F3-12800CL9-4GBSR 16GBSR Kit timings, AMD platform

[Gratton]

Motherboard: ASRock M3A785GXH/128M (Crossfire Sideport disabled)
CPU: AMD 975 BE
F3-12800CL9-4GBSR, 4 stick -16GBSR Dual Channel Kit

Problem: Random BSOD's, infrequent, but bothersome

These replaced a pair of Dual Channel 4G kits, F3-12800CL9-4GBNQ. The latter ran at 1066, and auto settings in BIOS, no problems, any basic (set memory speed in BIOS, auto settings) resulted in BSOD's loading Win 7 64-bit. Upgraded to the installed set, and set the speed to 1600 (800) in the BIOS, and kept auto settings.

Using CPU-Z to check things, I see that the memory is running at 1600, however, there appears to be some difference in what is being shown as actual, and the settings shown in SPD.

Seen: 8,8,8,23,32,2T
SPD: 9,9,9,25,33,2T (Note, this shows in CPU-Z as XMP-1600)

While I am comfortable with making manual changes in BIOS, I don't really have any real desire to overclock things in the process, as this is my main daily driver. I tend to build things with the performance in mind that I desire, coupled with long-term reliability, with cooling and ventilation adequate to the task.

Off the top of my uninformed head, the timings I am seeing look more in line with 1333 settings, and unless I miss my guess, those timings look a tad tight for 1600. If they can be achieved, great, so long as things are stable while in use. I'd prefer not having to resort to overclocking/volting. Chipset cooling on this particular motherboard leave a wee bit lacking in cooling, to my tastes, at least.

Any suggestions, kicks in the direction of existing solutions/recommendations, or the like, would be greatly appreciated.

[Tradesman]

If shown in CPU-Z, in the Memory tab as running 1600 (800) at 8,8,8,23, then yes, that may be causing the problems, should be 9-9-9-25. and is this a single set or 2 or more packages? Can try with the 9-9-9-25, if still problems make sure CR (Command Rate/Timing) is 2N or 2T and might want to raise CPU/NB voltage + 0.075 and possibly add + 0.05 to DRAM voltage

[Gratton]

Thanks, that confirms my initial suspicion was at least on the right track. The memory installed did come as a set of four sticks, 4 x 4G for a 16G dual channel kit.

I should be able to manually set 9,9,25 without problems, those settings I recall seeing in the BIOS. Should I bump tRC from 32 to 33 as well? Command Timing is at 2T with either the SPD or memory tab in CPU-Z.

I can't honestly say that I am able to adjust the voltages mentioned, as I haven't looked into things that far. From my recollection, there are at least voltages shown that you mentioned, so one can hope they can be adjusted within BIOS as well. While I am pretty sure they can be tweaked using the AMD Overdrive app, I'd rather do this on a BIOS level, as I've heard that once the OS (Win7, 64-bit) is loaded, tweaking things can at times have less than desirable results.

I am presuming that the DRAM increase is to offset the fact that I am loading all 4 slots on the motherboard as opposed to only using 2 of them? And that the other increases are to boost the memory controller for the same reasons? I can't see any problems with additional heat from the DRAM increase, more than adequate passive cooling on the sticks, and substantial airflow over them as well. The CPU/NB increase give me a wee bit of concern, however. The CPU shouldn't be any issue, as I don't overclock it, and at present, it's cooled with a Corsair H100 with quad 120s in a push pull configuration, it should be more than up the the task of any additional heat created there, but the chipset cooling on the motherboard is a simple passive finned sink setup. While I do have some pretty decent cooling in place, the simplicity of the chipset heatsinks leads me to think they may not be adequate for increasing the heat with added voltage, and the lack of airflow over them from a HSF might help make things more marginal with regards to cooling. These are two separate adjustments, correct?

Truth be known, I may well be in the market for a motherboard upgrade anyway... Figuring out how to get approval from the "finance committee" might take a bit of effort. :-)

Many thanks for the prompt and courteous reply, as well as for the insights, much appreciated!

