My memory is rated at 1066MHz 5-5-5-15 2.1V and has an Extreme Memory Profile (XMP). In BIOS the options are "Auto", "Profile2", and "Disabled". I'm currently overclocking the CPU but planning to keep the memory at stock values. My overclocked system passes Intel Burn Test and OCCT at 3.99GHz but keeps failing Prime95 at even 3.90GHz. So I'm wondering if it's the memory settings?

 

Q1) What exactly does "Auto" configure (I assume Profile2 is the XMP profile)?

Q2) Does the XMP profile keep the dram voltage at 2.1V?

Q3) Should I disable XMP and set all the memory values manually?

Q4) Is it better to set the dram voltage manually when overclocking the system?

 

Current memory BIOS settings are below (I set "Performance Enhance" to "Standard" when testing a higher overclock). Thanks in advance for your replies.

 

 

Q1) What exactly does "Auto" configure (I assume Profile2 is the XMP profile)?

Q2) Does the XMP profile keep the dram voltage at 2.1V?

Q3) Should I disable XMP and set all the memory values manually?

Q4) Is it better to set the dram voltage manually when overclocking the system?

 

 

Q1: Most memory kits come with 2 pre-programmed XMP profiles. Profile 1 and profile 2. Generally profile 1 is the advertised spec profile and profile 2 has lower speed but tighter timings. Some kit manufacturers make profile 2 higher speed but looser timings so it varies. Auto normally selects the default profile which is normally the advertised specs.

Q2: Part of XMP is to use manufacturer specified settings including volts. The XMP profile will automatically set the correct voltages required for stable operation at the profile settings. These settings have been validated by both the memory manu and Intel.

Q3: It is always good to keep an XMP setting since the memory was validated to run at that value. However, OC'ing can require you to modify your ram settings, speed, volts, etc. If you notice the settings you want are not the same as reported in the bios or if you need to modify the ram settings (looser timings) to keep you OC stable than do manual. I OC all our machines and never had to switch from XMP profiles but your machine and the combination of components might need some hand tweaking but generally an XMP profile should be fine.

Q4: The only time I have had to manually change the dram volts is on heavy OC's or when the XMP profile was not set right. In that case the dram was bad anyways.

 

Have you checked your with memtest to make sure the sticks are good? Normally if you can pass IBT on high or maximum your OC is fine. IBT IMO works better at stressing a CPU OC than Prime and in less time.