Need help OCing the AMD 965 on a Crosshair III Formula

[dkhman26]

Here's my system:
Antec 900 Case
Antec TPQ 850W PSU
Asus Crosshair Formula III
AMD Phenom II X4 Deneb 3.4Ghz (965 C3)
Mushkin 996657
Sapphire Radeon HD 5870
2x WD Raptor 1x WD Velociraptor
Windows 7 x64 Professional

I bought a nice cooler that keeps my proc nice and cool, but I can't get a stable OC at 3.9Ghz.... I think I may be missing a setting that might help with my OC. I have gotten some system crashes while testing the stability at 3.9Ghz and the Windows log states that there was a "Memory hierarchy problem" I'm assuming this means something to do with the L3 or L2 cache on the proc.

Voltages are as follows:
vCore - 1.48
CPU/NB - 1.5
DRAM - 1.9
NB - 1.5
SB - 1.2
CPU VDDA - 2.9

I've got the bus speed at 270 with a 14.5 multiplier to get me 3915 mhz, but I keep getting rounding errors in Prime95 after just a few minutes. I have noticed that my vCore seems to be a bit unstable, as it rises to about 1.51 under load, but sometimes it dips back down to 1.49 or 1.48.

I also have the HT link and NB Frequency running at 2700. With my new cooler, the temps haven't gotten above ~46 C, but I haven't been able to really burn in before I start getting errors, so I don't think heat is a problem.

I've read a lot about people hitting 4.0Ghz or higher on air (and way higher on liquid cooling), as long as they can keep temps under control and I'm not seeing any temperature problems in my rig, so I'm hoping I'm missing something that someone else can point out for me so I can get this baby stable at 3.9 or 4 Ghz. If I run the "small FFTs" test in Prime95 (which doesn't test the RAM) I've been stable for 15 minutes (that's where I've stopped it to do the "blend" test). So I'm thinking there's an issue with the memory system. Hopefully someone can help me with this. The memory itself isn't really OC'd. It's supposed to run at 1600mhz, but I've downlocked it to 1440mhz and tightened the timings (which according to Mushkin it should be able to handle).


Thanks in advance for your help.

 

[dkhman26]

RAM

So I guess the problem is the memory controller on the AM3s.... This RAM does not OC well on AMD boards. I can't run it at 1440 at 6-6-6-18. I had to bump it back up to 7-7-7-20 and now I'm stable with the proc at 3987 and the RAM at 1466. When I first started OCing and testing the RAM, I couldn't get it stable past 1633 and the guy from Mushkin basically blamed the AM3 memory controller stating that he has sticks that run at 1780 on the default 7-7-7-20 timings on an Intel board and he can't get it past 1640 at those timings with the SAME physical sticks of RAM on an AMD board.

 

[QuietIce]

to OCF!


46°C at load with that vCore is pretty good! What CPU cooler and fan are you using and are you measuring core temp or CPU temp?

You should probably turn down the HT link speed. It's only rated for 2600 MHz and unless you're running CrossFire you won't see much of a performance boost above 1600-1800 MHz anyway - 2000 MHz tops.

RAM speed above 1600 MHz is a non-issue since a cpuNB of 28-3000 MHz would be needed to use anything that fast ...

 

[Marshmallow64]

Yea ram is hard to overclock for the AM3 boards =(. Make sure your temps don't go above 55 C for load.

 

[dkhman26]

RAM

So it turns out my problem was the RAM... After getting some great support from Mushkin, I was able to get my system stable at 4Ghz.

Here are my settings:
Bus - 276
Multiplier - 14.5
HT Link - 1932
NB Freq - 2760
RAM
CAS - 6
tRCD - 6
tRP - 6
tRAS - 18
tRC - 27
CR - 1t
1472mhz

Voltages:
vCore - 1.48
CPU/NB - 1.48
DRAM - 1.97
NB - 1.45

Since I was finally able to do a full burn in, I hit max temps around 54C. I'm using the ASUS utility "PC Probe" to measure the temps.

