DDR memory questions

[energeticelectron]

What is the correct type of memory for a P4 with a 400Mhz FSB?

What's the different between single and double DDR?

What does all the PCthis and PCthat numbers mean? Like PC2700 or something, what do those numbers mean? Thanks.

 

[Corporate Thug]

for 400 mhz, you need pc3200 which is 200 mhz (but it is DDR so it runs at 400 mhz)

pc2100 = 133 mhz
pc2700 = 166 mhz
pc3200 = 200 mhz
pc3500 = 216 mhz
pc3700 = 233 mhz
pc4000 = 250 mhz
pc4200 = 267 mhz

Dual Channel DDR supposedly doubles the memory bandwidth and is NOT supported by ALL mobos. it is more or useless on the AMD platform (unless you are using onboard graphics), but does show a good amount of performance increase on systems based on the 865/875 chipsets

 

[sellmen]

Originally posted by: shady06
for 400 mhz, you need pc3200 which is 200 mhz (but it is DDR so it runs at 400 mhz)

pc2100 = 133 mhz
pc2700 = 166 mhz
pc3200 = 200 mhz
pc3500 = 216 mhz
pc3700 = 233 mhz
pc4000 = 250 mhz
pc4200 = 267 mhz

Dual Channel DDR supposidly doubles the memory bandwidth and is NOT supported by ALL mobos

Just to clarify, the number after the "pc" refers to the bandwidth the RAM provides in MB/sec, so pc2100 would provide 2100 MB/sec of bandwidth at it's rated speeds.

 

[energeticelectron]

Originally posted by: shady06

Dual Channel DDR supposedly doubles the memory bandwidth and is NOT supported by ALL mobos.

So is that what "Dual DDR 400" is?

Are there any recommended manufacturers for quality dual channel PC3200 DDR?

I took a look on Crucial and found this part: http://www.crucial.com/store/PartSpecs.asp?imodule=CT3264Z40B&cat=RAM

But it doesn't say if it's "dual channel" or not.

 

[Corporate Thug]

Originally posted by: energeticelectron

Originally posted by: shady06

Dual Channel DDR supposedly doubles the memory bandwidth and is NOT supported by ALL mobos.

So is that what "Dual DDR 400" is?

Are there any recommended manufacturers for quality dual channel PC3200 DDR?

I took a look on Crucial and found this part: http://www.crucial.com/store/PartSpecs.asp?imodule=CT3264Z40B&cat=RAM

But it doesn't say if it's "dual channel" or not.

as long as the it is the identical ram, any sticks of ram can be ran in dual channel. of course, corsair makes good stuff. look for twinX line, they come in pairs and are meant for dual channel use

 

[energeticelectron]

Originally posted by: shady06

as long as the it is the identical ram, any sticks of ram can be ran in dual channel.

I guess I still don't get the concept of "dual channel".

Does it just mean that you have two identical sticks of DDR?

Or can it be a single stick of DDR?

What is it that makes it "dual channel"?

 

[sellmen]

Originally posted by: energeticelectron

Originally posted by: shady06

as long as the it is the identical ram, any sticks of ram can be ran in dual channel.

I guess I still don't get the concept of "dual channel".

Does it just mean that you have two identical sticks of DDR?

Or can it be a single stick of DDR?

What is it that makes it "dual channel"?

Certain motherboards have a dual channel feature. They have two memory controllers, which can read or write on two banks of RAM simultaneously, effectively doubling the bandwidth. In order to use dual channel, you need to have an equal amount of RAM in each bank. The easiest way to accomplish this is by buying two identical sticks of RAM.

 

[energeticelectron]

Originally posted by: sellmen

Certain motherboards have a dual channel feature. They have two memory controllers, which can read or write on two banks of RAM simultaneously, effectively doubling the bandwidth. In order to use dual channel, you need to have an equal amount of RAM in each bank. The easiest way to accomplish this is by buying two identical sticks of RAM.

Great, that made sense. Thanks.

So, if I want a total of 256MB, I can get two sticks of 128MB and place them in the proper banks on the motherboard, and then presto I have "dual channel"....Got it. Thanks.

 

[mechBgon]

What motherboard are you getting?

 

[energeticelectron]

Originally posted by: mechBgon
What motherboard are you getting?

I think I'm getting the Abit IS7-M motherboard.

Either going to put a P4a 1.8Ghz or a P4-Celeron 2.4Ghz with total of 256MB of PC3200 memory.

 

[mechBgon]

In that case, I'd recommend either PC2100 or PC2700, unless you just want to pave the way for an 800MHz-based CPU like the Pentium4 2.4C. The 400MHz-based P4's and Celerons will have all the bandwidth they want even with just dual-channel PC2100. Spend the money you save on more RAM, I'd suggest two 256MB modules for a total of 512MB.

 

[energeticelectron]

Originally posted by: mechBgon
In that case, I'd recommend either PC2100 or PC2700, unless you just want to pave the way for an 800MHz-based CPU like the Pentium4 2.4C. The 400MHz-based P4's and Celerons will have all the bandwidth they want even with just dual-channel PC2100. Spend the money you save on more RAM, I'd suggest two 256MB modules for a total of 512MB.

I didn't even know that PC2100/2700 was compatible.

shady06 told me that I need PC3200 for my system.

So I have an option between all 3?

Is it really true that the P4a and P4-Celeron doesn't need more than PC2100? Because if that's the case, then I'll just take your advice and get 512MB of PC2100. But I just want to be sure that it's really true what you are saying, since what shady06 said seems to be contradicting.

EDIT: I just looked at the difference in price between 256MB stick of PC3200 and a 256MB stick of PC2100....and the PC2100 is only 3 dollars cheaper. Weird.!

 

[mechBgon]

Well my advice was an nForce 220D board with an AthlonXP but with a 400MHz-based CPU on a dual-channel-capable board, I think the CPU will have all the bandwidth it wants just with dual-channel PC2100. Definitely get the 512MB and dual-channel regardless, because WinXP will like that way better than 256MB (I assume WinXP here?).

Hang on and I'll research the issue in the IS7-M's owners' manual.

 

[energeticelectron]

Originally posted by: mechBgon
(I assume WinXP here?).

Actually, grandma's getting Linux. The next version of Red Hat Linux, to be exact.

But Linux is VERY memory hungry, so you are right that 512MB will come in handy.

But check out the price difference between PC3200 and PC2100 on www.crucial.com. It's like 3 dollars cheaper. If it's just 3 dollars cheaper, I'll probably go ahead and get the PC3200....

What I'm looking to do is prep her system for a future upgrade. Maybe in two years, the price of a P4c 3.0Ghz will be low enough where I can drop it in her system for $75 or whatever, and get a pretty substantial upgrade in performance.

 

[mechBgon]

Whoa! :Q They're charging less for PC2700 than for PC2100. Heck yeah, get PC3200 at that rate. You can plunk a 2.4C Pentium4 into it about 18 months from now as a nice upgrade.