Stabilizing 4x 2GiB on P45

[rrundzans]

Hi, everyone

 

I will start with little bit of specs:

** 2x KHX1800C9D3K2/4G = 4 sticks DDR3 1800 MT/s 1.7-1.9V

** GA-EP45T-DS3R ( P45 ) - advertises that it can work with 1900MT/s ddr3

 

Thing about those modules is that they work perfeclty @1.5 JEDEC (as hardcoded in SPD), but if u want to get to 1800MT/s, u need smth in between 1.7-1.9.

 

So, at start, i had only one 1800 kit (2 sticks), all i done was incresing volts to 1.72, it was perfectly stable (8hrs prime + 8h memtest) and i was able to reach those 1800MT/s with no probs. But when i add another kit to equasion, i had to lower voltage to 1.5 JEDEC just to make it stable at stock 1333. Its quite stable at 1333 1.8v, but fails at prime in like 1hour.

 

So - 4 sticks, all at stock except dram voltage. When 1.5v its stable. when >1.7 its not. Does that means cause of failure is temperature related? Those sticks are with heatspreaders, so they are fat, and slots are quite close to each other, so there are almost no gap between modules. Or u suggest me continue trying and adjusting other voltages as well? I guess it is not timing related, because at 1.5 it works just fine. Mybe it would be good to unset auto property for other ram related voltages (like termination and reference voltages)? Auto worked fine with 2 modules..

 

Let me know what do you think . Tnx in advance.

[ARandomOWL]

You may need some extra NB voltage. Try 1.3 to 1.35v and see if it makes a difference.

[rrundzans]

You may need some extra NB voltage. Try 1.3 to 1.35v and see if it makes a difference.

 

eee, but is there reason why i was able to leave NB volts at stock (1.1 if i remember correctly) and it worked with 4 sticks @ 1.5 ? But anyways tnx 4 advice, will try pumping some juice to nb

 

p.s.

hah, anyways, i have to admit, i am kind a lazy bastard, only one of those kits i really tested on voltage >1.7. I kind a assumed that other one will be the same, mainly because 1.7-1.9 V is mentioned in specs. I guess i will test both pairs independently again, and post the results here asap.

Edited September 23, 2010 by rrundzans

[rrundzans]

So i finally checked second kit too. One of those kits was allready tested in red slots (DC symetric mode), clocked perfectly above 1600MT/s using 1.72 dram core voltage @bios (vdrooped to 1.68-1.70, as monitored in HWMonitor). So i finally defeated my laziness and tested my 2nd kit.

 

Modules of this kit i put in green slots, just to make sure my problems are not related with defective slots etc. This kit clocked to 1600MT/s with no problems, just like my other kit.

 

CPU and MCH voltages were left to default - fixed them manually - 1.2375 cpu; 1.1 mch; 1.5pll; etc - stock P45 settings as u can see.

 

I changed DRAM voltage to 1.72. As stated in dram spec, clocking to 1800MT/s is possible in voltage range [1.7-1.9]. If there's no 1.72 or above, raising dram speed is impossible on those modules.

 

I also changed DRAM termination, ChA/B reference and MCH/DRAM Ref voltages (all of them) to 0.78 at bios(reported 0.69 at easyTune6). At stock all those voltages were auto @ bios and 0.75 at easytune. I have to admit i dunno why, but with 0.75V system is not stable when 1.72 dram votage are used. I kind a guessed this 0.78/0.69 value.

 

With those settings i was able to raise fsb to 400 and therefore run RAM(each kit indepenantly) @ 1600MT/s. But when i put all my modules in, i cant get my system stable when using 1.72 dram voltage or above, no matter what i change. When 1.5 JEDEC voltage are used, no problems, system stable while stressing 6hrs with prime blend (stock P45 settings used, 1.5 dram voltage and 0.75 termination/chA-chB addr ref etc).

 

So there is actually 2 questions. Why those DRAM termination/ChA reference/ChB reference/ MCH/DRAM reference voltages affects stability? What are their purpose exactly? Cant find anything clear on web. And of course - any advices how to put those 4 modules on 1.72 and maintain stability?

Edited September 27, 2010 by rrundzans

[MrAlex]

Just a heads up, it's GB, not GiB. GiB is Gibibyte.