I'm using this cooler. In an Antec Nine Hundred case with ambient temps around 19 - 20C.

If anyone else is having any problems with OCing their RAM on this board, I'll let you in on the secret that the tech from Mushkin gave me that allowed me to get stable at these speeds.

On the WEI I'm getting a 7.5 on proc, 7.8 on memory and 7.8 on both graphics tests. I'm a little low on the HD test a 5.6, because I'm using an old WD Raptor HD as my OS drive. I don't have the spare money to throw away on an SSD.


My system:
Antec 900 Case
Antec TPQ 850W PSU
Asus Crosshair Formula III
AMD Phenom II X4 Deneb 3.4Ghz
Mushkin 996657
Sapphire Radeon HD 5870
2x WD Raptor 1x WD Velociraptor
Windows 7 x64 Professional

 

[dkhman26]

BIOS

I just discovered that ASUS does have a newer BIOS. I used their Windows tool to flash my BIOS and on first reboot it hung at the "DET DRAM", I hit the reset switch and this time it hung at "VGA BIOS" and I heard a really loud fan. I'm guessing it was the fan on the graphics card. I finally did a full shut down and let the system sit for about 15 seconds. When I started it back up, I was prompted by the BIOS as if OCing had failed and when I went into setup, everything was back at defaults...

Anyway, the new BIOS is supposed to make OCing a bit more stable, so maybe I can bump my bus up to 280 and get stable. For now, I'm going to watch "It Might Get Loud" and I'll worry about getting a tad higher for another time.

 

[oldbrave]

For starters I'd lower the voltage you have going to the CPU/NB, I think that 1.48v is too much and that you should be able to run the CPU/NB at 1.35 without any problems and it would help cut down on some of the heat coming from the CPU.
Also you should be able to lower the NB voltage to about 1.26v or 1.28v and that might even help stabilize your system even more.

 

[Bobnova]

cpuNB stock voltage is 1.175, AMD says that the max should be something like 1.25, 1.48 is way more then you should need to use, and way more then you should use too.

 

[dkhman26]

Voltages

Oldbrave - Thanks for the extra input. I'll test out your suggestions and see what works.


Bobnova - According to the AMD spec sheet (here) the voltages can range from .825 to 1.40, so I'm only slightly over the accepted range, and from what I know about OCing, it's all about going slightly over the accepted values to get better than stock performance.

 

[Bobnova]

That doesn't say whether it's for vcore or cpuNB volts though.

 

[dkhman26]

Gotcha Bob. I misread your post.

I tried adjusting the voltages like OldBrave suggested, but I'm no more stable than I was before. I'm not Prime95 stable, but in real world PC use, I have no problems. It's this stupid memory controller issue on the AM3s. The RAM itself can handle a far higher clock, but the memory controller can't. I guess I'll have to push the bus down a few notches to get the RAM to a clock that the memory controller can handle.

 

[QuietIce]

At some point something on any system refuses to overclock and even IF the controller could handle it the cpuNB speeds you have aren't fast enough to use the increased throughput ...

 

[dkhman26]

So do you think increasing the NB freq another notch would help make it stable?

 

[dkhman26]

So do you think increasing the NB freq another notch would help make it stable?

Well, I tried that and it made my system completely unstable. Prime95 only fails if I run the "blend" torture test so I'm guessing its the RAM or something to do with the memory sub-system. Anyone got any other ideas?
I'm pretty sure heat isn't an issue as according to PCProbe none of my components are hot and my ambient temps are low.

 

[QuietIce]

Core temp is still 50-55°C or less after 5 min of OCCT or Prime95?

Turning down the cpuNB voltage to 1.30-1.35v and/or reducing the cpuNB speed one notch doesn't help?

NB of 1.45V? Do you need that much? (stock NB is 1.1v - are you sure that's the NB?)

Have you looked at the RAM refresh rate? 105-130ns or so is usually good.


Here's some other clocking using the Crosshair III. Maybe there will be something in that thread that can help ...
http://www.overclockers.com/forums/showthread.php?t=610144&highlight=Crosshair+III