The Joys Of Dual Channel DDR???

[hoodrich]

Hi guys its time to play spot the newb, as i ask randomly easy questions that i am having trouble understanding. Your specialist subject today is...... Dual Channel DDR! please take the hotseat (que big black leather chair and magnus magnuson style gameshow host). Ok masterminds help me out here as i pick at your brains like an amazon botfly.

1. I have just ordered the parts for a new system build (its been a while since i did much in I.T. and back then 1.2ghz was unbelieveabley fast, so excuse any lack of knowledge!). The system will eventually follow this spec...

intel P4 2.8ghz 800fsb
intel D865PERLL i865PE 478 DDR
ATI Radeon 9800pro 128mb
512mb Crucial DDR400 (pc3200) single stick. unbuffered,non parity, cl=3
400W PSU
Creative SB 1024 card

My question is this... The motherboard states that it supports Dual Channel DDR (if someone can verify this for me it would be appreciated). I would like to know the benefits of running dual channel, how it works (ie. is it a second identical memory stick in the second Dimm slot?) Does it require any configuration to get it going - bios changes alterations? Will it make a noticable difference running the extra 512mb stick making a total of 1gb DDR400 in dual channel? I use the machine for hardcore gaming and love good graphics and smooth fps.

I made this sound like there were gonna be more questions but i accidently bundled them all into the first one in my haste. Oh well!

Cheers guys

Magnus mag..... sorry, Dave Morey

"I know Kung Fu......... Show Me"

 

[Crashman]

OMG! OK, here's the deal. You have a CPU bus of 200MHz clock rate, using Quad Data Rate for "800MHz" as measured in actual data transfers. You'll have PC3200 with a bus of 200MHz clock rate, using Double Data Rate for "400MHz" as measured in actual data transfers.

800/2=400. Since both are 64-bit busses, your RAM is half the bandwidth of your CPU bus. Dual Channel operation corrects this problem by pairing two stick of RAM in parallel, giving you a 128-bit memory bus:
800x64 = 400x128.

So dual channel is the only way to make your RAM have the same bandwidth as your CPU bus. This provides a fairly significant performance increase.

The motherboard manual will tell you which slots to put the two modules in for dual channel operation, probably slots 1 and 3.

1GB is definately better than 512MB under Windows XP. If you can't afford that, consider 2 256MB modules...

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<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[hoodrich]

Crashman it would appear that you have come to my rescue again. I really appreciate you taking the time to explain this to me now i understand what must be done.... a 512mb purchase is about to be made.

Cheers buddy

p.s you seem to be a man of great electronic knowledge, any thoughts on my new system spec? im hoping it should fly when its all assembled.

"I know Kung Fu......... Show Me"

 

[Crashman]

Your system will fly proudly. As for me, I'd save a few dollars and get a couple extra features by going with an Abit IS7 instead.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[mpjesse]

Boy, aren't you the popular one? =D

-Jesse

"Signatures Still Suck"

 

[Crashman]

Ha! An expert like you could be a god to the newbies, but do you ever say anything?

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[addiarmadar]

Dont whine if you go about the mobo rating and will not work in dual channel mode. Stinkin nforce 2 mobos have a habbit of making error when going over 400fsb with dual channel enabled.

Barton 2500+ @ 2200mhz (10x220 vcore @ 1.775)
Asus A7N8X Dlx 440 FSB
1gb Geil GD pc3500 Dual Channel (2-3-3-6)
Segata 80gb SATA 8.5ms seek
ATI Radeon 9800 Pro(420/700)