- Joined
- Apr 25, 2002
i was going to say NOOBIES but i thought that was a little offensive 
Oh well i had extra time on my hands.. ya know being in spring break and all, and it seems people have a lot of questions on this topic so i figure meh why not eh?
This little thread will answer popular questions on dual channel.
What is dual channel DDR?
When a dual channel memory system is setup, half of the data goes to your first memory stick, the other half goes to your second memory stick. (Almost like RAID) Because of this, your memory bandwidth is doubled (as now you have 2 chips working together as one! twice the power ? )
How can i get Dual Channel?
Getting a dual channel setup is quite easy. Firstly make sure that your motherboard is capable of dual channel. Currently in the AMD market the only motherboard chipset that i know of that supports dual channel is the nforce2 and the neforce (the first chipset to introduce dual channel! CONGRATS NVIDIA!)
In the intel market,
875P
865PE
E7205
845G (on some boards.... rumors have it...)
Sis 655
Next get two sticks of ANY and i'll say it again ANY ram (obviously it has to be ddr... hence came the term dual channel ddr). Note I reccomend the two ram chips must be EXACTLY THE SAME! the same ram timings, the same speed, if one is double sided, the other must be double sided, if one is single sided the other must be single sided,etc, as this will give you the best performance.
"You can use different size and brand and speeds, its just as slow as the slowest stick. If you have a 256mb stick and a 512, u would get 512mb of dual channel." (Quote from TheFrag). The 256mb that remains will be run in single channel.
Read your motherboard manual (i know the horror!) and find out which two dimm slots will enable dual channel to work. (For example on my a7n8x deluxe, dimm slot 1 and dimm slot 3 or dimm slot 2 and dimm slot 3 will enable dual channel) and put the two sticks of ram within these 2 slots.
That's all there is to it!
Hey Dual Channel is great and All, but lets say i add another ram stick to the mix is it still in dual channel mode?
The Answer is yes... For example my A7N8X only has 3 dimm slots... so lets say i have 2 sticks of that kingston pc2100 running in dual channel mode. I now have a craving for more ram, so i buy some kingston hyperx pc3500 no biggy, i put it in the slot currently not occupied by ram, and that's it. When data is passed through the sticks in dual channel mode, it will travel at the rate of the dual channel sticks... however when it is passed through the stick not in dual channel it will travel at that speed... it's like having a hybrid dual channel setup... Will performace take a hit? of course! But it'll be worse than true dual channel but better than just single channel ram...
So why do i need dual channel?
No one said you NEED it... it's just good to have! Dual channel ddr gives more memory bandwidth, making it capable of feeding that bandwidth hungry processor (especially that p4 sssshhhh) of yours!
So is dual channel ddr faster than having regular a regular ram setup?
Yes
Well my ram is currently running at or faster than my cpu's fsb so will dual channel ddr show any performance boost?
Well it all depends... Generally the answer is yes, you will see a performace boost. It won't be anything HUGE! maybe 5 % maybe 20% maybe even more.. all depends (my little way of saying its uncertain exactly how much)
So from what you said before, will dual channel be worthless on an amd system?
No NOT WORTHLESS! when figuring out the speed ddr ram is going at you follow the equation fsb *2 so standard athlon xp not overclocked is at a 133mhz bus *2 gives it the 266mhz bus... (so there's really no point to buy pc2700 or higher on an athlon xp system that isn't overclocked...) A Pentium 4 however runs on a quad pumped fsb. so let's take the p4 b's they run on a 133mhz bus just as the athlons do so since quad means 4 simple multiplication 133*4=532..... hence comes the 533 mhz bus (ya crazy intel adding one more mhz!)
with dual channel ddr enabled,your ram is running twice as fast. so on an amd system... if your processor was at a 133mhz bus... your memory would be calculated as 133*2*2 which is suppossedly 532mhz however your processor works at the 266mhz bus.... so lets see 532-266=266.... so your memory bus is theoretically running 266mhz faster than your processor bus... while without dual channel ddr, your processor AND memory would be running at the same bus speed... (266 mhz in this scenerio). Because of this, people say that really athlons don't need dual channel, as the ram already travels as fast as the cpu!
On a Pentium 4 however, it is a totally different case! If you have a pentium 4 which runs on a quad pumped fsb... of 533 while your ddr is running at 266mhz your memory is going slower than your processor! Thereby running your ram in dual channel ddr your memory is going the same speed as the processors fsb... thereby giving a greater performance boost than the Athlons.
I hope that was confusing... i tried to make it not confusing but i just couldn't get how else to say it...
Those are the qestions i saw being asked the most.... coulda been others... If you would like to contribute a question to this faq then be my guest i'll try to answer it... or maybe another forummer with post the answer (ya like that'll ever happen).
ALSO if I HAVE MADE ANY MISTAKE IN ANSWERING A QUESTION, OR IF I MISSED SOMETHING OUT OR YOU JUST WANNA PLAIN OL ADD SOMETHING JUST TELL ME AND I'LL CHANGE IT!
