Gigabyte MA790XT-UD4P DDR voltage

[Prim01]

Hi,

I can't set DDR voltage over 1,8v. 1,8v is the highest voltage where computer boots. If I set 1,85v or higher it doesnt boot bios. Nothing is overclocked. The DDR 3 multiplyer is 6,66. Anyone knows what the problem might be?

Here is the list of my components:

Gigabyte MA790XT-UD4P (F4g)
AMD Phenom II 720BE
Kingston DDR3 HyperX 1600MHz 4GB (9,9,9,27)
Gainward GTS250 1024Mb
Samsung Spinpoint 2x160Gb (Raid0)
Western Digital 500Gb
Antec Phantom Power 500W

[runn3R]

Hi

Is your RAM model KHX12800D3K2/4G (2x 2GB, rated 1.9 V) ?
What is max speed it works with when voltage set to 1.8 V?

As F4G is beta bios, have you tried with F4 bios?

[runn3R]

Here is the latest bios F5b, you may also try with it

[Prim01]

Thanks for getting back to me,

To begin with, I tryed both F4 and F5b version of the bios, and the problem is the same no matter what version I run. The RAM modules are correctly KHX12800D3K2/4G (1,7v - 1,9v; 9,9,9,27)

I tested RAMs with memtest86+ program and come up with following. If I run default settings in bios, that being 200x6,66 and I belive it in auto mode sets 1,6v then the memory test runs without any errors. If i do the same thing (observe it is still 200x6,66)  but with highing up voltage to 1,8v I get error at the 7th testmoment. Ill try to run more tests tomorow with default volts, in order to see how much higher frequency I can obtan. And another set with 1,7v, but for me it seems that there might be two cases. Ither the RAM modules cant tolerate higher voltage, or the motherboards higher DDR voltage is unstable. Am I right or am i missing something?

[Prim01]

Hi again,

Well I've done some more extensive tests and it seems that the highest voltage that I can give RAM modules is 1,7v. At 1,75v errors in memtest are starting to appear. The highest speed that I've been able to obtain is 215x6,66=1432MHz at 1,7v and 9,9,9,24, 1T.

By the way the latest F5b bios gives me problems with so called "cold start" - problems that I didnt have on F4 and F4g versions. Tree out of four times the system won't boot without clearing CMOS, thou it is absolutelly stable otherwise. Restarts are working properly. What are your thoughts on both subjects?

[runn3R]

I have checked and your RAM was not tested by Gigabyte:
http://www.giga-byte.co.uk/FileList/MemorySupport/motherboard_memroy_ga-ma790xt-ud4p.pdf
at all 

As far as I understand your aim is to run this memory with 1600MHz and according to MB's spec it's overclocked then.

Just for checking have you tried to change the multiplier of memory clock from 6,66 into 8 while keeping CPU at 200?

Regarding "cold start" - does it happen also at default settings or only while overclocked?

[Prim01]

To be honest the list of tested by Gigabyte RAM modules is quite short. Most accessible modules in Sweden are Crucial, Kingston, Corsair and OZC. None of those modules volumed 2GB had been tested at DDR 1600.

The aim is, as you rightly mention, to run memory as PC12800 instead of PC10600 and it may be overclocked according to MB's spec but it is still the "normal" voltage with respect to Kingstone specs. And lets face the fact that MA790XT-UD4P is positioned as an overclocking friendly motherboard, with various overclocking features. I am trying to utilize one of this features, namely the possebility of applying higher DDR voltage. The fact that it ain't vorking tells me that something is wrong, ither with the memory modules or with the board. I suspect that if Gigabyte not even highlighting 1,85v with red color (the red is from 1,9v and above), this must mean that it should be a working voltage. My understanding leaning towards that there is no way of telling which is mailfunctioning unless I lay my hands on another set of RAM modules and try to run them on the same board.

(The first thing I did was setting multiplier to 8x200 It boots with voltage up to 1,8 but memtest unstable)

Cold start problem is regardless of overclocked vs. nonoverclocked mode, so I decided to go back to F4 bios that stable in this sence. If you want me to run some tests with F5b bios I will be happy to do so.

[runn3R]

Hi

I suggest you try with different RAM modules, the best would be with some from the list checked & approved by Gigabyte (QVL).

P.S. If you want to check sth interesting with your current RAM you can also do simple test - install just only 1 stick of memory and then see if it works with 1600 MHz.