dual channel memory tech.

[ajimi]

hi guys... i need to know what is dual channel memory tech. for.
can i used for blue slot other type ddr than lack slot.

[chinobino]

Originally Posted by ajimi

hi guys... i need to know what is dual channel memory tech. for.
can i used for blue slot other type ddr than lack slot.

Hi ajimi, you need to give us more information. What RAM do you have? brand, speed, latencies etc...

Dual channel memory technology effectively doubles your memory bandwidth by providing 2 individual 64-bit channels that allow a total of 128-bits to be read or written from the memory bus per CPU clock cycle. For this reason dual channel memory configurations will provide increased performance over single channel configurations.

To achieve optimal Dual Channel mode, the following conditions should be met:

1. Same DRAM DIMM Speeds (PC3200, PC2700, PC2100)*
2. Same Density (128MB, 256MB, 512MB, etc.)
3. Same DRAM DIMM latencies e.g. 3-3-3-8 matched to 3-3-3-8
4. Same DRAM bus width (x8 or x16)
5. All DIMM pairs must be either both single-sided or both dual-sided
6. Matched DIMMS in both Channel A and Channel B memory channels when using 4 DIMMS.
7. Populate correct memory slots (Both blue, both black)

*Memory channel speed is determined by the slowest DIMM module populated in the system.

Note: Configurations that do not match the above conditions may revert to single channel mode.

The following conditions do not need to be met BUT will most likely effect performance:

1. Same brand
2. Same timing specifications (particularly if you use Serial Presence Detect)
3. Same DDR speed

Hope that helps .

[ajimi]

thanks for the info mate.
BTW what is the type of RAM shall i buy.

[chinobino]

For the Asrock 939 DSII I recommend Corsair XMS, with Samsung TCCD chips. They require low voltage and are good quality RAM. Others may like to recommend something else... but I haven't had any problems with this RAM and the Asrock 939 DSII, which can be picky about memory.

[bernek]

Originally Posted by chinobino

Hi ajimi, you need to give us more information. What RAM do you have? brand, speed, latencies etc...

Dual channel memory technology effectively doubles your memory bandwidth by providing 2 individual 64-bit channels that allow a total of 128-bits to be read or written from the memory bus per CPU clock cycle. For this reason dual channel memory configurations will provide increased performance over single channel configurations.

To achieve optimal Dual Channel mode, the following conditions should be met:

1. Same DRAM DIMM Speeds (PC3200, PC2700, PC2100)*
2. Same Density (128MB, 256MB, 512MB, etc.)
3. Same DRAM DIMM latencies e.g. 3-3-3-8 matched to 3-3-3-8
4. Same DRAM bus width (x8 or x16)
5. All DIMM pairs must be either both single-sided or both dual-sided
6. Matched DIMMS in both Channel A and Channel B memory channels when using 4 DIMMS.
7. Populate correct memory slots (Both blue, both black)

*Memory channel speed is determined by the slowest DIMM module populated in the system.

Note: Configurations that do not match the above conditions may revert to single channel mode.

The following conditions do not need to be met BUT will most likely effect performance:

1. Same brand
2. Same timing specifications (particularly if you use Serial Presence Detect)
3. Same DDR speed

Hope that helps .

PLEASE HELP ME :)

I'm desperately trying to make my systems stable ...

First I have:

1 x 512 MB Geil 2.5 4 4 8 (bought today)
1 x 512 MB Geil 2.5 3 3 6 (bought six months ago)
2 x 512 MB Geil Dual Channel KIT (bought 1 year ago)

The problem is that I can work in dual channel mode but I can't pass Prime95 and RMMA can allocate enough memory only 1437 MB can be tested ... anything above that is not ok ... (free is 1759)

I've tryied a lot of BIOS settings high voltage changed the ram position on motherboard ... used very relaxed timmings used the flexibility option ...

sometimes the memory placement on the mobo gives me only single channel but memory cannot be tested integral 1759 free only 1437 each time ...

I said and I repeat myself I've tried all the CAS Latency and all the settings in bios knowing what I'm doing ... believe me

I've wrote the bios again 2.20 I've cleared the CMOS ... I've tryied almost anything human possible :) YOU ask me please if I did something maybe I forgot a thing ...

I've even tested the ram in 1 piece at a time 512 MB only and in 2 x 512 configurations and in everyslot possible ...

The ram ONLY fails when 4 dimms are present 4 x 512 ...

give me some ideeas or something ... I've payed a lot for this RAM in my country and I can't afford to buy new one .... (romania sks I know ...)

[CrazyRhino]

pls use memtest86+ to test your sticks one by one. i am suspecting one of your stick is bad. just run them at DDR400 2.5-4-4-8-2T and see if you are getting any errors during memtest86+.

btw, you do know when using 4 sticks you can only use 2T?? 1T is not supported when all 4 dimm are populated and if you do that it WILL definitely give you memory error.

[bernek]

Originally Posted by CrazyRhino

pls use memtest86+ to test your sticks one by one. i am suspecting one of your stick is bad. just run them at DDR400 2.5-4-4-8-2T and see if you are getting any errors during memtest86+.

btw, you do know when using 4 sticks you can only use 2T?? 1T is not supported when all 4 dimm are populated and if you do that it WILL definitely give you memory error.

Thank you very much for replying :)

I will test them tomorrow ... now I'm too tired :(

I WILL POST BACK !

thank you very very much !

[bernek]

I've changed my mind I will test them right away !!!

1 by 1 using memtest86+ 1.65

I've tested each module and there was NO errors ...

I've tested 2 x 512 in each slots (blue or black) no errors ...

I've tested 4 x 512 and "block move" test 5 gave a lot of errors ...

here is a picture:

[bernek]

If I mess up with memtest settings I get with 4 x 512 errors at 2047 mb and here and sometimes everywhere ...

seems there is no way for me now ...

[CrazyRhino]

from your memory bandwidth, it looks like you are using 1T, are you?