question about dual channel memory...

[prankster]

I guess this is embarrassing to ask this basic stuff. I already have 2x256 pc3200 dual channel memory in my machine. Would it be okay if I add another pair of dual channel memory (2x 512 pc3200)?

 

[larry89]

Yes it would, but you would be running at a 2T command rate which results in loss of memory bandwidth but the real world difference is unoticable, But your memory would also be running at ddr333.

 

[prankster]

Originally posted by: larry89
Yes it would, but you would be running at a 2T command rate which results in loss of memory bandwidth but the real world difference is unoticable, But your memory would also be running at ddr333.

Is it a bad thing to run in DDR333?

 

[SirBrass]

not necessarilly, but you would be running slower than if it were running in DDR400 like it can.

the thing with dual channel is that for max speed, use the same amount of memory in both channels and keep the same speed for all the sticks of RAM.

Example: I have 2 sticks of 512 MB DDR400 in my dual channel RAM slots. If I were to add more RAM, I'd add two MORE sticks of DDR400 RAM and have them be the same size in memory (not same size as the RAM already in, since it doesn't have to be that), and for sake of example, let's make these 2 new sticks 1 GB each. I'd stick 1 GB into each channel (for my mobo, each channel contains two RAM sockets. so I could have 4 GB RAM total if I wanted). now I have 1.5 GB RAM in each channel, and since it's all at DDR400, it'll run at DDR400.

 

[andy nowotny]

Sure you can, but for AMD Athlon 64, they will work at DDR400 2T, but not DDR333

 

[prankster]

So I shouldn't combine my 2x256mb pc3200 with 2x512mb pc3200?

 

[Googer]

Originally posted by: prankster
So I shouldn't combine my 2x256mb pc3200 with 2x512mb pc3200?

You can, but you will have less memory bandwith avalable that will result in a performace hit in some applications. If you have the newer San Deago or Venice cores (or anything newer) generaly speaking this will not affect you. Do it if you want no real harm will happen.

 

[RadiclDreamer]

I run DDR400 with 4 sticks. You just have to manually select it in the bios

 

[theMan]

Originally posted by: RadiclDreamer
I run DDR400 with 4 sticks. You just have to manually select it in the bios.

you have a revision E cpu then. the memory controllers in the older cpu's dont support that. and if you have it set in the bios without a new cpu, it probably isnt being implemented. check cpu-z.

i dont think it will be that bad, but if you are really into conserving every bit of power your computer has, it will just sell the other sticks. otherwise, dont worry.

 

[So]

Out of curiosity, would this apply to three sticks on a newcastle core? I have two sticks of 512 ATM and I'd like to go to 2 gigs, but I'd rather not scrap my existing ram...it's a s754, so I don't have dual channel issues to worry about anyway.

 

[prankster]

Originally posted by: theman

Originally posted by: RadiclDreamer
I run DDR400 with 4 sticks. You just have to manually select it in the bios.

you have a revision E cpu then. the memory controllers in the older cpu's dont support that. and if you have it set in the bios without a new cpu, it probably isnt being implemented. check cpu-z.

i dont think it will be that bad, but if you are really into conserving every bit of power your computer has, it will just sell the other sticks. otherwise, dont worry.

What is cpu-z? And how do you setup the memory in the bios?

 

[Googer]

Originally posted by: RadiclDreamer
I run DDR400 with 4 sticks. You just have to manually select it in the bios

What cpu core or revision are you running?

 

[prankster]

I believe it's winchester.

 

[RadiclDreamer]

Newcastle DH7-CG revision according to CPU-Z and it also confirms that its in dual 400 mode

 

[prankster]

Okay, I ran CPU-Z and it's telling me that my memory runs at pc3200 (200MHz) on slot#1. And the same thing on slot#2. Aren't they supposed to run at 400MHz?

 

[Concillian]

Originally posted by: So
Out of curiosity, would this apply to three sticks on a newcastle core? I have two sticks of 512 ATM and I'd like to go to 2 gigs, but I'd rather not scrap my existing ram...it's a s754, so I don't have dual channel issues to worry about anyway.

yes it does, 3 sticks + S754 is pretty unstable unless you put it into 2T command rate. For me it was even unstable using 2x256 and 2x512 so there were still 4 "sides" of RAM like in 2x512. No go, still very unstable.

Just put the memory in and use it in 2T, I doubt you will notice the difference unless you benchmark and compare the numbers benchmarks output.

 

[lxskllr]

Originally posted by: prankster
Okay, I ran CPU-Z and it's telling me that my memory runs at pc3200 (200MHz) on slot#1. And the same thing on slot#2. Aren't they supposed to run at 400MHz?

That speed gets doubled so 200mhz=400mhz
Double
Data
Rate

 

[Trizik]

Why does it get doubled?