[rrundzans]

This GB vs GiB is quite spippery subject. Just like holly wars.

 

http://en.wikipedia.org/wiki/Binary_prefix

while new terms such as kibibyte, mebibyte and gibibyte, abbreviated KiB, MiB, and GiB, would denote 1024 bytes, 1048576 bytes, and 1073741824 bytes respectively

[MrAlex]

This GB vs GiB is quite spippery subject. Just like holly wars.

 

http://en.wikipedia....i/Binary_prefix

 

 

So they've updated it now? So a Gigabyte is now 1000 Megabytes? Interesting...

[MercuryDoun]

With 4 sticks at 1333, your stock NB voltage would be fine... But trying to bump 4 sticks to 1800 makes a whole world of difference. You need more power to handle the much increased data transfer rate.

[rrundzans]

With 4 sticks at 1333, your stock NB voltage would be fine... But trying to bump 4 sticks to 1800 makes a whole world of difference. You need more power to handle the much increased data transfer rate.

 

Problem is, i didn't even tried raising RAM speed to 1800 MT/s. I am trying to "OC" (not real OC, because 1800 is within specs) with those 4sticks by performing 2 simple steps, just like i done with 2stick config:

1. Getting DRAM voltage to >1.70, while leaving standard module speed (stock fsb) - 1333 MT/s. Those modules, by triple-both my experience, specs and reviews@net, can achieve rated speed only on voltages 1.7-1.9. When i used one kit, it was definately clear, that 1.72 voltage for each module are enough to reach 1800.

2. Raising FSB till hitting 1800 MT/s DRAM speed.

 

I am failing at step one, i am not even @2nd one. I am using stock DRAM speed (1333), but when i just incerese DRAM voltage, it becomes unstable. Why? I have strong feeling its eather heat (modules ar close to each other) or something with those voodo-like voltages, that helped me get my 2stick system stable: dram termination, channel a addr and data reference, channel b addr and data reference and mch/dram reference voltages. This time guessing kind a fails.

Edited September 27, 2010 by rrundzans

[RJR]

Running with all slots populated is fun some times, some motherboards just don't like to play nice.

 

I'm presuming you have set your Performance Enhance to Standard from the default Turbo setting. If not, this will loosen up some of your sub-timings and sometimes even your main timings too.

You can also manually loosen up your main timings to see if that helps.

I'll be another one too, bump up your mch voltage.

 

Heat wise, it would have to get up to 85c-90c to really cause problems, so too hot to touch, easiest way to find out, stick your hand in there and give them a touch.

[rrundzans]

Running with all slots populated is fun some times, some motherboards just don't like to play nice.

 

I'm presuming you have set your Performance Enhance to Standard from the default Turbo setting. If not, this will loosen up some of your sub-timings and sometimes even your main timings too.

You can also manually loosen up your main timings to see if that helps.

I'll be another one too, bump up your mch voltage.

 

Heat wise, it would have to get up to 85c-90c to really cause problems, so too hot to touch, easiest way to find out, stick your hand in there and give them a touch.

 

Sorry, i forgot to mention - perf enchance is allready set to std. Yesterday i tried raising MCH core voltage to 1.3 (i guess thats quite high, at stock its only 1.1), but without success. Anyways, i just cant understand why it works with 1.5 JEDEC voltage, but fails in notime, when changing to 1.72 or more (using same voltages for dram-termination,chA reference etc which made 1kit stable . And no "auto" option were used in ram-related options).

Edited September 27, 2010 by rrundzans

[RJR]

Sorry, i forgot to mention - perf enchance is allready set to std. Yesterday i tried raising MCH core voltage to 1.3 (i guess thats quite high, at stock its only 1.1), but without success. Anyways, i just cant understand why it works with 1.5 JEDEC voltage, but fails in notime, when changing to 1.72 or more (using same voltages for dram-termination,chA reference etc which made 1kit stable . And no "auto" option were used in ram-related options).

See how far 1.5v will allow the Ram to go, then slowly raise the voltage (1.55v then 1.6v, etc.) and ram frequency, then when it gets stuck up the Mch voltage and/or loosen timings, rinse and repeat. I had one set that I had to up 1 Bclk at a time, even jumping 5 at a time it didn't like it.

 

It's just very time consuming and sometimes very frustrating, if you give it the time I'm sure it will work out for you.