Ram OC Help

[Sycobob]

I've done a bunch of searching and been unable to find a fix for this. I seem to have a bit of a unique situation. I'm trying to overclock my ram (F3-16000CL6D-4GBPIS) to the specified speed and timings. (MSI 890FXA-GD70 v1.9 BIOS with an AMD Phenom II x4 970. I know the ram I bought isn't made for this setup, but I didn't do enough research when I bought it. I'm kicking myself now). I'm new to overclocking, but I've been fiddling for the last few days and read everything I can find, so I have a good idea about all the options and the process in general.

Anyway, on to the problem: as soon as I overclock past 1656 MHz my computer stops detecting all 4 GB of ram. Instead it only detects 2 GB. This is confirmed in Windows (7 64-bit) as well. The stranger part is that my BIOS still shows the SPD information from both DIMMs and CPU-Z sees both as well.

And the details:

FSB: 250 MHz
CPU: 3.5 GHz (stock speed)
CPU-NB Freq: 2500 MHz
HTT: 2000 MHz (stock speed)
FSB/DRAM Ratio: 1:3.33 (same happens 1:4 once I cross 1656 MHz)
DRAM Voltage: 1.651 V (suggested voltage)
Timings: Auto (which ends up at 9-9-9-24-1T)
Dual Channel mode, Unganged
C1E, Cool 'n' Quiet, and Spread Spectrum all disabled
All other voltages are Auto

I've tried raising the CPU-NB Voltage to 1.3-1.4 V, raising the DRAM Voltage to 1.75 V. I've also tried 8-8-8-24-2T for timings. I'm not too worried about the timings yet, I just want to get closer to the rated speed with all 4 GB being used first. If I plug in each DIMM separately they work just fine.

Anyone have any idea what's causing this?

EDIT: Btw, since I have a thread open, quick OC'ing question. Everyone suggests raising the CPU-NB Voltage to increase stability when OC'ing RAM, but when I get to 1.140 V in the BIOS it turns red. Most people say to set it close to 1.3 V. The red makes me nervous, but that's the correct voltage to adjust right? I have a NB Voltage option too, and that one lets me get to ~1.4 V before turning red.

[Tradesman]

To hit 1600, take a look at the sticky:

http://www.gskill.us/forum/showthread.php?t=7688

which should get you started, on your OC question yes it will be the CPU/NB and prob a little extra to the vCore

[Sycobob]

That thread is one of the first I read. I can hit 1600, but I'm aiming for the listed 2000 MHz. As soon as I get above ~1650 MHz my computer starts seeing 2 GB instead of 4GB.

[Tradesman]

Going to need a large OC and more voltage - and then not sure if you can hit it with a 970. Gskill might have an idea or two, they should be back around Monday (PST). Sorry bout that. Maybe someone will be around tonight or Sunday that does more w/ AMD

[Sycobob]

Yea, I'm not expecting to be able to hit all the numbers exactly, but I'm hoping to get close. What really has me wondering though, is the disappearing ram a normal result of unsuccessful overclocking or is something odd going on here? Thanks for the replies btw.

[Tradesman]

Can try reseating the sticks, but at times, especially with AMD if you go to what it sees as an extreme OC, it befuddles the MC and causes a hard crash, which may or may not be enough to screw up the BIOS, reseating will normally get it back showing or could try resetting the mobo CMOS using it's jumper.

Might also want to check w/ MSI and see if they will even give you a number of what is suppose to work, if they will, I'd almost bet they will say a max of 1-2GB at 2133, maybe 2 at 2000 or even 1800
- do they even list any sticks that fast on their QVL?

[Sycobob]

I've moved and reseated the sticks a few times to narrow down causes. They are definitely seated good atm. I've also done quite a few CMOS resets while OCing. Before I realized it was only showing 2 GB past 1650 I had it up to almost 1900 MHz. Is there any chance this is being caused by a setting I missed? Something that disables stuff on the fly? Idk, I'm stabbing in the dark.

