DDR3-1600 works at 1333, fails at 1600

[rrundzans]

Hi, everyone!

 

I have some problems raising my RAMs freq. By spec, ram is tested to work at 800Mhz (ddr3-1600), but unfortunately i cant get there. Frankly i cant get stable when its > 666. Right now my cpu is OCed to 416x8.5, and fsb:dram ratio changed from 1/2 to 5/8, so dram stays at ~666(416 : 5 * 8 = 665.6).

 

My system:

>>> >>> >>>

Kinston DDR3-1600 ( KHX12800D3K2/2G ) RAM x 4

http://dl.dropbox.com/u/846888/01/KHX12800D3K2_2G.pdf

 

Giga Byte GA-EP45T-DS3R MOBO (1600/1333/1066/800 MHz FSB) (Support for DDR3 1900 (O.C.)/1600/1333/1066/800 MHz)

http://www.gigabyte.com.tw/Products/Mother...e=GA-EP45T-DS3R

 

Core2 Quad Q9550 Yorkfield C1

http://processorfinder.intel.com/details.aspx?sSpec=SLAWQ

 

Chieftec 750W PFC Cable Management

Asus Silent Knight II CPU cooler

<<< <<< <<<

 

Right now i got stable overclock (primed & memtested):

http://dl.dropbox.com/u/846888/01/summ.png (hwinfo sys summary)

http://dl.dropbox.com/u/846888/01/01.png (hwinfo mem entry)

http://dl.dropbox.com/u/846888/01/spd.png (cpuz SPD tab)

http://dl.dropbox.com/u/846888/01/mem.png (cpuz MEM tab)

http://dl.dropbox.com/u/846888/01/aaa.png (hwinfo one module (all 4 identic) info #1)

http://dl.dropbox.com/u/846888/01/bbb.png (hwinfo one module info #2)

 

settings @ bios:

http://dl.dropbox.com/u/846888/01/11032010(000).jpg (mit #1)

http://dl.dropbox.com/u/846888/01/11032010(001).jpg (mit #2)

http://dl.dropbox.com/u/846888/01/11032010(002).jpg (mit #3)

http://dl.dropbox.com/u/846888/01/11032010(003).jpg (acc)

http://dl.dropbox.com/u/846888/01/11032010(004).jpg (atc #1)

http://dl.dropbox.com/u/846888/01/11032010(005).jpg (atc #2)

 

I tried a lot of combos to raise rams freq. Common thing was lowering fsb from 416 to 400, and changing fsb:dram freq back to 1:2 (so ram freq becomes 800), setting timings to 9-9-9-27.

 

* The best result (fail `only` at 32-34% in memtest - ran 2 times) settings were: 333 g(mch) freq latch, 1.9V, 1:2 ratio.

* When i used 400 latch, it failed more often then when 333 was used (if i remember correctly, 444 mch, 1.9V, 1:2 failed @ 3-5% in memtest).

* If i lowered voltages to [1.7-1.8], i couldnt even post.

 

Any suggestions how to solve this issue? Currently i am out of ideas . Mybe i have to change cpu/mch clock skews? Or other voltages like ram termination?

 

Any help will be appreciated!

Tnx in advance

Edited March 11, 2010 by rrundzans

[nanoprobe]

If the standard voltage for that ram is 1.5v than IMHO running it at 1.9v is too high. Have you tried running it a lower voltage?

[cirro]

try running your system at stock settings (load bios defaults) and see how your ram reacts, then gradually increase OC again (yes settings may need to be changed)

 

or get it to a stable speed and runmemtest

 

it can't hurt to run memtest anyways,especially when out of box having problems with ram

[rrundzans]

I know it feels a bit weird to test ram in such a wide range (1.5-1.9), but, as spec says, 1600 is supposed to work @1.7-1.9, and JEDEC standarts are supposed to work @1.5.

Edited March 12, 2010 by rrundzans

[Waco]

Bring your CPU back to stock, set the ram speed appropriately (check it's stability at various speeds), then bring your OC back up.