I can't for the life of me get a stable overclock on my 1090T above 3.7Ghz (200 x 18.5)
I'm running on a 990FXA-UD5. Using the latest bios, the stock core voltage is 1.450v and i have it bumped 1.475v to get the 3.7 stable. HT link is sitting at 2400mhz with stock voltage and everything else is stock (other than the DRAM voltage which is bumped to force factory ratings on the ram im using. The board calls for 1.5v but the ram is rated for 1.65 @ 9 CAS)
I've seen all sorts of different bios settings for stable overclocks up to 4.2ghz. I know that Thuban has problems when it reaches temps of 55C+, and on my CM V6 temps will peak at around 51C on prime95 blend @20 minutes.
Also something worth mentioning is that voltages on my board aren't stable. Seems to be a trend with the UD5 and maybe the UD7 but while idle the cpu will overdraw @ 1.504v and under load actually undervolts to as low as ~1.4v. This to me makes absolutely no sense and leads me to believe that achieving anything above 3.7Ghz isnt in my favor.
Does anybody have any experience with this?
Am i stuck at 3.7Ghz with this motherboard / Cooling solution?
Well on my 1090t i have the same problem once the multiplier goes that high so i run mine at 3.9ghz fsb 300mhz and multiplier 13 it takes 1.48v might be worth a try for you its 100% stable for me but i have a hard time getting 4ghz it takes a lot of voltage
the overdraw of voltage is normal its called load line calibration its to help keep enough voltage to your cpu, you may need to check this is enabled in your bios
what other voltages do you have set? and what is your ram clocked to? I've got the multiplier on mine lowered to keep it at 1600 (1599).
Even with the bus speed raised and the multiplier lowered i still cant get it stable. I'm able to boot just fine but it cant get more than 3 minutes into prime95 blend. Temps are fine.. and i dont see a setting for LLC voltage control or anything like that. only voltages i dont mess with are the CPU PLL Voltage control the NB/PCIe/PLL Voltage control which i leave at the normal settings of 2.5v and 1.8v respectively. In order to get a 1.48v draw under load i had to set CPU Voltage to 1.525v and while idle it peaks at 1.56v.
About your comment referring to the multiplier being happier at a lower setting.. i've seen the 1090t overclocked to 4.2 using the stock bus speed of 200 x 21.. of course they were using a custom water loop but still.. it leads me to believe that the multiplier isnt the cause of the problem im having.
This is driving me crazy, because i know this chip can sit comfortably at higher clocks but it refuses to stay above 3.7 for me.
Is there some sort of noobish oversight I'm making?
"About your comment referring to the multiplier being happier at a lower setting.. i've seen the 1090t overclocked to 4.2 using the stock bus speed of 200 x 21.. of course they were using a custom water loop but still.. it leads me to believe that the multiplier isnt the cause of the problem im having"
yeah i've seen verified overclocks done on multiplier I'm just saying for my chip it didn't like multiplier becoming unstable once raised and I had more success using the fsb even for 3.7ghz I had to use the fsb bringing it too 232x16 but anyhow,
have you disabled cool n' quiet? it could be cpu throttling to keep cool which would explain your voltage drop, although that would depend if that 55c is your core temp or the cpu socket temp
disable C1E and turbo core too if you haven't already
other than this I would think your psu is not much good if you have 1.56v (which is high for the cpu be careful) and its dropping to 1.48 under load, what psu are you using?
your not guarenteed my settings would work for you as like you said some ppl can use the multiplier sucessfully where as I have ever seemed to be
my dram is at 1600mhz @ 1.65v
cpu: 1.48v which draws 1.52v under load
cpu/NB: 1.35v (careful with this one as anything over 1.3v is high)
NB 1.28vcpu vdda: 2.48v
im using 300x13 and 2700 NB frequency and 2100 HT frequency