Need help with a BIOS setting on new Sandy Bridge build

Intel Extreme Memory profiles (XMP) technology provides a robust, profile-based overclocking solution for novice and experienced overclockers. Easily overclock your platform by selecting the predefined profile in the BIOS, or manually adjust frequency and timings to extract maximum performance from your system.

Some mobos detect the XMP performance feature and offer that to u to enable it. That is all.

U can leave it be. It can only help. Don't worry about that.

Yes, Prime 95 will test it for u Sueisfine ^^^, run that : )

Thanks a lot to both for your answers!

I did look in the manual but there's absolutely no mention of it  

I also use CPU-Z and HWMonitor like you mentioned. According to CPU-Z, the CPU is indeed idling at 1.6ghz. I didn't check it shifting up to higher speed but am gonna check that once I get home.

I apologize for the noob questions but I just wanted to make sure that by answering "yes" on that "enhance CPU performance" pop-up I was not doing anything that might decrease the life span of my CPU or something :S

I also did about 1 hour of gaming using a game which has some particularly CPU-heavy areas in it (i.e. RIFT @capital cities) while monitoring temps with HWMonitor. The max temp for the cores after that session was 46º. Since I read TJmax for i5 2500k is 98º I suppose those are fine, right?  

Thanks a bunch again for your time and suggestions!

No, you are fine as long as your temps (cores) are below 80 C (using stock HSF). max is approx 95C, but the CPU has built in protection.

I never recommend using the Stock HSF. The Hyper 212 is the most recommended for stock and upto a mild OC (ie 4.2->4.6 GHz).

Yeah, I forgot to mention I'm not using the stock HSF, I'm using a Zalman CNPS 9500AT that I already had on my previous socket 775 build (only had to buy the new bracket for the socket 1155).

Thanks again!

I'm using the Zlaman 9500 LED on my old E6400 (Oed to 3.2), the 9700 LED on my I5-750 (OCed to 3.2) and the 9900Max on my I5-2500K (very mild OC to 4.2/4.6)

Ok, last night I re-checked CPU-Z and it indeed ramped-up from 1.6mhz (16x) to 3.7mhz (37x) when the system started processing something (I had some windows updates to install so I noticed it speeding up during that installation).

A couple things that caught my eye though:

1) I noticed CPU-Z was showing the base clock as "100.29" and sometimes as "100.3". Since I haven't touched absolutely anything cpu related in the bios and everything is at it's defaults/auto (and indeed the bios shows the base clock as a solid "100mhz"), is this normal ?

2) After checking CPU-Z, I fired up HWMonitor and gamed for a couple of hours. I kept checking HWMonitor and the temperatures seemed normal once again (highest core temp was 44º) but I noticed that the CPU voltage showed a minimum of 0.9 (idle voltage I suppose) and the max went through several values like 1.21, 1.27 and 1.3 (highest it showed). Since I read that stock voltage for the i5 2500k is around 1.2, I got a bit worried by it showing that 1.3 :S I'll remind you that everything in the bios is at defaults/auto.


Other than that, I checked in the bios and it seems that enabling the XMP profile and answering "yes" on the "enhance CPU performance" pop-up that I mentioned in my first post haven't changed anything clock or voltage related (everything seems to be at stock values: in the cpu page it still shows 33x mult and 100mhz bclck and in the memory page it still shows 1.5v dram voltage and 1.05v qpi/vtt voltage). So it seems the pop-up "yes" option is indeed safe  

On Bus Freq - That's normal, You are looking at ONLY a 0.3 % deviation.
Normally up to about 102 / 103 is no Problem, in fact some up this to 103 to try to OC a Non-K cpu (Not recommended).

On Voltage - Don't sweat, max based on Intel spec is 1.5. Max recommended for 24/7 OC is around 1.35-1.40. For 24/7 I'd prefer a max of 1.30->1.35. You are only hitting 1.30 for short duration.

Ok, great then   I only asked to make sure since I am getting those values completely at stock and without touching bios defaults.

You've been a great help, thanks very much again for taking the time to shed some light on this matter!

Best answer selected by Sueisfine.

This topic has been closed by Nikorr