3333 Corsair Memory Unstable on Asus R5E10

Hi. I'm wondering if anyone can help me with some ideas. I bought a 4-module 64G Corsair Vengeance LPX memory kit, CMK64GX4M4B3333C16R. It should be listed in my system specs. New build over a Rampage V Edition 10 MoBo.

 

This first part here is an aside for those who are reading, but the manufacturing QC was garbage. On one of the chips the heat spreader was separated and wouldn't close the two sides down, because the chip itself was offset (lengthwise) in the heat spreader casing. Not surprisingly on first boot it wouldn't seat correctly nor be recognized. After trying several times it finally did and "appears" to be working ok. I still may send it back because now I'm suspicious of it.

 

The question here is I cannot OC this memory over 3000 MHz. At the listed 3333, in the BIOS screens it keeps locking up randomly after 2 minutes, 3 minutes, 5 minutes, whatever time it feels like it.

 

I reset the memory to target speed at 3000, rebooted into BIOS, and it has stayed on for hours with no issues. At the moment that's all I know. I am not an extreme tweaker, so I might just leave it there and be happy. However, if anyone has any ideas that can help me get out of these chips all I paid for, I'd be glad to hear some suggestions. Voltages or other settings that may work for me to get to 3333 MHz on this MoBo, which should be able to handle it.

 

My rig is listed in my system specs, and after monitoring I know there are no temperature issues, everything appears normal. Any ideas anyone? Or also, please tell me what information you need from me in order for you to suggest a response. By the way, I did read the sticky thread at the top here, so I know it might never work right, lol.

When you tried 3333, was that with XMP enabled? What Q-Code did the board show on lock up?

 

XMP tends to be hit and miss on some boards. There are some other variables affected when you toggle XMP and the System Agent voltage tends to be gratuitous, if I am being kind. The Asus X99 boards seem to do better when you get the primary 4 timings to your XMP values, then let the board select the secondary and tertiary values by leaving them on auto. Set DRAM voltage manually to 1.35 for both banks back on the Extreme Tweaker column.

 

If you can't get 3333, my suggestion would be to try 3200 instead of 3000. The natural strap for 3000 is 125 and that triggers some other changes besides slightly harder math, most notably the disabling of adaptive voltage. You can run 3200MHz on the 100 strap and that is friendlier in most ways. I haven't spend much time trying 3333 as that was a difficult jump from 3200 for the HW-E set. BW-E is much better with this and larger capacities, but 4x16 is still a heavy batch of memory to run that high. If stability is paramount, 3200 might be a safer option all the way around. Try the 16-18-18-36 primaries first at 3200 and if successful, that can likely be tightened to 15-17-17-35. System Agent voltage is a little trickier since the base value is unique to each CPU. Try a +0.15-0.20v offset to start, but this often requires tinkering, up or down.

Hi C-A, thanks for your response. Ironically, I was so distracted with trying to get it working again that I forgot to look at the Q code when it hung up during the memory speed tests. However, I had noticed several different codes during the trials of getting everything recognized, 6d and 6f showed up several times but I'm not sure what was showing when the 3333 started hanging it up. I could go back and try it again to see, but I'm sorry at the moment I can't say positively....

 

XMP: Yes I did enable it. The memory speed was not recognized as 3333 MHz until I enabled XMP, I think prior to that it was 2100. I spent several boots trying to get the one chip to seat so I might've missed something in the interum. I did then enable XMP and immediately got many more speed options in the dropdown. I noticed that I could set the speed higher in BIOS prior to enabling XMP but 3333 was not one of the options until I enabled XMP.

 

DRAM voltage was hovering right around 1.35V for the banks of memory so I didn't see it necessary to change that. Should I force it directly to 1.35? It did look good after just sitting and observing where it was (but at idle). I was afraid to boost it since I read over 1.5V and it gets dangerous. But they are almost right on 1.35 on AUTO at idle.

 

Timings on the chips looked correct per the stamped numbers on the box/chips. Should I change those? I read through your last paragraph below and will try the 3200 settings you suggested. I don't understand what makes all the math click better, but I don't disbelieve you are correct so I will try that. I agree I have more memory than needed but just trying to edge it out for the heck of it. If 3200 is stable I can live with that. ;):

 

I must say, I did change some things but I was quite impressed with the MoBo and BIOS after going through all the screens, and am quite happy with the way it coordinated with all my components and their settings.

