Complete BIOS Tuning Guide - "Over Voltage"

Over Voltage

CPU Voltage - [Auto, 1.10000 ~ 2.40000 in 0.00625 steps] This setting controls the processor supply voltage by manually adjusting the target CPU VID.

Our measurements have shown the ASUS Striker II Extreme to have a nominal load line impedance (RLL) of approximately 0.80mΩ meaning that for each ampere (A) drawn by the processor the regulated supply voltage will droop 0.8mV. Given this, a 45nm quad-core QX9650 CPU with a full-load power consumption of 80W should draw about 65A, resulting in a total drop of around 0.05V from idle to full-load.

Loadline Calibration - [Enabled, Disabled] Setting Enabled will effectively remove any negative feedback in the CPU supply voltage regulation circuit. This means that there will be little to no difference between the CPU supply voltage at idle and full-load. This does not mean however that there will be no offset seen between the idle voltage and the CPU Voltage VID as selected in BIOS. Disabled follows the Intel specification and allows the CPU supply voltage to droop under load as properly designed. We recommend you leave this Disabled and increase CPU Voltage as needed to satisfy the minimum operating voltage needed under load.

CPU PLL Voltage - [Auto, 1.50 ~ 3.00 in 0.02 steps] Selecting a higher PLL (phase lock-loop) voltage may help the installed CPU clock higher or may assist with maintaining stability when operating at higher FSB speeds. Most users will find they do not need to set this to anything above 1.50. Exercise caution when experimenting with higher values as there have been reported cases of CPUs losing cores after being subjected to voltages in excess of about 2.00V.

CPU VTT Voltage - [Auto, 1.20 ~ 2.46 in 0.02 steps] VTT is the termination voltage for data lines used to interface the MCH with the CPU die(s) via the Front Side Bus. Higher values can provide additional FSB overclocking margin, especially with 45nm dual-core processors and quad-cores CPUs in general. We have never found any additional gains to be had above 1.36 when using air- or water-cooling. Setting Auto should default to 1.10V for 45nm CPUs and 1.20V for 65nm CPUs. Knowing this, there appears to be a dead band between 1.10V and 1.20V where intermediate values cannot be selected - we are working with ASUS engineering to get this corrected.

Memory Voltage - [Auto, 1.50 ~ 3.10 in 0.02 steps] DDR3 memory is rated for standard operation at just 1.5V with most performance memory kits specifying the use of voltages between 1.75V and 1.95V inclusive. Increasing the memory voltage will have a direct impact on the ability to run the installed memory at higher frequencies, with tighter timings, or both. This voltage will droop slightly under load, so consider this when selecting the appropriate value. Our recommendation is never to exceed the manufacturer's maximum warranted voltage. With that said, values in excess of about 2.30V with DDR3 are a death sentence.

NB Core Voltage - [Auto, 1.30 ~ 2.20 in 0.02 steps] This is the main power supply voltage for the 790i SPP. Any of the following adjustments may require an increase in this voltage: higher memory operating frequency, tighter memory timings, enabling P1 and/or P2, the use of additional memory modules (including higher-density modules), and increases in PCIe Slot 1/Slot 2 base link speeds. We were able to reach DDR3-2000 speeds (500FSB) using 4x2GB of OCZ DDR3 with only 1.52. This is near full load for this chipset, suggesting that higher voltages will only lead to additional heating and eventual instabilities.

SB Core Voltage - [Auto, 1.50 ~ 1.85 in 0.05 steps] This is the main power supply voltage for the 570 MCP. Leave this voltage set to 1.50 unless you increase PCIE Bus, Slot 3, MHz, LDT Frequency, and/or SPP<->MCP Ref Clock, MHz and find instabilities due to the change(s).

Complete BIOS Tuning Guide - "Memory Timing Setting" Complete BIOS Tuning Guide - "Over Voltage" (Cont'd)


View All Comments

  • Rodriguez - Friday, June 20, 2008 - link

    Can anyone here indicate how to reach FSB 500 (2000) with Striker II Extreme & QX9770 C1, most I can get is 1900FSB.