The QVL list for memory seems to be rather sparse. The highest clocked ram they show is 1600 for which they list 3 combinations of 2x2 GB dimms.

I noticed I can bump up the CPU-NB Voltage to 1.3 V and get 1-2 more MHz out of the ram before it stops recognizing all of it.

[Onslaught2k3]

Why are you increasing the FSB anyways? All you have to do is raise the multiplier on the RAM to get the DDR3-1600 speeds you want anyways. You have the Pi series RAM, the RAM multi shouldn't be a problem for the modules. Also, try increasing the NB voltage to about 1.2V (which is very safe). Stock voltages on the NB is 0.8V. The NB itself is running a bit faster so give it a little boost. If that doesn't work, go 1.5V on the NB voltages for your MB. If that doesn't work, then I'm not quite sure what else to tell you. How's the cooling on the CPU? If you leave it at stock speeds, chances are the IMC on your CPU (you didn't specify which model yet) needs better cooling to handle DDR3-1600 speeds?? I would also recommmend a CM Hyper 212+ for half-decent air cooling on your CPU.

NOTE: I wouldn't recommend going beyond DDR3-1600 especially on a C2 revisioned chip. If you have a C3 revision chip you may be fine trying to OC to DDR3-1800. Thuban (hex-core chips) have the best IMC on AMD chips to date and many people don't have issues hitting DDR3-1866 speeds on capped overclocks for their cooling solution (water, high-end air cooling). I assume you have a quad-core chip. Instead of jumping the gun on going to DDR3-2000, tighten timings on the RAM to CL7 speeds and see if that works a bit better. Keep the modules slightly lower than spec voltage.. tell me how that goes for you.

[Tradesman]

I can't think of anything off hand, will try to check into it further, but, again, just don't think the 970 has it in it, short of taking it to a meltdown voltage/heat extreme (in effect a suicide shot) in OCing. Will check back on this later in the afternoon

[Sycobob]

I have to increase the FSB to get higher than 1600. I tried both 1:3.33 and 1:4 multiplies for the RAM to see if it was an FSB or RAM issue that was causing it not to show up. The exact same thing happens either way. I'm inclined to run the ram at 1:3.33 and leave the NB multiplier at x10 to keep the NB : DRAM ratio at 3:1 like I've read you need to with AMD CPUs. Like I said before though, I'm aiming for 1800+, not just 1600.

When you talk about increasing the NB voltages, do you mean the actual NB or the CPU-NB? I thought only the CPU-NB made a difference in stability.

I'm using an AMD Phenom II x4 970, which was in the first post. I don't know the revision though, I'll find out when I get home.

I'm using a Zalman CNPS9900Max for cooling. With the ram at 1600 MHz and the CPU at stock speed I sit a 30 C idle and 47 C under load (Prime95). The overclock to 1600 is perfectly stable, it passes both Memtest and Prime95 torture tests without errors (only gone for an hour on each at this point). It's also still perfectly stable when I pass 1650 MHz or so, I just lose half my ram when I do.

Not to beat a dead horse, but my biggest question at this point is still whether disappearing ram is a normal thing to happen with an unsuccessful overclock, or is something else going on?

[Tradesman]

CPU/NB...and no it's not normal for the DRAM to disappear, could be a glitch in the BIOS, a bad slot, bad stick, PSU, faulty CPU (MC in particular)......

[Sycobob]

I think the sticks are ok since they work individually just fine. It happens in any configuration of slots also. That leaves CPU, BIOS, and PSU. Any thoughts on how to narrow it down?

CPU-Z reports the revision as RB-C3, btw.

[Tradesman]

You may just have to wait and see what GKill says, I've already said a couple times, I don't think your CPU or any 970 can do it.

[Sycobob]

Yea, I'm prepared for that, if it ends up being the case. I'm only trying to be sure before I give up. I'm going to see about swapping stuff out and seeing if I can narrow down any particular component.

[Tradesman]

The official line on the 970 (and actually most all of their higher end CPU's is DDR3 1333 DRAM) can be found here:

http://www.amd.com/us/products/deskt...omparison.aspx