Stable only when I remove a stick of RAM

[tjc320]

My computer:

Intel i7 2600K
Gigabyte z68xp-UD4
16GB (4x4gb) Corsair VengenceLP 1600 RAM
Corsair H110 Water Cooler


I've been working the last few days on getting a stable overclock but have had a pretty difficult time reaching 4.6. My goal was 4.8 but I don't think I know enough about OCing to get there. I would be happy with 4.6.

I tried everything I could according to my ability to get 4.6 but I kept having workers drop out while running Prime95.

I found that if I removed a stick of RAM my computer would run stable without changing any other settings.

Is there a setting that I can adjust that might allow me to keep all 4 sticks of RAM in while maintaining stability?

My current settings:

CPU Ratio: 46
Vcore: 1.345
QPT/VTT: 1.100
System Agent Voltage: .965
CPU PLL : Auto (1.800)
System Memory Multiplier: 16
XMP: Disabled
Performance Enhance: Standard

Everything else is pretty much auto or default. My CPU temps max at 64 at load.

 

[||Console||]

Ring voltage maybe

 

[tjc320]

Ring voltage? Sorry, I don't know what that is.

 

[redduc900]

Bump the VTT from 1.10 to ~1.35V.

 

[Bobnova]

VCCSA is the memory controller voltage. Give it 1.05v. That'll probably do it right there.
Ring voltage is Haswell stuff.
VTT/VCCIO (same thing, different names) sometimes helps too.

 

[redduc900]

VCCSA is the system agent voltage, whereas QPI/VTT is the memory controller voltage.

 

[tjc320]

I raised the QPI/VTT to 1.35 but it game me purple text ( I assume purple text was a warning that it's a high number) so I lowered it to 1.2 and it seemed to help but after about 15 minutes of prime a worker died. I raised it to 1.25 (the highest it goes before entering the purple) and it didn't last nearly as long - only about 3 minutes.

Then I raised the System Agent to 1.05 but it didn't seem to make a difference - workers still die.

Is there a magical balance I have to find between the VTT and the VCCSA?

 

[Bobnova]

VCCSA is the system agent voltage, whereas QPI/VTT is the memory controller voltage.

QPI doesn't exist on LGA1155, that's 1366/1156.
QPI/Vtt is the Uncore voltage (everything but the core) on 1156/1366, not 1155.
It (vtt/vccio, no QPI here) is a communications voltage on 1155.

VCCSA is indeed the System Agent voltage on 1155, which includes the memory controller.

What is called what and what does what varies by platform.

 

[tjc320]

My board is 1155 but in the BIOS it says QPI/VTT. Must just be standard labeling for GIGABYTE platform.

Should I focus on finding the correct VCCSA then if it deals directly with my memory?

 

[Bobnova]

Wind it up to 1.05v and see if it fixes things.
If not give VTT 1.2v and see if that fixes things.

 

[redduc900]

Disregard the BIOS warning and bump VTT to 1.35V while leaving VCCSA on Auto.

 

[Bobnova]

http://www.techreaction.net/2011/01/04/3-step-overclocking-guide-–-sandy-bridge-v0-1beta/
http://forums.pureoverclock.com/cpu...andy-bridge-overclocking-guide-5ghz-club.html
http://www.overclockers.com/memory-overclocking-guide-ivy-bridge

Think you know more about what voltage does what than those three? Or, for that matter, Woomack alone?
Read that third one.

My personal experience with SB has been the vccsa goes further to stabilize memory / allow booting in the first place with fast memory than vccio does.
vtt/qpi doesn't even exist anymore, and is a mislabeled BIOS option. Note that Sin works for GBT, land of the mislabeled BIOS options.

 

[tjc320]

Well...I've tried quite a bit of different combinations and seem to always come up with dead workers. Here is what I've tried:

VTT: Auto
SA: Auto
---
VTT: 1.350
SA: Auto
---
VTT: 1.225
SA: 1.05
---
VTT: 1.210
SA: 1.05
---
VTT: 1.200
SA: 1.05
---
VTT: 1.200
SA: .965
---
VTT: 1.200
SA: .925
---
VTT: 1.100
SA: 1.05
---
VTT: 1.100
SA: .970
---
VTT: 1.05
SA: 1.05

 

[Bobnova]

Have you tested each stick individually?
Have you tried enabling XMP?

 

[tjc320]

I've run MemTest on each stick of RAM and it came up with zero errors.

I may have tried enabling XMP in the past but I'll try it alongside some VTT and SA changes and see what happens.

 

[tjc320]

Still no luck...Here are the test I've logged:

With XMP enabled:


CPU: 1.35
VTT: 1.2
SA: .965
---
CPU: 1.36
VTT: 1.2
SA: 1.05
*I thought this one was the trick and it ran for 14 minutes but then a worker died
---
CPU: 1.365
VTT: 1.2
SA: 1.05
*ran 5 min
---
CPU: 1.36
VTT: 1.225
SA: 1.05
*ran 1 min
---
CPU: 1.36
VTT: 1.2
SA: .965
*ran 4 min
---
CPU: 1.36
VTT: 1.2
SA: .92
*ran 9 min
---
CPU: 1.36
VTT: 1.21
SA: .92
---
CPU: 1.36
VTT: Auto
SA: Auto
---
CPU: 1.36
VTT: 1.2
SA: .965
DRAM:1.525
Load Line: 6
*>1 min
---
CPU: 1.36
VTT: 1.2
SA: .965
Load Line: 6
*Crash
---
CPU: 1.36
VTT: 1.2
SA: .965
Back to Load Line 7


None of those settings have worked. I'll keep trying different things though. The second one seemed to be the closest I could get.

 

[johan851]

It also may not be possible to stabilize it. You could try backing off memory timings or speed, since those have a relatively small effect on that platform. I ended up doing that for my 2500K. You could also only use 8GB of RAM (which is plenty for most things) or upgrading to a two stick set.