Samsung Green DDR3 Problem

Hi all, needing some advice for a long standing issue with my RAM and PC.


Originally I had 2x4gb Samsung DDR3 RAM, that I ran for ages, no problem, I then bought another 2x4gb pair to use in conjunction.
Now when all 4 modules are installed, the system will either
1. Not start up and report a memory problem through the debug LED
2. Start up and boot to windows 50% of the time, the other 50% it will stay on a blank screen, no bios boot screen and a few hits of the reset button is needed to get a windows boot.

Which of these two scenario occurs depends on the configuration of the ram sticks in the dual channel slots, and it is often a case of me moving the sticks about randomly until I end up with scenario 2 (the 'best case').

Now I never had this problem with my original 2x4gb sticks, and the problem doesn't occur with the other pair I bought when it is installed as 2x4gb. The motherboard was also upgraded but this didn't solve the problem.

It's lead me to conclude that there seems to be a problem running the Samsung Ram in 4x4gb configuration, and swapping the modules between slots either stops the PC from starting completely, or makes it start up about 50% of the time.

Currently I'm just running 2x4gb because I want that predictability to know my PC will start up first time, every time, but just want to know if anyone has had a similar problem or is this just a side effect of a 4x4gb setup with two different pairings of RAM?

What happens if you give the ram 1.5v?

I have been running 4x 4Gb sticks of Samsung Green with no problems for years and they have always been overclocked and had the timings tightened up. I have had them in my old socket 1156 Asus P55/i5 760 setup and my current Haswell setup and the only difference is that on the old 1156 setup I had to increase the memory controller voltage a step or two to be able to run all 4 sticks. I suspect that this is your problem. Not sure what it will be called on your board but look for something along the lines of VTT voltage (VCCIO). It couls also be called IMC, QPI/Dram or QPI/VTT. Increase it a to the next step or two up and test. Hopefully that should get you working with all sticks.

Well pastymuncher that might have just fixed it! Took the VTT from 1.05 to 1.1v, maybe a bit overkill but that seems to have stabilised the system and it's now starting, first time, everytime! Will test out the next few days but thanks so much!

Was going to suggest the same. I've run 4x4GB of Sammy Gs previously too.

Michael_10 said:

Well pastymuncher that might have just fixed it! Took the VTT from 1.05 to 1.1v, maybe a bit overkill but that seems to have stabilised the system and it's now starting, first time, everytime! Will test out the next few days but thanks so much!

Click to expand...

Excellent news. We used to have to do it all the time in the socket 775 days but I didn't have to touch anything on my current Haswell board to get 4x sticks working.

Have you got them overclocked yet? Mine have always run at 2133mhz 9-10-10-21-1T with most of the seconds and thirds tightened up as well with 1.5v. OCUK found that they could do the following in their testing:-

1600MHz (7-8-8-24 1N) @ 1.40v
1866MHz (9-9-9-27 1N) @ 1.40v
2000MHz (9-10-10-28 1N) @ 1.45v
2133MHz (10-10-10-28 1N) @ 1.45v
2400MHz (11-11-11-28 2N) @ 1.50v

Even if you don't want to overclock them you can tighten the timings up as I believe they run at cas 11 at stock. I have a set in the wifes pc running at 1600mhz (H81 motherboard) 7-7-8-21-1T @ 1.4v.

pastymuncher said:

Excellent news. We used to have to do it all the time in the socket 775 days but I didn't have to touch anything on my current Haswell board to get 4x sticks working.

Have you got them overclocked yet? Mine have always run at 2133mhz 9-10-10-21-1T with most of the seconds and thirds tightened up as well with 1.5v. OCUK found that they could do the following in their testing:-

1600MHz (7-8-8-24 1N) @ 1.40v
1866MHz (9-9-9-27 1N) @ 1.40v
2000MHz (9-10-10-28 1N) @ 1.45v
2133MHz (10-10-10-28 1N) @ 1.45v
2400MHz (11-11-11-28 2N) @ 1.50v

Even if you don't want to overclock them you can tighten the timings up as I believe they run at cas 11 at stock. I have a set in the wifes pc running at 1600mhz (H81 motherboard) 7-7-8-21-1T @ 1.4v.

Click to expand...

Just set the ram to the 1866MHz profile and looking good! Will experiment wit hthe other profiles once I'm sure everything is stable. For general use and gaming how much of an improvement does a ram overclock give usually?

Probably not a lot and not that noticeable apart from in benchmarks but I like to get the most I can out of my system. There is a comparison here between 1600, 1866, 2133 and 2400mhz DDR3. There isn't much of a gain in the max fps with the game benchmarks but take a look at the boost in the minimum fps. One thing to take into account is that the Samsung Green can do 2133mhz at the timings that most ram only does 1600mhz at so that will give a bit of a performance boost as well.

pastymuncher said:

Probably not a lot and not that noticeable apart from in benchmarks but I like to get the most I can out of my system. There is a comparison here between 1600, 1866, 2133 and 2400mhz DDR3. There isn't much of a gain in the max fps with the game benchmarks but take a look at the boost in the minimum fps. One thing to take into account is that the Samsung Green can do 2133mhz at the timings that most ram only does 1600mhz at so that will give a bit of a performance boost as well.

Click to expand...

Just set my RAM to the 2133MHz profile, didn't have an option to increase to 2400MHz so I think it's not supported on my motherboard.

Interesting read and good to know that there is some increase in performance, thanks for all your help pastymuncher!

You lose some performance with 2400mhz as it runs at 2T compared to 1T with 2133mhz. That is why I stuck with 2133mhz plus I reckon that with all the other timing tweaks I have made it's faster than 2400mhz anyway.

I ran 4x4GB sticks at 2000mhz for years, coupled with i5-3570k at 4.2GHz. I couldn't quite get the stability at 2133mhz to make it worth it. However, when I pushed my CPU to 4.5GHz, I would get the occasional BSOD that wouldn't go away until I dropped my RAM speed to 1866mhz.

I used the OCUK timings, always have.

Might have spoken too soon, started having problems when my PC sleeps for 5-6 hours, I get a blank screen and no input when I resume and I need to hit the reset switch. I've taken the RAM speeds back to stock, and VTT is set to 1.5 and I've also increase IMC a little bit too. Any ideas?

Sorry, no idea on that one. If my pc isn't being used then it's shut down and turned off at the wall.

you probably need more vvcio..
my 2500k needs 1.16v vccio for 4x4gb single sided samsung @1866 9-10-10-28-1