fx-8120 memory controller limitation

[Jawbone]

Hey there. New to the GSKILL Forums but not new to forums in general, so please refrain from the "try searching, noob" comments. Trust me, I have. If you want to link me to a specific forum thread pertaining to my problem, then great.

Buying the Asus Crosshair V Formula board, and an AMD FX-8120 cpu. My problem is with what RAM to acquire. Right out of the starting block I wanted to buy the GSKILL Ripjaws X series 16gb (4x4) 2100 but after some research, found that Asus will not support this memory set with 4 dimms for the two channels. --Is this correct information?

Also, noticed that the clock frequency limit supported by the FX-8120 was 1866mhz, but then seeing plenty of people having issues with running this setup stable, and reverting back to 1600.

So my bottom-line question. Is running this setup possible with 2100mhz OC'd memory, and if not, is 1866mhz, or do I need to go down to 1600? Basically, I want to buy the fatest STABLE memory set for my system, but I also want 16 total GB. (Unless someone can explain why a faster 8gb would be more beneficial than slower 16gb)

Thank you very much, for all your help!

A bit of background, I'm very comfortable with "tweaking" and poking around the BIOS. If I get specific instructions, I have no problem setting voltage and timing. I just want to make sure I'm not going to BSOD every few hours.

-J

[GSKILL TECH]

haha we're not that mean here, we're grown ups. :P

DDR3-2133 is difficult for AMD CPU. Also, it depends on your overclocking capabilities, so if you have no experience, it can be frustrating and more difficult.

Just get it, we're here to help anyway, we're not going to ignore you.

Worst case scenario you operate them at lower timings, so either way you get what you pay.

Thank you
GSKILL TECH

[Jawbone]

Ok, good to know I've been apart of some pretty nasty forums before.

That's a good point though, I guess I could just get the higher frequency and run it lower if I'm unable to run it at the posted speed.

Is it actually possible? I mean, have you heard stories of people actually making that high of frequency work even though both AMD and Asus say no?

[Jawbone]

specifically I was looking at the F3-17000CL11Q-16GBXL model RAM. http://www.newegg.com/Product/Produc...82E16820231473

Think that would be ok for my system? Of course, like you said, I could just run it at lower speeds and timing. but is it overall compatible?

[Tradesman]

I've seen and read that the 8120 will only support 1 DIMM per channel at 1866 and above or 2 total, which would seem to keep in line with AMDs past, it's happened with their CPUs at 1066, 1333, 1600 and appears now with 1866, the entry CPUs that can run those speeds have been restricted to 1 stick per channel, and even then were often very difficult if the sticks were 4GB, If going 16GB, think I'd suggest 1866 at the high end and sort of plan to run them at 1600, which may take some tweaking

[Jawbone]

Ok, so that confirms my suspicions on that. I was pretty sure only 1 dimm per channel, which is rather depressing. Haha.

Now I'm debating between the 1600 and 1866. Only because it's about double the price, and if I'm going to be running them at 1600 anyway, I might as well save the money. I guess. Then again, if I ever decide to change out my CPU providing AMD makes one that can handle more, then I will have faster ram for the future. Blah.

Either way, thank you for your help, all of ya

[Tradesman]

Another thing you can look at is to compare sets vs price, i.e. 1866 sticks at CL9, roughly equate to 1600 sticks at CL8, which are only a few dollars different (and in some cases the 1866 are less than 1600 CL8), plus if you go 1866 you can still run them at 1600 CL8 (roughly the same performance) or sometimes even CL7/1600 which can be better performance than native 1866/CL9

[Tradesman]

Dangskill, moved your post to it's own entitled New-Dangskill

[Gunite]

I have my F3-17000CL11Q-16GBXL running very stable at DDR3-1866 CL 8 10 9 27 2T @ 1.55v with all four sticks in on a ASRock 970 Extreme4 mobo with an FX 8120. Haven't had any luck as of yet getting them to run at the stated speed of DDR3-2133 though even with only 2 sticks in. I'm not thoroughly trained in the OCing ways so you may have better luck then I. Depending on your bios I would imagine 1866 is obtainable though. I had to update my ASRock bios to achieve the 1866 speeds though and I am supposedly able to get all the way up to 2400 but to honest I'm not seeing it even after reading about OCing for weeks on end now Good luck.

The one thing I seem to notice though in the reviews on Newegg is that all the ones that have achieved DDR3-2133 seem to have a FX 8150

[Tradesman]

And generally with only 2 sticks, have seen odds and ends over the weekend of folks saying they cantacted AMD , especially on the 8120 and are being told 1 stick per channel at 1866, pushing beyond that is OCing and not covered by warranty....sort of sounds like large amounts of DRAM and high frew is causing problems, sent them a work ticket today to try and get confirmation in writing