I am extremely inexperienced with overclocking and just recently built my first new build PC on my own.
- EVGA P55 SLI Mobo
- i5 750 @ 2.67 Ghz Stock/Stock
- Patriot Viper II Sector 5 1600 CAS8 2x2DIMM RAM
- GIGABYTE GTX 460 1GB GPU
- Storm Sniper Case Black Edition
- XFX 750W Black Edition
Thus far, nothing has caught fire, so... jackpot.
Now, I was looking into my RAM settings in the BIOS because I know that most RAM is downclocked by the Mobo and will not be used at its rating by default...
My RAM was set in the BIOS to ~1000 (1033?), so I immediately started looking into that (as I'd like to get the 1600 I paid for and verify it works before sending in the rebate). The BIOS would let me set the RAM to 1333, but no option for 1600. However, I could choose to load an XMP Profile which had the RAM configged to 1600- so I did that...
On next boot, it failed to post- and gave a d4 POST debug error, I cleared CMOS and manually set the RAM to 1333 and it booted just fine....
Now, I think the answer is somewhere in the CPU FSB? Is it true that most boards consider anything over 1333 to be an overclock on RAM? Will I need to increase a clock value on my CPU in order to get to a Lowest Common Denominator number that will sync with my RAM and unlock the ability to set it to 1600?
I do not dare overclock my cpu far at this time, I'll get a non-stock cooler and overclock in the next month or two, but can I get some advice as to whether the above scenario is logical for an experienced OC'er, and if you can offer any next steps/advice to either get my mobo to accept the XMP Profile, or unlock the ability to manually set to 1600? Perhaps my sticks are bad?
Best would be to leave the ram at 1333 until you get a good cooler and then you raise your Bclk to 160 and then you have your 1600 with your max memory multiplier of 10x.
If you don't want to wait, you can raise your Bclk to 160 (might have to add a little VTT and or vcore) but lower your CPU multiplier to 17-18 (2.72-2.88 Ghz). This way you get the memory running at 1600 but the CPU is still running around stock speed.
Just make sure to manually set your memory timings and voltage in the BIOS.
You memory multiplier is the speed you see it set to in the BIOS. If it's at 1333, and your BCLK (base clock) is at 133, then your memory multiplier is 10x. Try raising or lowering it, you'll see that it only goes down in fixed amounts, that's the multiplier going from 10x to 8x to 6x etc.
It works just like your CPU multiplier. 133 x 20 = 2.66, right? All of the other components on the motherboard (excluding the PCI slots) are affected by the BCLK in the same way.
Obviously, your max memory multiplier for your board is 10x. In order to get past that to get your desired RAM speed, you'll have to increase your BCLK, since you cannot increase your RAM multiplier. What you would have to do is increase your BCLK to 160, so that your 10x multiplier will go exactly to 1600, your desired speed (160 x 10 = 1600).
However, that would also affect every other component on the board, including your CPU. Now, I'm not familiar with the i5 CPUs, but I would say wait until you get a new heatsink so that you can overclock in a stable manner.
Another thing, is that you'd have to check your RAM's website or manual and find it's timings and voltage, and put those in your BIOS under "DRAM Settings" or something to that effect. The "auto" option just doesn't cut it for RAM, so you'll have to key those in manually to be safe.
Hope you can get everything to your liking. And if you don't mind, I'd like to recommend the Cooler Master Hyper 212+ as an excellent low-cost heatsink that outperforms heatsinks twice its price.