Originally Posted by fommof
Originally Posted by shad0wfax
RAM timings aren't necessary to adjust, if you're using XMP DIMMs, as they'll read the information right off of the SPD and should be timed perfectly. The only reason to set them manually would be if you have RAM that isn't setting itself properly by SPD, such as with a DIMM that is not on the "qualified hardware list" for the motherboard and BIOS version that you have, or if you're overclocking your RAM.
Again, call me crazy but i don't trust any of the important settings to be on Auto. I even "harcode" PLL, VCCIO, VCCSA etc because i simply don't trust any of the Auto settings. I would if Asus explained how exactly these Auto settings work (what's the value per freq and so on).
RAM timings are set by the SPD and based on JEDEC standards. In other words, all of the timings are stored in a tiny file on your memory modules themselves. If you change DIMMs the memory timings will automatically change when you go through the POST process to the SPD values.
This has nothing to do with Asus, Gigabyte, MSI, ASRock, evga, or any of the other motherboard manufacturers.
The only time that the motherboards come into play is when you have a motherboard that's only rated to handle say, 1333, 1600 and 1866 DIMMs and you put in some 2133s. The SPD on the 2133 tries to put timings (and frequencies) to the board that the board can't set, so the board will under-clock the DIMM (such as forcing a 2133 down to 1866 in XMP mode) and then subsequently tighten the timings (such as bumping them "up" from CL9 to CL8). These values are set during the POST and become fixed, and are not dynamically adjustable like some other "Auto" settings on motherboards are. (In other words, they won't shift around during operation like an automatic core voltage would.)
I did manually set my PLL, VCCIO, etc.
As a matter of fact, I think that it's high-time I posted an updated BIOS profile.
To illustrate my point, here is are two pictures of the SPD information:
SPD 2 Image (Click to show)
SPD 4 Image (Click to show)
As you can see, in the left column is the standard JEDEC information, that is standard to all PC12800 DDR SDRAM. The column to the right contains the SPD Extension, which in this case, is Intel's XMP. The XMP settings feature tighter timings on the tCL, tRCD, tRP, tRAS, tRC, tCWL and Command Rate. Interestingly, the tFAW and tRFC are looser timings.
The XMP profile, set by the manufacturer of the DIMM (G.Skill, in my case) uses additional bits available in the SPD, to offer a faster alternative to JEDEC in the form of an extension. These values are all in the DIMM itself, and the BIOS simply reads them and stores them when you set things to "Auto" mode.
And here are the results when you allow the Asus BIOS to use automatic settings for the DIMMs. Notice that there is no reason for me to touch any of the timings or settings here unless I choose to overclock my RAM.
Automated DRAM Timings 1 (Click to show)
Automated DRAM Timings 2 (Click to show)
The pictures below correspond to the remainder of my pertinent BIOS settings, reflecting my change to using a slight negative offset (-0.030) and a turbo boost voltage of 0.124 V. Note that as my LLC is set to Medium (25%), my turbo boost voltage is considerably higher than it would be were I using LLC of High (75%) or Ultra High (100%). I see no reason to use higher values of LLC, although I may experiment with it with a reduced turbo voltage setting while retaining the negative offset or possibly increasing the negative offset.
As it stands right now, I am at 1.336 to 1.344 Vcore (1.340 V average) at 100% load and the maximum voltage recorded during a transient is 1.352 V, a 0.008V overshoot. I tried disabling LLC, but I had significantly higher overshoots when maintaining a high enough voltage to retain stability in a 100% load Vdroop condition. Some amount of LLC appeared to be necessary for me, but I have a more efficient OC with medium LLC (at 4.7 GHz) than I did when I tried the High LLC at the same clock speeds. I've been as high as 4.9 GHz stable in this manner, with only Medium LLC.
Ai Tweaker 1 (Click to show)
Ai Tweaker 2 (Click to show)
However, as you will note in the BIOS picture below, I do manually set many of the voltages, such as DRAM, VCCSA, VCCIO, PLL, and PCH.
Ai Tweaker 3 (Click to show)
CPU Power Management (Click to show)
CPU Configuration (Click to show)
Edited by shad0wfax - 2/13/12 at 4:19am