OC Memory Issues?

[oblio]

I'm confused! I've been overclocking my new I7 - 950 on an Asus Sabertooth x58 board and am quite content with being able to get 3.8 - 3.9 Ghz with air cooling after some minimal fussing. My problem seems to be with the RAM though. I've 12 GB (3 sticks of 4 gb) of DDR3 - 1333 mhz PC3-10666 (triple channel). After manually making the bios changes and rebooting my system only recognises 8 gig. If I reset the bios to defaults its back to 12 gb. Overclcok and its back to 8.

 

My settings have been typically 22 x with BCLK from 160 ish up to 177. The DRAM freq has been whatever the bios defaults to and the appropriate UCLK is selected to match. DRAM bus voltage 1.65. There is a note in the bios that says for a locked CPU 1066 Mhz must be used but the overclock generated setting is never quite 1066 mhz. I tried 22 x 177 and got 1065 mhz as the first option so I used that and the system recogonised 12 gb but then failed on Prime 95.

 

I dont understand the timing settings so could that be an issue (read about that somewhere). Any ideas why 8 gb instead of 12 showing up and how to fix it would be appreciated. Perhaps my basic question is can I even overclock the ram I have or do I need to get something faster like PC 12800 or 16000.

Edited December 10, 2010 by oblio

[El_Capitan]

Are you sure they're all in the correct slots? Where are you looking at to see it being 8GB? Are you using CPU-Z or are you looking at the Task Manager?

[sack_patrol]

Yea, I'd like to know what you're using to check the ram. Normally CPUZ is the best program to use. It never lies.

 

Other than that, I don't know what the issue might be, but what I CAN suggest is that you don't leave values in your BIOS on Auto. Try to find out all the values of all the options or as many as possible and set the manually. That way you'll be sure that whatever you've set is that and nothing else. It probably has nothing to do with your issue, but do it. It can only help.

[mattyamdfanboi]

first off.. who cares about cpuz.. lets start with basics first.. POST

 

when you post, does it see 8gb or 12gb?? are u talking about that??

 

when u boot it says uve got 8gb when its oc'd and if u dont oc POST says uve got 12gb??

 

thats extremely odd..

Edited December 10, 2010 by mattyamdfanboi

[oblio]

Yes the Ram is in the right slots and has all been tested to ensure its working properly. I thought maybe I had a bad stick but all three test out fine if I simply install 2 sticks at a time under my OC conditions.

 

If I boot using the BIOS defaults its posts 12GB, CPU-Z says 12 GB in the correct slots and my Win 7 system properties say 12 GB. Then if I change settings in the BIOS to OC (example 22 x 173, 1.65 dram bus voltage, 1.275 CPU voltage, dram frequency 1387, uclk freq 2774 plus some other setting changes), then it posts 8 gb, Win 7 says 8 gb and CPU-Z says 8 gb but only shows two sticks installed in the A2 and A6 slot, ignoring the A4 slot. The exception is when I set it up to OC at 22 x 177 (about 3.9 up from 3.06) which gave me a dram frequency choice of 1065 Mhz. This posted 12 gb and confirmed by Win7 and CPU-Z but then it was unstable after an hour of Prime95.

 

As mentioned in my first post I read somewhere that there can be timing issues with locked CPU's like the I7-950 on an X58 board where it won't communicate properly across the RAM due to variable speed issues. Because I'm using PC3- 10666 on an X58, is the issue simply it won;t overclock without these other issues because I'm pushing this "slow" RAM too far up from 1333? Or do I have to change the memory settings somehow (I think its 8-8-8-20 right now if that makes sense)? In other OC posts for an I7-950 most people have faster RAM than what I have and have no issues.

 

I'm ok with the OC settings in general, don't understand what I'm doing but can play enough to make it work by seeing cause and effect. My CPU temps are 80c or lower. I haven't seen many posts on the RAM side though as its not appearing to be an issue for most so I'm lost as to what to do. I can pop for the faster 12800 or 16000 RAM assuming that will work (?) but can what I have be made to work?

 

Thanks

[oblio]

Fussed around a bit more and found out that my BIOS was defaulting my RAM to 8-8-8-20 under default conditions and 8-9-9-24 under overclock conditions when the RAM itself is labelled 9-9-9-24 (maybe I should have seen this before). Made the manual change in the BIOS for the CL and then it started seeing 12 gb under all overclock conditions so all is now well. After making the change then saw a note in the ASUS MB guide saying may have to manually change memory timing settings under overclock conditions because the system may not do it properly, maybe I should have read and understood this before.

 

Did find out though that I can't push my PC 10666 RAM too much before it craps out, can only go to about 1387 mhz (up from 1333) even with 1.65 voltage...after that it goes unstable.