Question about Dual Channel on E1505

Hi,

I've been looking at the E1505 (with the "Intel Core 2 Duo T7200 (2.00GHz, 4MB L2 Cache, 667MHz FSB) and was confused by the choices I had for the memory. The list is below:

1GB Shared Dual Channel DDR2 SDRAM at 533MHz, 2 Dimm [subtract $25]
1GB DDR2 SDRAM at 667MHZ, 2 DIMM [Included in Price]
2GB Shared Dual Channel DDR2 SDRAM at 533MHZ, 2 DIMM [add $125 or $3/month1]
2GB DDR2 SDRAM at 667MHZ, 2 DIMM [add $175 or $5/month1]

My question is... Is the 667MHz memory running Dual channel? If so, why aren't they stating this? It is only listed for the 533MHz stuff


Thanks,
--Fonz

 

Hello and Welcome here
These are the choices in order :
2x512MB memory in dual channel = 1GB
1x1GB memory in single channel = 1GB
1x2GB memory is dual channel = 2GB
2GB memory in single channel = 2GB.
(Unlike desktops, there is not much of a difference between single channel 2GB and dual-channel 2x1GB)

 

Not certain, but it says 2 DIMM, so I assume it's dual-channel and someone just forgot to type that in.
But before you upgrade the RAM on the dell site, consider that you can buy 2 GB of 667 MHz RAM for under $70 at newegg.com ($35 per 1 gb module). It's easy to install.

 

Thanks to both of you for your help!
So, what I have gathered from this is that:

1. Any speed of memory can run dual channel on this system, it's just a setting in the BIOS (So I can order and install two 667MHz Dimms and it will run dual-channel 667MHz FSB). If I use two 533MHz sticks, it will be dual-channel @533MHz FSB.

-and-

2. I should order with the cheapest memory configuration available and just upgrade the memory myself for much less.

Although, you state above that the increased performance is not as noticeable as with, say, my desktop computer... Why is that?

As I understand it, the FSB is the bus between the CPU and DRAM. So, if it runs at 667 (like the proc spec says "T7200 2.00GHz, 4MB L2 Cache, 667MHz FSB") then the memory would have to, right? Would the FSB only run at 533MHz if I were to get the 533MHz RAM?

Thanks again,
--Fonz

 

I'm not certain that this particular system supports dual-channel at 667 mhz, but I would expect so... so yeah, that's my understanding. I don't even think you have to set anything in the BIOS... I think it just detects the two identical sticks of RAM and runs it as dual-channel, but again, I'm not certain.

Yep. Newegg sells ram cheap, for example.

I'm curious to hear about this too... this surprises me.

Not certain, but as I understand it, the FSB is the bus between the CPU and most other things. So it's like a big highway. The highway speed limit is 667 mph (really fast, I know), but cars going between the cpu and ram can only go at 533 mph. Cars going between cpu and other destinations on the motherboard (for example, the GPU or USB controller) may be able to go at other speeds. Again, I'm not entirely sure about all the details here.

I'll also add that generally, nothing about the RAM matters nearly as much as the sheer amount of it. 533 vs. 667 mhz, dual-channel vs. single-channel... whatever. Accessing the hard drive takes about 100 times as long as accessing RAM, so if you have more RAM, it doesn't have to swap out to the HD as much, and things are much faster. The other stuff is nitpicking.

 

Thanks for the help... Now I have moved on to a Latitude D830 with 800MHz FSB. The only memory they offer is 667MHz! Any idea if I can populate this with 800MHz RAM? Would it be dual channel?

Thanks again!

 

Good choice stepping up to the Latitude...
I don't know of any computer vendors offering 800 MHz ram in laptops yet.
800 MHz laptop ram is brand spankin' new... and much more expensive.
As for whether you can upgrade it to 800 MHz ram... I don't know. See if the spec sheet for the D830 says anything about it. Also check if it supports dual-channel... I assume it does.

Again, I don't think ram speeds or dual-channel matter anywhere near as much as the amount of ram in there. I'd rather have 1.25 gb single channel 533 MHz ram than 1 gb dual channel 667 MHz ram, for example.

And you'll probably save money buying the ram at newegg instead of from dell.

 

Swarmer,

I've been trying to figure out the importance of dual-channel memory for quite a while. I've just purchased a D630 with a single 1GB DIMM through my university and I'm contemplating adding a second 2GB stick.

This means I'd lose dual channel, right? But you're saying that my performance this way would be *much* better than getting a second 1GB stick.

Also, if I decided to save money and just get another 1GB stick, is it likely to run dual-channel if it's a different manufacturer than the one I have.

Thanks!

 

No, no, no.

The short answer is: You should definitely get the second 1 gb stick of RAM and add it to your computer to have 2 gb total. You can get one for about $35 at newegg.com

The long answer:

With only one stick of ram you will NEVER have dual-channel. With two sticks of RAM you MIGHT get dual-channel.

The motherboard decides if the two sticks are similar enough to run in dual-channel. The more similar the two sticks of RAM are, the more likely it is to run in dual-channel. Some motherboards may be more tolerant of differences than others.

For the best chance of getting dual-channel, discard the 1 gb your computer came with and buy a matched pair of 2x1gb sticks. However, personally I would NOT do this because...
Dual-channel just doesn't matter all that much. The exception may be in hardcore gaming, which you won't be doing too much of on the D630.
Having a larger amount of ram is much more important than dual-channel, or any other details about the ram.

I mean, all else equal dual-channel is great but I wouldn't spend real money on it.

 

Thanks. I've been trying to get a straight answer about this for a while. I think I'll just pick up a newegg 1GB stick and consider swapping it out for a 2GB stick (or a pair if I decide to make the switch to 64 bit) later when prices fall.

I'm not worried at all about gaming (hence my D630, integrated graphics purchase), but I do run some intensive statistical and mathematical programs and thought that the extra memory might be useful there.

 

Cool... Let us know what you think of the D630 when you get it.