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Phenom 2 AM3 DDR3 memory problem found...

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February 13, 2009 5:25:04 AM

http://www.fudzilla.com/index.php?option=com_content&ta...

Anyone else know anything about this? If it's true or what the detail's are?...Hopefully its nothing bad..lol AMD just cant seem to get a break.
February 13, 2009 7:45:51 AM

i read that they had problems with running lower quality modules on four banks

quote:
***I spoke with Damon Muzny at AMD about this and it is not actually a problem. This behavoir is actually by design. The reason is that AMD could not predict the behavoir off all DDR3-1333 memory. They found that with certain lower quality memory modules and all four slots populated (2 modules per channel) they encountered instability. They were faced with a choice; either they could drop listing support for DDR3 - 1333 or they could design the system to down clock the memory to 1066 and recommend it to everyone using 2 modules per channel.

You have probably guessesd what they chose.

In all honesty you can usually get more performance from a lower clock and tighter latency than a high clock and loose latency. Or you could always bump up the memory voltage and bring stability back that way.
***

i also seen a thread on other forum, where guy has actually got 8gigs(4modules) of ddr3 1600
http://forums.guru3d.com/showthread.php?p=3027388
seems it worx, but overall it just might be the same thing like with ddr2 1066, setting manually in bios, unganged mode with 2T
February 13, 2009 12:57:49 PM

There's nothing a new stepping can't fix!
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February 13, 2009 4:43:59 PM

Haven't we always known that using more than 1 DIMM per channel could be an issue? It *never* works as well, that's why we buy 2x2Gb packs instead of 4x1Gb.

Seems pretty minor to me, anyway.
February 13, 2009 4:49:08 PM

According to AMD, its only a bug of the software nature. It can be fixed with a BIOS update.
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February 13, 2009 4:59:10 PM

yomamafor1 said:
According to AMD, its only a bug of the software nature. It can be fixed with a BIOS update.


I agree. Although some of the fans over at AMDZoo are complaining it gives AMD a mild black eye, which they can't afford after the TLB disaster on Barcie :)  At least the fanbois got their comeuppance after alleging TLB bugs in i7 over there, long after it was disproved everywhere else :) 
February 14, 2009 9:33:57 PM

Doesn't 1 dimm per channel mean no dual channel action. Don't you have to use 2 sticks per channel for dual channel right?
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February 14, 2009 9:38:58 PM

yomamafor1 said:
According to AMD, its only a bug of the software nature. It can be fixed with a BIOS update.



Havent we heard that one before :ouch: 
February 14, 2009 10:12:02 PM

wingmaster said:
Doesn't 1 dimm per channel mean no dual channel action. Don't you have to use 2 sticks per channel for dual channel right?


No. You use the same amount and number of sticks in both channels. Hence, two equal channels.
February 14, 2009 11:26:49 PM

Hellboy said:
Havent we heard that one before :ouch: 


I actually believe it this time though. The original Phenom's were quite picky about what DDR2-1066 modules they would actually let run at 1066 speeds. If you check around the various forums you will find them to be littered with people complaining that their more expensive 1066 modules were being downclocked to 800. Furthermore, if you check the supported memory list for most AM2+ motherboards you will find that the number of 1066 modules that are officially supported is quite small, while the list of 1066 modules that are supported by "downgrade to 800MHz" is quite large. We are likely just going to see the same thing played out with DDR3 modules this time.
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a b } Memory
February 15, 2009 1:50:05 AM

Just the normal. Most mobos cannot take all 4 of a certain speed DIMM. My mobo is not supposed to run with all 4 slots filled with DDR2 1066 but it does probably due to a mobo update.

Not that big of an issue since DDR31066 is pretty fast anyways.
March 8, 2009 10:30:48 PM

wingmaster said:
Doesn't 1 dimm per channel mean no dual channel action. Don't you have to use 2 sticks per channel for dual channel right?


yes. using 1 dimm per channel puts you in single channel mode.

~D~
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a b } Memory
March 8, 2009 11:20:03 PM

Drummer1976 said:
yes. using 1 dimm per channel puts you in single channel mode.

~D~


Nope. 1 dimm per channel means 1 dimm per channel. If you have 1 dimm per channel and 2 channels, you have 2 dimms total and 2 channels, putting you in dual channel mode.
March 9, 2009 5:46:45 PM

cjl said:
Nope. 1 dimm per channel means 1 dimm per channel. If you have 1 dimm per channel and 2 channels, you have 2 dimms total and 2 channels, putting you in dual channel mode.


why is it then that when i put both dimms in the same colored slot (channel 1 on my board i presume?) that i get dual channel mode, but if i go one in each colored slot (one white, one blue) i get single channel? Im fairly new at this, so im prolly missing something...


~D~
March 9, 2009 7:35:40 PM

You'd have to check the manual for your mobo. Some are like yours, (Dimm 1 and 2 = dual channel) some are Dimm 1 and 3 = dual channel. Slot colours are just colours - no standardized meaning. (other than green means go, red means stop, yellow snow means "don't eat")
March 9, 2009 7:58:26 PM

Drummer1976 said:
why is it then that when i put both dimms in the same colored slot (channel 1 on my board i presume?) that i get dual channel mode, but if i go one in each colored slot (one white, one blue) i get single channel? Im fairly new at this, so im prolly missing something...


~D~

Think of it this way. using the white slots, botyh of them, its both channels, and to be used first, then the blue for more ram. Instead of 1 color per channel, they used 1 color for both channels
March 10, 2009 5:55:29 AM

ahh i see... i assumed a channel was all one color... oops
January 26, 2010 12:26:39 AM

LumberWagon said:
You'd have to check the manual for your mobo. Some are like yours, (Dimm 1 and 2 = dual channel) some are Dimm 1 and 3 = dual channel. Slot colours are just colours - no standardized meaning. (other than green means go, red means stop, yellow snow means "don't eat")

lol
February 21, 2010 1:11:09 PM

well , i have am3 and ddr 3, the memory work only in single channel ... that sucks . in dual channel i have bsod in high frecvency even 1056 at amd recomnadation , my advise get intel , my next computer will be an intel for sure amd go down :pfff:  , All bullshit that talk about that ddr3 1333 configurations with 2 DIMMs per channel experience unrelaible operation is ver true and that REALY means THAT AM3 DOES NOT SUPPORT DUAL CHANNEL so do not make the same mistake as me to buy this fake amd bullshit
May 15, 2011 10:02:41 PM

I have had a similar problem with both a new gigabyte board and the M4A87TD EVO I bought instead because motherboards with just one PS2 socket wont work through a PS2 KVM

If I put any of the three pairs of DDR3 Ram into either motherboard with my X3 450 the machine will either hang or BSOD within 5-30 minutes of switching on even though all system temps are icey cold

Take the second DIMM out and just leave any 1 DIMM of any of the three sets I have and either machine works perfectly

Even downgrading the ram speed doesnt seem to cure the problem, but with just one installed I can up the ram speed and it still runs flawlessly so atm I'm a bit baffled by it as the gigabyte biard isnt even an 870 series board its the MA78LMT-US2H

I have just bought an X2 250 so I also now have a spare AM3 CPU to swap around to try and find out what exactly is causing the problem here as it seems unlikely that two mobos or three sets of DIMMs could all have the exact same fault/incompatibility. But not having another AM3 chip at hand I couldnt do a logical comparison

Not being a power user or gamer it means that at a push I could happily get by with only having one DIMM in each of the two machines I am building

But it would need to be a 2GB DIMM which means the 2x CSX Diablo 1GB 2000Mhz ram I bought are going to be pretty useless lol
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