Is this RAM causing freezing/lockups?

[livingegg]

CPU: Intel Core i5-760 2.8GHz
Mobo: GIGABYTE GA-P55A-UD3
Mem: G.SKILL Ripjaws Series 4GB (2 x 2GB)
GPU: GIGABYTE GV-N460OC-1GI GeForce GTX 460 1GB
PSU: SeaSonic 850W ATX12

OS: Windows 7 64-bit

I am experiencing transient freezing and lock-ups on my new machine (homebuilt). The timing of the issues seem to be random - it could happen several times in a day and then not happen once for 2 days only to happen again. I have had freezes at various points of the boot process, including post (right before ram was posted), as well as during the windows loading process, while windows is running, and even in safe mode. The only place I've never had it freeze is in the bios itself.

Investigation up to this point has lead me to believe this is due to either defective ram, defective mobo, or incorrect ram settings in the bios. I want to continue to narrow things down here and need some help understanding the ram configuration in the bios.

Here is the advertised timings and voltage for the ram: 9-9-9-24-2N / 1.5V
Also, the advertised speed is: DDR3 1600 (PC3 12800)

Now in my bios settings, after load optimized defaults, the timings and voltage match perfectly. However the frequency is set to 1333 instead of 1600. Should this be a problem?

I did some subsequent research and found that the ga-p55a-ud3 when used with an i5 will not support 1600 without overclocking. So I tried enabling XMP, which boosted my ram speed to 1600, and for a while this actually seemed to fix the problems. However, this also overclocked my CPU and I don't want to do that - so I disabled XMP and I'm starting to see transient lockups again.

My understanding was that the ram should be able to scale back to 1333 without issue - so my findings here seem strange. How is it possible that enabling XMP could have fixed the issue? According to the bios xmp didnt actually change the timings - it changed the bclk from 133 to 160. When setting the ram back to 1333 do I maybe need to change something with the timings/voltage as well? Or should having them set to their advertised settings always ensure stability, regardless of the frequency?

I have tried to run the newest version of memtest86 and it always reboots about 5 seconds into the testing. The multicore processor version freezes. I did get an older version to work, and scanned the ram several times, it passed with no errors.

Thanks for the help,

-g

[livingegg]

CPUID Screenshots

I took some screenshots from CPU-Z both with and without XMP. I want to be able to run this RAM without XMP, but having XMP enabled seems to eliminate the freezing.

CPU with XMP Disabled:


CPU with XMP Enabled:


Memory with XMP Disabled:


Memory with XMP Enabled:

[GSKILL TECH]

OK... let me explain what's going on.. (everything is normal, and seems to be working fine)

"Load Optimized Default" simply puts everything to AUTO. On AUTO, the system is only capable of DDR3-1333 CL9 MAX. That is the highest it can detect on it's own. Anything above, an XMP (Extreme Memory Profile) must be used, or manual settings. So what happened is when you enabled XMP, the system automatically set the memory for you. The BIOS is written/tested specifically with G.Skill memory, so it already knows the CPU must be slightly adjusted. You said the XMP overclocks the memory, but you are wrong, it's the opposite. As you can see if your picture, the XMP set CPU to 2.8, which is it's rated frequency. XMP disabled, it is running Turbo mode, which is why CPU frequency becomes 3.3GHz.

So XMP is exactly what you want. If you want to overclock back to 3.3GHz, then you will simply need to raise CPU Ratio. Otherwise, just enable XMP and everything will be set to what it should be.

Thank you
GSKILL TECH

[livingegg]

Thank you for the reply.

The XMP jacked up the voltage/heat on my CPU but slowed down the speed (as you said it disabled turbo), so running XMP I had to install an aftermarket heatsink just to keep the CPU cool. That doesn't seem right to me - I'd rather keep turbo enabled, keep the voltage/heat down, and just run the ram at 1333. Is there a [stable] way to run this ram at 1333 or do I need to buy a different ram chip for my mobo? (btw my mobo is a gigabyte p55a-ud3, not asus!)

Thanks,

-g

[GSKILL TECH]

CPU temps go up because more load is placed on the memory controller, which is embedded in the CPU. The added heat is perfectly fine. Of course compared to DDR3-1333, it will seem HOT, but it is not. As long as temps are below 80 degrees under load, the system is fine.

If you want to keep Turbo enabled, instead of overclocking the CPU, then simply use DDR3-1333 8-8-8-24 timings.

Thank you
GSKILL TECH