Getting 12 GB DDR3 to run at full speed

[click4dylan]

I previously purchased this kit of ram in early 2010: http://www.newegg.com/Product/Product.aspx?Item=N82E16820211409

Then about 4 months ago i purchased this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16820211457


so now i have a total of 12 GB which are running in dual channel. the problem is, I used to be able to run the 4 GB kit at 1600mhz at 8-8-8-20-25-1T timings just fine with no stability issues. After adding the extra 8 GB (all 4 slots are filled), they won't run at 1600mhz even at stock timings 9-9-24 with 2T. I've fiddled with the northbridge frequency and memory voltage but no matter what I do, I still get constant bsod's or lockups. Currently the last 4 months I've been running them at 1333mhz at 7-7-6-18-33-1T without issues but I would really like to try and get them at the rated speed again. I definitely noticed smoother frame rates (less jerky) in games at the higher bandwidth. I also have a fan blowing on the ram chips but that didn't fix the problem either. I'm running a phenom 2 955 C3 at 3.4 GHz at 1.275Vcore with the stock cooler with no issues with that (stock voltage makes it run at 65C, so I had to decrease the vcore a lot)

My current specs are:

phenom 2 955 be c3 @ 3.4ghz 1.275V
Asus m4a89gtd pro
zotac geforce gtx 560 ti amp! edition
auzentech prelude 7.1
750GB seagate+320 GB seagate in raid 0
coolermaster haf 932
windows server 2008 r2

ps: how much difference is there in 1T vs 2T. also, my bios has the option to change CPU/NB voltage, NB Voltage, and NB 1.8 Voltage, SB voltage, along with VCORE. not sure which ones to change

 

[EarthDog]

Memory controller on AMD isnt that great... you are adding more stress to it with more sticks/quantity of ram. Try adding a bit of NB voltage and see if that helps. You shouldnt be noticing a difference in 1333 CL7 vs 1600Mhz CL9 as that is around the same speed.

 

[click4dylan]

can you be exact with voltage, is it CPU/NB voltage, NB Voltage, or NB 1.8? also which should i set the command rate at, 1T or 2T? thank you!

 

[redduc900]

With the DRAM frequency at DDR3-1600 (200MHz HT Ref. clock x 8 Mem. clock), adjust the DRAM voltage to 1.75V, timings to 9-9-9-24-2T (all sub-timings on Auto), CPU-NB Frequency to 2400MHz (or 2000MHz if not raising the CPU-NB Voltage), CPU-NB Voltage to 1.20-1.30V (possibly higher w/ 12GB of RAM installed), and NB Voltage to ~1.35-1.40V (default is ~1.28V). HT Voltage may also need to bumped to ~1.30V (default is 1.20V). Leave NB 1.8V Voltage at the default of 1.80V.

 

[click4dylan]

Thanks so much, really informative. never thought I'd have to bump the voltages up so much just to get 4 sticks working. I was working in like 0.05v increments before. is there a noticable difference in 1T vs 2T?

 

[shata]

Check into this thread I just made, Same deal... Its crazy manufacture is claiming 1.65v when thats not even close to what it takes to get stable. My corsair took 2.05v

http://www.overclockers.com/forums/showthread.php?t=686438

 

[EarthDog]

Yeah.... I certainly wouldnt follow the advice in that thread ^^... 2.05v will KILL THAT RAM.

 

[shata]

Yeah.... I certainly wouldnt follow the advice in that thread ^^... 2.05v will KILL THAT RAM.

Ya he is right...Thought it was same problem. Stuff probably instantly fry.

 

[click4dylan]

i pretty much gave up trying to get it stable at 1600mhz, no matter what i did it would fail memtest and prime95 within minutes. 1333@7-7-6-18-33-1T works flawlessly on stock voltages. guess thats what ill stick with. thanks anyway guys