by: Matthias99

Is their a reason why the memory may run at a lower speed if all four slots are occupied?

The memory controllers found on common desktop motherboards (or in Athlon64/Opteron CPUs for 'desktop' use) are generally built assuming the most common configuration will be either one or two sticks of memory. In order to keep costs down, they are not always robust or fast enough to drive four DIMMs at the tightest timings or highest speeds possible. Most new systems will not actually lower the clock speed, but may relax the DDR timings somewhat to ensure stability, resulting in performance a few percent lower. First-generation Athlon64s and some older Intel chipsets may drop you to DDR333 instead of DDR400.

On most 'enthusiast' motherboards you can try to force it back to the higher speed/tighter timings, although this may cause instability. With an OEM system the BIOS probably won't give you a choice.

Since I'm not overclocking, I should be fine with running memory in all four slots then with the exception that it may not run at its rated speed?

Pretty much.

I can't really check motherboard/system docs as its a Dell PC and their manuals don't list things like that.

It might, it might not. You could also try emailing or calling their tech support (although the first-level grunts are unlikely to know anything like this.) There are tools you can use from within Windows (like CPU-Z) to check the memory speed and timings even if the BIOS doesn't inform you when it boots up.

I see, thanks for your help.

 

[stevty2889]

You'll be able to use all 4 slots just fine. It won't reduce the speed of the memory, A64's did that, but they had an onboard memory controller, pentium-d's do not. It's a dell so you don't have to worry about it limiting your overclock either. Not that it necessarily would. My overclock did not change any weather I used 1 or all 4 sticks with my quad core.

What you will notice however, is that you won't be able to use all 4gig of ram anyway with a 32bit OS. XP and 32bit Vista will only see it as ~3.25gb. 64 bit vista can use all 4 gig, but you might need to have a memory remapping feature in your bios for 64bit vista to see all 4 gig, not entirely sure though, as I just started using 4gig of ram myself recently. With the memory remap feature turned off in my bios, 64bit Vista only sees 3.25gb as well.

 

[Gsai2912]

Originally posted by: stevty2889
You'll be able to use all 4 slots just fine. It won't reduce the speed of the memory, A64's did that, but they had an onboard memory controller, pentium-d's do not. It's a dell so you don't have to worry about it limiting your overclock either. Not that it necessarily would. My overclock did not change any weather I used 1 or all 4 sticks with my quad core.

What you will notice however, is that you won't be able to use all 4gig of ram anyway with a 32bit OS. XP and 32bit Vista will only see it as ~3.25gb. 64 bit vista can use all 4 gig, but you might need to have a memory remapping feature in your bios for 64bit vista to see all 4 gig, not entirely sure though, as I just started using 4gig of ram myself recently. With the memory remap feature turned off in my bios, 64bit Vista only sees 3.25gb as well.

Yeah I knew about the memory limitations using a 32bit OS. I didn't know about the memory remapping feature though. At this point though, I'm not too worried yet since in total I only have 3GB of memory. Thanks for your help.