Expired

Need help with DDR2 1066Mhz Ram

21 replies
Found 19th Feb 2009
i recently brought a new asus m3n78 motherboard and a AMD Athlon X2 7750 Black
Edition which both support DDR2 1066Mhz Ram but it states in the Mobo Manual

"Due to AMD CPU limitations, DDR2 1066 is supported by AM2+ CPU for one DIMM per Channel only."

Does this mean i can only have one stick of ram ?

here are some links

CPU - overclockersclub.com/rev…htm

Mobo - asus.com/pro…u=2

Ram - kingston.com/hyp…asp

i will leave rep for anyone who can help me

Thanks

21 Comments

Original Poster

here a pdf for the memory page in the mobo manual

sharebee.com/fff…126

I would say that on normal motherboards with DDR/DDR2 that have 4 memory slots, that it's 2 slots per channel. Therefore with the limitation you have with the above, if you wanted 2 sticks running at 1066 Mhz you would need to put one in slot 1/2 and the other in slot 3/4 (I've the same config on mine which has dual channel architecture and have them in slots 1 and 3).

Looking at the image, this is why the slots are colour coded - the yellow slots will be the first channel and the black the second channel.

Original Poster

Xb0xGuru;4423486

I would say that on normal motherboards with DDR/DDR2 that have 4 memory … I would say that on normal motherboards with DDR/DDR2 that have 4 memory slots, that it's 2 slots per channel. Therefore with the limitation you have with the above, if you wanted 2 sticks running at 1066 Mhz you would need to put one in slot 1/2 and the other in slot 3/4 (I've the same config on mine which has dual channel architecture and have them in slots 1 and 3).Looking at the image, this is why the slots are colour coded - the yellow slots will be the first channel and the black the second channel.



thanks for that rep added :thumbsup: would i be able to have just one stick of 1066Mhz ram in then or do i need two ?

scott160592;4427998

thanks for that rep added :thumbsup: would i be able to have just one … thanks for that rep added :thumbsup: would i be able to have just one stick of 1066Mhz ram in then or do i need two ?



You want two - that way it can use 'dual-channel' operation for twice the bandwidth. One on its own will work, but at effectively half the speed of two. You can still use 4 sticks if you want, but they will operate at slower DDR2-800 speed (which to be honest won't make that much difference!).

jah128;4428064

You want two - that way it can use 'dual-channel' operation for twice the … You want two - that way it can use 'dual-channel' operation for twice the bandwidth. One on its own will work, but at effectively half the speed of two. You can still use 4 sticks if you want, but they will operate at slower DDR2-800 speed (which to be honest won't make that much difference!).



Are you sure about this? it's 1066Mhz per channel, meaning the one DIMM will run at this speed and if the OP wants another DIMM added and run at the same speed, he'll need to put it into one of the slots on the other channel?

Original Poster

Xb0xGuru;4428141

Are you sure about this? it's 1066Mhz per channel, meaning the one DIMM … Are you sure about this? it's 1066Mhz per channel, meaning the one DIMM will run at this speed and if the OP wants another DIMM added and run at the same speed, he'll need to put it into one of the slots on the other channel?



now im even more confused, if i have two in the same DIMM will that work at 800Mhz or at 1066Mhz

Original Poster

If i can only have one stick of DDR2 1066Mhz Ram in each channel would i be better haveing 2 DDR2 800Mhz Ram in the same channel ?

scott160592;4428335

now im even more confused, if i have two in the same DIMM will that work … now im even more confused, if i have two in the same DIMM will that work at 800Mhz or at 1066Mhz



You've 4 DIMM slots.

2 x Yellow
2 x Black

The difference in colour indicates a different channel.

If you put a 1066Mhz DIMM in a yellow slot, it'll run at 1066MHz.
If you want to add another 1066Mhz and have them both running at 1066Mhz, you need to add it to a black slot (1 DIMM slot per channel, as per the limitations).

Another point of note is unless you're running a 64 bit Operating System, you'll only be able to address a maximum of 3GB total RAM (including GPU card). Therefore unless you're going down the x64 route, there's not much point at the moment in getting more than 2GB RAM.

The CPU supports 'dual-channel' memory where two sticks are essentially address simultaneously - both operate at the same speed but work in parallel. If you have only a single stick of memory in total, it will still work, but in 'single-channel' mode, so essentially half the amount of data is transferred each time. The CPU supports 1066MHz ram, but only 1 stick per channel - so if you want to use your ram at 1066MHz speed you need 2 (identical) sticks for dual-channel operation, and you put one stick in each channel. If you want to use 4 sticks of ram in total, it will work, but it will lower the speed to 800MHz.

So the best thing for speed is 2 sticks of DDR2-1066, one in each channel. If you want to add more memory it will run a bit slower (but to be honest the memory clock speed doesn't make that much difference overall anyway for most tasks, a few % at most...)

