Why a 1333Hz DDR3 RAM works at 1066Hz on GA-MA770-US3 by default ?

[awpnusp]

To update my old PC, yesterday I bought 3 device below:
CPU: AMD X2 250
RAM: Kinston DDR3 1333mhz 2GB
MB: GA-MA770T-US3 (rev. 1.0)


( All things below is result that I didn't do any overclock )
They looks working fine but one thing: the RAM by default works at 1066MHz instead of 1333MHz that it should do. Here are some snapshots about that:

pic 1
 

pic2
 

pic3
 

pic4


pic5
 

pic6


pic7
 

pic8




As you saw in the 8th picture, by default the Memory Clock is set at "Auto-x5.33-1066Mhz".
I have to manually set it to "Manual-x6.66", then it works at 1333Mhz. Here are some snapshots after setting it to Manual-x6.66:

pic9
 

pic10


pic11




So, why the RAM doesn't work at 1333Mhz by default ? Is it a mistake that choosing DDR3 1333 RAM for AMD X2 250 ?
Any response will be appreciate.

[awpnusp]

By the way, what is the "Ganged" and "Unganged" ?
And why the 9th picture still shows "Ungaged" after I manually set it to "ganged" (and definitely have saved the settings ) in BIOS (see the 6th picture)?

[topdog]

By the way, what is the "Ganged" and "Unganged" ?
And why the 9th picture still shows "Ungaged" after I manually set it to "ganged" (and definitely have saved the settings ) in BIOS (see the 6th picture)?

You need two sticks of RAM to run Ganged or Unganged

If you have two sticks then run it as Unganged

[DarkFoss]

Pic 11 looks good your rams is running at 1333MHz you always multiply CPU-Z's Dram Frequency by 2... 669.7x2=1339.4

As for ganged vs unganged for multitasking and multi-threaded apps unganged is better..if all you do is play games and bench single threaded apps then run ganged google ganged vs unganged and you'll see a long thread at overclockers.com.

[awpnusp]

Thanks a lot. Now, the question about ganged & unganged is clear.
Could anyone tell me the other question in the main post: why the RAM by default work at 1066mhz instead of 1333mhz ?

[DarkFoss]

it could be a safety default feature..my Adata 1600G booted at 1333MHz..I've had some boards that only booted with 1 stick of ram until I went into the bios and manually set the timings and voltage..could also be bios related..in your pics you have the original F1 bios..using a newer or latest bios may fix that.

I don't have that board so I can't say which bios is best for your board..coming from a socket 939/agp board, I'm still feeling my way around this newer tech.

[awpnusp]

Thank you, DarkFoss, I don't notice the bios version.
I'm going to try the latest version.

[xxGriff]

The memory controller on all AMD x64 CPU's is on-die and not on the MoBo.

Your CPU is dictating what the RAM will run at. the Regor (Athlon x2's 250/255/260 etc)  core supports up 1066 DDR3. native support for 1333+ DDR3 will be Deneb/Callisto Cores. you may be able to manually set to faster settings, but i am not certain and a BIOS that allows over ride of the CPU's max, this is unlikely and may cause instability. Callisto is actually a Deneb core with 2 cores disabled...

Ganged vs. Unganged

Ganged mode = 1x128 Bit memory interface, and usually best for single thread performance

Unganged mode = 2x64 bit memory interface and usually best for Multi-thread performance

as does pertain to applications being used. if you only run one app at a time and it requires alot of memory thru-put/bandwidth then ganged mode may be a better choice, but for most users who play games, listen to music and browse ie. multi-task then unganged is a better choice.

[Badbonji]

The motherboard just defaults at 1066MHz, as that is the speed officially supported by the cpu (said above). It ensures that the board will post, just in case any higher speeds cause instability.

RAM doesn't tell the motherboard what speed it should run at, that is just the speed that the RAM has been tested and is rated for. With my motherboard, on a different socket, there is an option to enable the XMP of the RAM. This will run the RAM at the highest rated speed, but you may need to adjust the DRAM voltage still (not too sure about AMD motherboard chipsets, have never owned one).

[Dark Mantis]

And there again whilst XMP is a very useful setting it won't work if you fill all the slots as then you need to manually compensate for the extra loading.

[absic]

You don't get XMP on AMD motherboards! It's an Intel thing I guess.

[Dark Mantis]

Yes it is something that AMD has never picked up on. Although didn't they have some similar type of thing before?

[absic]

AMD uses BEMP, Black Edition Memory Profile(s)