XMP Technology Implementation

The assembly process went on smoothly. We also revealed no problems during work in nominal mode. However, like any other mainboard, EVGA X58 SLI Classified does have certain peculiarities. The first one is connected with the implementation of XMP technology (eXtreme Memory Profile). If you want to use settings profiles recorded in the SPD of Kingston HyperX KHX14900D3T1K3/3GX DDR3 memory modules, you will need to change the “memory SPD” setting in the “Memory Feature” sub-section of the BIOS.

I was a little surprised that only the anticipated memory frequency was changing in this case and all timings (as well as all voltages in “Voltage Control” sub-section) remained set to Auto. It would be much more convenient if they changed right away. Right now, however, we can only see the actual settings the board makes only after rebooting.

After reboot we see that the board set all timings recorded in XMP absolutely correctly for the 1867MHz frequency. After rebooting we can also see the voltages set by the mainboard. The memory voltage was increased to 1.65V and the voltage of the part of the chipset North Bridge containing the memory controller integrated into the CPU – CPU VTT Voltage – was raised by 300mV (0.3V).

It is interesting to recall that Asus and Gigabyte mainboards set the memory frequency at 1800MHz if you selected the second profile. It is a non-standard setting that cannot be obtained in a common manner – by selecting an appropriate memory divider. The list of standard frequencies includes 800, 1067, 1333, 1600, 1867MHz, etc. In this case, Asus and Gigabyte mainboards perform a few pretty complicated manipulations. They raise the base frequency from 133MHz to 150MHz to obtain d1800MHz memory frequency, but at the same time lower the CPU clock multiplier to make its resulting clock speed as close to the nominal as possible despite the increased base frequency. EVGA X58 SLI Classified does it in a simpler way: if you select the second XMP profile, it sets the memory frequency at 1600MHz raising the voltage on the modules to 1.65V and setting CPU VTT Voltage 250mV higher.

Even in the nominal CPU mode “CPU VTT Voltage” on EVGA X58 SLI Classified mainboard is set relatively high and equals about 1.23V. For the sake of comparison I have to say that its default value on Gigabyte mainboards is 1.175V, and on Asus ones – 1.2V. Therefore, increasing it by additional 0.25-0.3V seems to be little too much, which we have successfully proven during our test session. 0.1-0.125V increase in the “CPU VTT Voltage” proved enough to ensure memory stability at higher frequencies. You should lower the default voltages on EVGA X58 SLI Classified mainboard not only because the system will run too hot with them increased that much. The board has one more peculiarity: under heavy load it will increase the voltages quite noticeably. However, we are going to talk about it later in this article.