Xb0xGuru;4428141

Are you sure about this? it's 1066Mhz per channel, meaning the one DIMM … Are you sure about this? it's 1066Mhz per channel, meaning the one DIMM will run at this speed and if the OP wants another DIMM added and run at the same speed, he'll need to put it into one of the slots on the other channel?


Yeah, I meant half the throughput really (speed was a bit misleading) - a single stick of ram would still work at 1066MHz but the data-rate would be half that of two sticks, one in each channel for dual-channel mode....

jah128;4428709

Yeah, I meant half the throughput really (speed was a bit misleading) - a … Yeah, I meant half the throughput really (speed was a bit misleading) - a single stick of ram would still work at 1066MHz but the data-rate would be half that of two sticks, one in each channel for dual-channel mode....



Yep, I get that, but because using both channels doubles the throughput doesn't mean the OP would lose out on just using one as this is exactly the same rate as a standard non-dual channel board would cope with. It's also worth noting the dual channel doesn't actually give twice the performance as indicated - I found this wiki page which is worth a read for anyone curious enough to do so!

en.wikipedia.org/wik…ure

Xb0xGuru;4428984

Yep, I get that, but because using both channels doubles the throughput … Yep, I get that, but because using both channels doubles the throughput doesn't mean the OP would lose out on just using one as this is exactly the same rate as a standard non-dual channel board would cope with. It's also worth noting the dual channel doesn't actually give twice the performance as indicated - I found this wiki page which is worth a read for anyone curious enough to do so!http://en.wikipedia.org/wiki/Dual-channel_architecture



Thats a bit misleading though - it does actually give pretty close to twice the memory data-rate, its just that memory data rate isn't necessarily that big a deal (it is a bit more so than when the THG article was made though). A high speed dual-or-quad core CPU will definately be bottlenecked by single-channel ram (hence why Intel have moved to triple-channel DDR3 with the i7); put it this way - a dual-channel 800MHz configuration would well outperform a single-channel 1066MHz setup. Its been quite a long time since a single-channel setup was 'standard' on a desktop platform (socket-754 for the earliest Athlon 64s, which was pretty obsolete by mid-2006...) - all AMD socket 939, AM2, AM2+ CPU's support dual-channel memory.

jah128;4429079

Thats a bit misleading though - it does actually give pretty close to … Thats a bit misleading though - it does actually give pretty close to twice the memory data-rate, its just that memory data rate isn't necessarily that big a deal (it is a bit more so than when the THG article was made though). A high speed dual-or-quad core CPU will definately be bottlenecked by single-channel ram (hence why Intel have moved to triple-channel DDR3 with the i7); put it this way - a dual-channel 800MHz configuration would well outperform a single-channel 1066MHz setup. Its been quite a long time since a single-channel setup was 'standard' on a desktop platform (socket-754 for the earliest Athlon 64s, which was pretty obsolete by mid-2006...) - all AMD socket 939, AM2, AM2+ CPU's support dual-channel memory.



I think that's what's called a well constructed argument ! :thumbsup:

Original Poster

Xb0xGuru;4429181

I think that's what's called a well constructed argument ! :thumbsup:



right just to make sure if i buy these web-systems.co.uk/?pa…513 and put them in different coloured slots that would work and make it dual channel ?

scott160592;4432624

right just to make sure if i buy these … right just to make sure if i buy these http://www.web-systems.co.uk/?page=Products&pid=4513 and put them in different coloured slots that would work and make it dual channel ?



Yes and both will run at 1066Mhz :thumbsup:

Original Poster

i have just built my pc and brought the 1066mhz ram could someone look at this screenshot and tell me if i am getting 1066mhz or 800mhz out of the ram :thumbsup:

http://i365.photobucket.com/albums/oo91/scotto160592/Untitled.jpg

Thats 800MHz (DDR at 400MHz) at the moment - you probably need to set it to the faster speed in the bios

Original Poster

jah128;4446537

Thats 800MHz (DDR at 400MHz) at the moment - you probably need to set it … Thats 800MHz (DDR at 400MHz) at the moment - you probably need to set it to the faster speed in the bios



ok thanks ill go look in the bios now :thumbsup: rep left for fast reply thanks

Original Poster

iv been in the bios i cant really find anything. could you tell me what to look for ?

Its probably something like Advanced -> Northbridge Configuration -> DRAM Configuration -> Memory Clock Mode. If its set to 'Auto' change to manual and then 1066 (might be listed as 533)

Original Poster

jah128;4446970

Its probably something like Advanced - Northbridge Configuration - DRAM … Its probably something like Advanced -> Northbridge Configuration -> DRAM Configuration -> Memory Clock Mode. If its set to 'Auto' change to manual and then 1066 (might be listed as 533)



brilliant thanks its all done now :thumbsup:

Nice one

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