using 4 dimms won't allow DDR2 1066 on AM2+ ?

[jordanl17]

check this quote from a Gigabyte Qualified memory Vedor list: "Note: Due to AMD AM2+ CPU limitation, DD2 1066 is only supported by 1 dimm per channel."

holy crap, is this true? I just ordered a system (Phenom II 920) amd 780chipset, w/ 2 1gb sticks of 1066 memory... and I just now wanted to order 2 more 1gb sticks to give me 4gb, so I could better utilize 64bit Vista.

BUT... will I be limited to 800Mhz because I'm using 4 dimms??!?! If so, I will return all 4 sticks and just get 2 2gb sticks... what a pain in the ass!!!

so, question is: is Gigabyte's warning true?

 

[cm123]

I have Asus M3A32-MVP Deluxe and AMD PII X4 940 - 4 sticks of Mushkin Accent DDR2-1066MHz running with no issues...

This although has the AMD 790FX chipset - will say, as far as benchmarking goes, was slightly slower with 4 dimms, in real life in Vista 64, seems much faster with 8GB (4 dimms) for whatever reason...

 

[Yellowbeard]

2 x 2GB is the best setup on AMD these days. Perhaps your vendor will allow you to exchange to a 2 x 2GB kit?

And, that spec you quoted is only the "officially" tested spec. And cm123 noted, you may be able to exceed that.

 

[Yellowbeard]

As far as being limited to DDR800, that will depend on how good the memory controller is on your individual CPU, not the MOBO.

 

[jordanl17]

update: I just ordered G.SKILL 2x2gb 240-Pin DDR2 SDRAM DDR2 1066. I ordered the 4 x 1gb 1066 from Newegg, I'm sure they will let me RMA it...

 

[tcsenter]

AMD's specification provides for a maximum of one DIMM per channel @ DDR2-1066. On a board with four memory sockets capable of dual channel operation, that means a maximum of two DIMMs. However, this is just an upper limit defined by AMD to ensure a relatively high degree of stability and reliability. It is not the maximum 'theoretical' limit.

Different motherboards and modules will be more or less capable of exceeding this practical limit. Even a well-designed motherboard is going to show variability with different memory modules, and vice versa. Its essentially overclocking.

Memory module operating parameters are specified or advertised according to the product configured as it is packaged and sold. IOW, if you purchase a two module kit, the parameters specified were tested and approved only for a two module configuration, not three modules or four modules. If you purchase two kits of two modules, the tested configuration is still two modules. So if the two module DDR2-1066 kit advertises 5-5-5-15 @ 2.1V (or whatever), this is no longer valid for three or four modules.

 

[cm123]

Originally posted by: cm123
I have Asus M3A32-MVP Deluxe and AMD PII X4 940 - 4 sticks of Mushkin Accent DDR2-1066MHz running with no issues...

This although has the AMD 790FX chipset - will say, as far as benchmarking goes, was slightly slower with 4 dimms, in real life in Vista 64, seems much faster with 8GB (4 dimms) for whatever reason...

should of added in this post - odd thing for my system is that if I run the memory at ddr2-800MHz, while bench marks put it ever so slight behind ddr2-1066mhz, its not the case though when I run game demo/frame-rate tests, about 2 to 5 % faster (last time I did them) running at ddr2-800mhz speeds, so go figure...

I'm not certain is makes much diff in real work -