Oh well i had extra time on my hands.. ya know being in spring break and all, and it seems people have a lot of questions on this topic so i figure meh why not eh?This little thread will answer popular questions on dual channel.
What is dual channel DDR?
When a dual channel memory system is setup, half of the data goes to your first memory stick, the other half goes to your second memory stick. (Almost like RAID) Because of this, your memory bandwidth is doubled (as now you have 2 chips working together as one! twice the power ?
)How can i get Dual Channel?
Getting a dual channel setup is quite easy. Firstly make sure that your motherboard is capable of dual channel. Currently in the AMD market the only motherboard chipset that i know of that supports dual channel is the nforce2 and the neforce (the first chipset to introduce dual channel! CONGRATS NVIDIA!)
In the intel market,
875P
865PE
E7205
845G (on some boards.... rumors have it...)
Sis 655
Next get two sticks of ANY and i'll say it again ANY ram (obviously it has to be ddr... hence came the term dual channel ddr). Note I reccomend the two ram chips must be EXACTLY THE SAME! the same ram timings, the same speed, if one is double sided, the other must be double sided, if one is single sided the other must be single sided,etc, as this will give you the best performance.
"You can use different size and brand and speeds, its just as slow as the slowest stick. If you have a 256mb stick and a 512, u would get 512mb of dual channel." (Quote from TheFrag). The 256mb that remains will be run in single channel.
Read your motherboard manual (i know the horror!) and find out which two dimm slots will enable dual channel to work. (For example on my a7n8x deluxe, dimm slot 1 and dimm slot 3 or dimm slot 2 and dimm slot 3 will enable dual channel) and put the two sticks of ram within these 2 slots.
That's all there is to it!
Hey Dual Channel is great and All, but lets say i add another ram stick to the mix is it still in dual channel mode?
The Answer is yes... For example my A7N8X only has 3 dimm slots... so lets say i have 2 sticks of that kingston pc2100 running in dual channel mode. I now have a craving for more ram, so i buy some kingston hyperx pc3500 no biggy, i put it in the slot currently not occupied by ram, and that's it. When data is passed through the sticks in dual channel mode, it will travel at the rate of the dual channel sticks... however when it is passed through the stick not in dual channel it will travel at that speed... it's like having a hybrid dual channel setup... Will performace take a hit? of course! But it'll be worse than true dual channel but better than just single channel ram...
So why do i need dual channel?
No one said you NEED it... it's just good to have! Dual channel ddr gives more memory bandwidth, making it capable of feeding that bandwidth hungry processor (especially that p4 sssshhhh) of yours!
So is dual channel ddr faster than having regular a regular ram setup?
Yes
Well my ram is currently running at or faster than my cpu's fsb so will dual channel ddr show any performance boost?
Well it all depends... Generally the answer is yes, you will see a performace boost. It won't be anything HUGE! maybe 5 % maybe 20% maybe even more.. all depends (my little way of saying its uncertain exactly how much
)So from what you said before, will dual channel be worthless on an amd system?
No NOT WORTHLESS! when figuring out the speed ddr ram is going at you follow the equation fsb *2 so standard athlon xp not overclocked is at a 133mhz bus *2 gives it the 266mhz bus... (so there's really no point to buy pc2700 or higher on an athlon xp system that isn't overclocked...) A Pentium 4 however runs on a quad pumped fsb. so let's take the p4 b's they run on a 133mhz bus just as the athlons do so since quad means 4 simple multiplication 133*4=532..... hence comes the 533 mhz bus (ya crazy intel adding one more mhz!)
with dual channel ddr enabled,your ram is running twice as fast. so on an amd system... if your processor was at a 133mhz bus... your memory would be calculated as 133*2*2 which is suppossedly 532mhz however your processor works at the 266mhz bus.... so lets see 532-266=266.... so your memory bus is theoretically running 266mhz faster than your processor bus... while without dual channel ddr, your processor AND memory would be running at the same bus speed... (266 mhz in this scenerio). Because of this, people say that really athlons don't need dual channel, as the ram already travels as fast as the cpu!
On a Pentium 4 however, it is a totally different case! If you have a pentium 4 which runs on a quad pumped fsb... of 533 while your ddr is running at 266mhz your memory is going slower than your processor! Thereby running your ram in dual channel ddr your memory is going the same speed as the processors fsb... thereby giving a greater performance boost than the Athlons.
I hope that was confusing... i tried to make it not confusing but i just couldn't get how else to say it...
Those are the qestions i saw being asked the most.... coulda been others... If you would like to contribute a question to this faq then be my guest i'll try to answer it... or maybe another forummer with post the answer (ya like that'll ever happen
).ALSO if I HAVE MADE ANY MISTAKE IN ANSWERING A QUESTION, OR IF I MISSED SOMETHING OUT OR YOU JUST WANNA PLAIN OL ADD SOMETHING JUST TELL ME AND I'LL CHANGE IT!
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