[Tradesman]

The additional voltages are normally required on AMD platforms as they have week MCs (Memory Controllers). The most powerful CPUs that AMD have out the FX line at it's best is rated to only 2 sticks of 1866...they've made progress with their APUs that can normally run up to 4 sticks of 1866 or even 2133, but most have problems with getting 965 (C) and 975 to carry 4 sticks of 1600. Here's a chart of AMD's making:

http://support.amd.com/PublishingIma...mory-table.png

[Gratton]

I'd heard rumors about the weak MC's, yes, but didn't realize it was so prevalent. Had a 955BE for a time, with C2 stepping, and it was impossible to get running any faster than 1066, wouldn't even load the OS without BSOD's. I'd hoped that with the 975, this had been remedied, but as it is an older CPU now, one would guess that more emphasis is being placed on newer architectures.

At any rate, I've set things manually for 1600 with 9,9,9,25,33,2T, and haven't tinkered with voltages just yet, waiting to see how this does. With the defaults set as they were, the crashes were few and far between, so perhaps adjusting the timings will do the trick. If not, I'll attempt to make the increases mentioned. Just to be clear, I would need to increase both CPU and NB voltages by .075, and DRAM by .05, correct?

[Tradesman]

The DRAM yes, and the CPU/NB or just NB - hopefully not the CPU (vCore) voltage itself - it's the NB or more often labeled CPU/NB that supplies voltage to the MC (Memory Controller)

[Gratton]

By unlocking a couple of areas in BIOS, I can manually set both the DRAM and NB voltages if need be. According to Overdrive, DRAM is presently at 1.480, which is the lowest setting listed manually. It increments in .05V steps, with the next being 1.530,then 1.580 and so forth upwards of 1.7. I'd be hesitant to go past 1.580, with 1.530 as the next step there. It seems that the auto setting is 1.480.

NB is shown as 1.1000 and can be incremented in .0125V steps, so I'd want to shoot for 1.1750 on that setting, perhaps .0250, then .0500, and as a last resort, .0750. This voltage shows as being selected as opposed to auto once multiplier/voltage is set to manual.

My primary interest is stability in the long run, so I only want to make increases to voltages as needed for that end. While I plan to upgrade to a more capable motherboard, in the meantime, logic dictates that I attempt to keep the smoke contained in this one.

Thanks again, in case I hadn't mentioned it, for the input and guidance. Yet another reason that I keep using GSkill products, and suggest them to others in the market.

[Tradesman]

Might just want to kick to 1.2 on NB, 1.58 on DRAM and ensure that is stable. Then take the NB down a notch or two, if still stable drop the DRAM a notch, still good, then drop the NB again....etc and so on - DRAM is perfectly safe to 1.6 and a little higher, NB is the voltage that will produce heat, so want it as low as possible and can play with DRAM voltage to help stabilize

[Gratton]

I'll keep that in mind,and thanks for the tip on DRAM, good to know the headroom is there should that need arise.

Yep, the increase in temps from NB increases gives me a wee bit of concern, considering again the passive cooling implemented on this board. While the case is more than adequately ventilated, it's deeper than some, and sort of moves the motherboard inward from the main airflow. Not at present an issue, system runs cool, and is relatively quiet, in spite of the number of intakes and the exhaust. Add to that a rather healthy radiator and four more fans mounted topside, and the passive heatsinks pretty much disappear, regardless of how uncluttered the interior is. And to my line of thinking, this would seem to indicate a possible problem with cooling down the road on a board level.

Best option here, being logical, would be to simply upgrade to a more capable motherboard, and in light of the additional shortcomings for my purposes, will probably be the avenue pursued.

The system hasn't had any issues whatsoever since making the manual adjustments. I've not really pushed it to extremes, but have used it for what I normally do with no problems, so I'm pretty well satisfied, and have more options should they be required.

[Tradesman]

Sounds like you've got it under control and have a plan, Good going! Keep in touch with what you do, C ya!