Dual-Channel + 1?

[Casper1676]

I am wondering something...

Lets say that I get an ASUS a7n8x delx. mobo and it has 3 dimm slots. I buy a pair of kingston hyperX 512mb modules (total 1024mb) and they are working in dual-channel (in slot 1 and 2 or in slot 1 and 3). Then a year later I buy another 512 or 1024mb modules (it maybe the same kingston kyperX module or a completely different brand) for the last slot as an upgrade. Will i still have dual-channel? if so, how will it work?

Thanks

[flachebaq]

A board would have to have an even number of DIMM slots for dual channel. After looking on the Asus web site, it appears that the board you are speaking of only has two slots.

Now, to answer your question, we'll assume that you have a board with four slots; as I stated before, you have to have pairs for dual channel DDR. If you start off with two sticks of 512 MB that will give you 1024 MB of RAM. Now, if you decide later that you need more, it is better for you to add a pair than just one stick. If you add just one stick, your RAM will back down to single channel and give you a noticable performance hit. I shaved about 1.5 seconds off the boot time of a P4 2.6 GHz with 512 MB of RAM running Windows XP Pro. just by switching from single to dual channel.

That said, make sure that your pairs are the same vitage and even out of the same batch if possible. I work for a company that builds computers and I can say that dual channel DDR does work better if you match the RAM as closely as possible. If you don't, the average person may not notice, but complex activities like rendering in something like Blender or Premiere, or copiling software will slow down slightly. It may seem trivial, but when something I have from my college days using Blender can be rendered 4 to 15 minutes faster depending on the RAM configuration, I can say it is definitely better to get the RAM paired correctly.

[Casper1676]

...

If you add just one stick, your RAM will back down to single channel and give you a noticable performance hit.

...

That is all i wanted to know. The asus board has three ram slots on it (i don't know what you were looking at). only two of them (any two 1/2 or 1/3) act as dual-channel. Yes i would buy the modules at the at the sametime. over 70% of what you wrote, i put in my post (::like to hear yourself talk much:

anyway...thanks for the reply. that is what i was thinking but i was not completely sure.

[flachebaq]

Sure, I love to hear myself talk... don't you like to hear me talk!?!?!?

Sorry, I just did a quick glimpse at the Asus mobo's and I didn't look close enough to see that particular motherboard. Personally, I would stay away from that board because of the three slot thing. The engineer(s) that designed that board obviously didn't have a full grasp of dual channel memory. Just because of the design of the board (i.e. three DIMM slots), I would have to think that you may have some performance loss.

Personally, I tend to stick with the Intel stuff. Their processors and motherboard have a full three year warranty which very few of the manufacturers bother to match these days. They also tend to perform better straight out of the box and have less problems over the long term.

[Casper1676]

Yeah i do think it is weird that it only has 3 slots. well the intel boards are ok but intel chips are alot of money for not that much performance differences (unless you are wanting insane floating point). That asus board is one of the faster ones out there. it comes with a 3 year warranty along with the processor (retail) too. but you are making me think about the 4 slots now versus the two. mmmmmmmmm.....

Thanks

[falcon2000]

Originally posted by flachebaq
A board would have to have an even number of DIMM slots for dual channel. After looking on the Asus web site, it appears that the board you are speaking of only has two slots.

Actually, the nForce's implementation of the Dual Channel is different from that of the RDRAM and you don't need to have even numbers RAM slots for it to work. The Asus A7N8X Deluxe actually have 3 slots, not 2. Same for all nForce boards. They all have 3 slots.

And, yes, you can put in the third stick of RAM and get Dual Channel. But

Originally posted by Casper1676
They are working in dual-channel (in slot 1 and 2 or in slot 1 and 3) ... only two of them (any two 1/2 or 1/3) act as dual-channel.

actually for Dual Channel to work the sticks have to be in slot 1 & 3 or slot 2 & 3 or slot 1-2 combo and 3. Never slot 1 and 2 alone (see the note in section 2.5.2 in the Asus manual) b/c for Dual Channel to work the sticks are to be in different "channels." Slot 1 & 2 are in the same "channel" while slot 3 is in the other.

Having said that, the best way to fully utilize Dual Channel in your case is to buy a 1G stick rather than another 512MB stick and put it in slot 3.

[Casper1676]

Thanks Falcon!!!

HAHA!!! I guess I should have just downloaded the manual in the first place. Well I am glad to know that if you have three modules on the mobo that it will use all of them as dual-channel. So if the first two modules are the exact same dimms and the third one is a different brand and size will it would with the other too (i think you answer it i just want you or someone to explain it more).

Thanks

[Casper1676]

I know that this has nothing to do with this subject but i am going to building myself a machine right after christmas (end of the year sales...would there be a better time with cheaper prices?) and what do you think of the system?

Coolermaster ATC-201C
ASUS A7N8X Deluxe
Athlon 2700+ (333MHz FSB)
Thermaltake"Silent Boost" HSF
1GB (512x2) Kingston HyperX P2700 (333MHz)
Samsung SM-352BRNS cdrw/dvd reader
ATi 9800 Pro w/ 128MB
Floppy (blah)
probably a flash media card reader
one HD

I know this system is going to use a lot less than 300W but i am not totally sure what size psu to get? I would like a 350 but i have been looking Zalman (300W) beause they are quiet, quality, and they have active PFC. Fortron has a 350W unit with active PFC but it is pushing in the $70 range.

What do you guys think?

[falcon2000]

Originally posted by Casper1676
So if the first two modules are the exact same dimms and the third one is a different brand and size will it would with the other too

Yes, in theory. That's what nVidia says about its cross-bar memory technology. But in practice you'll hae a lot less trouble if you would stick to the same brand and size.

BTW, the nForce boards are very picky when it comes to RAM. I would go to Asus and see which ones they have tested to work with the A7N8X Deluxe. Also check out this forum for FAQ and such.

The rig looks great. Wish I'll get one for X'Mas.

[flachebaq]

It is hard to tell when the best time to buy something is. Usually, with the Intel stuff you can wait until when the new round of chips is coming out... a price decrease is just around the corner for the current stuff. Usually, when new product is coming out, the old stuff gets marked down.

[Casper1676]

flachebaq, thanks for the time frame. We all know that the Athlon64 comes out on the 23rd and I am hoping that XP prices will drop a crapload so that I an afford a 3200

Does anyone have an ASUS A7N8X Deluxe mobo with Kingston HyperX 512MB x2 (total 1024MB) modules (2-2-2-5)?

Any thoughts on the PSU size?

Thanks