That's OK, don't worry about the Q-codes. They are not all that helpful, but occasionally it will indicate you are chasing the wrong problem. Definitely don't go back and re-create one.

 

When you enable "XMP tuning" at the top of Extreme Tweaker column (advanced BIOS) things get a touch complicated. It will automatically change some values. You can go back and override many of those with your own settings, but some items will allow you to change them, then use the XMP values anyway. Definite learning curve there. The rest of the time, just set that option at the top to manual and you will have a free hand.

 

I am not sure why 3333 did not appear in DRAM frequency drop down list. What's there is up to the BIOS programmers, but that is a common speed and I have some stranger ones than that on my 2nd gen X99. 3200 will certainly be there. Perhaps I misunderstood. If XMP was still enabled, no other frequencies may appear.

 

The "harder math" remark was mostly in jest. The strap will be change the effective Base Clock (BCLK) from the standard 100 to 125. This affects both CPU and Memory multipliers. So to make 4.0 GHz CPU frequency, you need a 32 multiplier (x 125 = 4000) instead of a 40 (x100 = 4000). Asus had previously removed the forced strap change to 125 when at 3000, but they made a lot of negative changes in the last BIOS or two and I don't know if that is still true. At any rate, the real reason to use the 100 BCLK is to keep adaptive voltage functioning and to minimize jitter if you have a lot of PCI-E devices. Also, if the strap is changing as you change memory speeds, you may notice your multiplier values reset. This can be maddening until you know why.

 

Leave the the DRAM voltage at 1.35v. The XMP will keep it there. When setting manual timings, you must go down and set it yourself. If you leave it on auto, the BIOS will overcompensate. A manual 1.35 for AB and CD is fine. My preference would be to tweak other values before adding anything to DRAM voltage. If you are right on the edge, a tiny .02-.03 bump might be in order, but that is the last step. System Agent voltage (SA or VCCSA) is just below the CPU voltage farther down the Extreme Tweaker column. It will have an offset box and I would try the +0.15-0.20 suggested. The default value at 3200 may be more than 0.30v -- which is near the upper limit.

 

I am sure the primary XMP values are being correctly put down off the modules. The stability issues tend to revolve around the secondary and tertiary timings much further down. You will not find those on the box and if needed, you must use some type of software to read them. They don't always show in the BIOS either when XMP is enabled. The reason to let the board assign these values is XMP is just a universal preset. Those Corsair modules are tweaked with the hopes of working with the greatest number of boards and CPUs. The Asus table written into the BIOS will have been designed for your board and your CPU family. Asus' primary concern is getting the system to boot and the auto timings are likely just a little bit softer compared to the XMP values. We do want the PC to boot and tweaking tertiary values to recover <1% read/write/copy speed is for people with a lot of patience and a lot of extra time.

Great detailed response, many thanks. ;): I am at work away from the machine so when I get back to a chance to browse I will check all those settings. The frequency wasn't OC'd at 4 GHz, if I remember correctly (not at the machine now) it was capped at 3.75. Not sure what multiplier got me there but that's what I remember. Intel says it should go to 4.0 so maybe I need to change something there.

 

Also I'll take your advice: Q is happy, so I won't test him.

No, the 4.0 was just an example of what can happen when overclocking memory and the CPU at the same time. Your default cap on 6950X is 3.50. With the new turbo mode, a single core can reach 4.0. I am not sure how Asus handles that. The "Multi-core enhancement" usually takes all cores up to the normal boost cap of 3.5, then you may get some single peaks between 3.5 and 4.0. When you change straps, it will always default back to those values, just with a different multiplier for 100 (30) and 125 (24) for the base frequency.

I haven't had a chance to mess with this yet. Got a lot going on ATM, but I will come back to this and report when I can get to it, hopefully next week. Just wanted to report that after hours of use this system is very stable at the 3000 MHz automatic XMP settings. CA thanks for all your input here. ;):