    I've seen Kris reach this speed in this article & was eager to get to this speed as soon as I received my new CPU, but it has been more difficult than I thought, I was sure that if with my previous Q6600 G0 y could easily get 1900/1950FSB, now with QX9770 would be peanuts. The main reason I bought this CPU was to run 2000FSB linked & synced with Ballistix 2000 SLI.

    Please give all detailed BIOS setup options for this CPU if possible

    Nobody in Asus forum using this setup has been able to reach 2000FSB, but I have seen a few reviews (like Anandtech's) & posts showing it's possible

    By the way, memory has been tested unlinked at 2000Mhz 9-8-8-24, 1.9v P1/P2 Enabled & works great


    QX9770 rev. C1 3.2Ghz (watercooled)
    Asus Striker II Extreme BIOS 801, ver 1.02G (watercooled)
    PC Power & Cooling Turbo Cool 1200W
    4 x 1GB Crucial Ballistix PC16000 SLI EPP2 , 2000Mhz 1800 8-7-7-24- 1T - 1.9v
    SLI Leadtek PX8800 Ultra Leviathan (factory watercooled)
    SLI Leadtek PX8800 Ultra
    Asus Physx card (removed)
    Dlink DWA556 PCIx Xtreme N Wireless card
    2x WD Raptor 150GB Raid 0 300GB
    1x Seagate 400GB Sata
    X-Fi Platinum Fatal1ty Champion
    24' Benq FP241VW Gamer
    Innovatek XXD Rev 2 + G-Flow water cooling
    CoolerMaster Cosmos 1000 case
    Saitek X52 Flight system
    TrackIR 4 + Trackclip Pro
    Windows Vista Home Premium 32bit
  • parkerdw - Tuesday, June 3, 2008 - link

    I used the same motherboard and cpu, but I liquid cooled it using the gigantic Kandalf Liquid Cooled case. My memory is different as well since I use 4 GB of Patriot Viper memory (2 x 2GB). Other than the memory settings in the BIOS, I set everything to match this guide. My system runs at 4.0Ghz and the cpu runs at no more than 88 degrees fahrenheit even while playing something like Crysis with everything set to Very High. Crysis runs between 35 and 60 fps on Very High on my system using a single 9800 GX2 at 1280 x 720. It's a HTPC connected to my older 56 inch DLP set via DVI, so I can't go any higher than that, but I fully expect to run great at 1080p when I get my new large screen set later this year. I don't have my bios settings in front of me, but setting everything to Auto for the memory works PERECTLY at 4.0 ghz. Pretty cool. I think it's running at 8,8,18 or so and 1.9v.

    Also, Asus just released a patch to the bios that fixes the data corruption issue mentioned in this artcle. Released on 5/29/08 I think.
  • hardist - Monday, April 21, 2008 - link

    The water block seems to have leaking issues , I am wondering why it was not covered in this review since it is a major feature of this board ...... Reply
  • Heatlesssun - Sunday, April 20, 2008 - link

    This is a sweet motherbaord! Now I've not overclocked the FSB, just bumped up the multiplier of my QX9650 from the default of 9.5 to 10, and I'm not running RAID. We shall see but I feel good. To get this up and running with Vista x64 in a day so smoothly was pretty good I thought. Reply
  • electricx - Tuesday, April 15, 2008 - link

    So this board is going for the aforementioned amount on newegg... The EVGA and the XFX 790i boards are going for $350... The ROG name carries that much of a premium? I mean, come on?! I'm sure ASUS will fix this data corruption issue and you typically do pay more for the privilege(?) of being a beta tester for high end hardware but $1000 over competing products seems a bit much... The EVGA board is looking to be a clear winner here to me. Time will tell I suppose. Reply
  • FightingEagle - Friday, April 18, 2008 - link

    After the second EVGA 790i and full of bugs I just sent it back. I was interested in the ASUS X48 and the 790i, but the 790i over $400 is hard to grasp. EVGA has good looking heat sink but not very good at cooling. I may wait for all the bugs to leave but as now im sitting on $320 dollars worth of DDR3 and a E8400. Reply
  • electricx - Tuesday, April 15, 2008 - link

    Edit: That should have been $100 not $1000 Reply
  • UK1Man - Sunday, April 13, 2008 - link

    Help please!!
    I'm currently in the process of building a computer but can only afford to buy a couple of parts a month, I have already purchased some DDR2 (1066) memory for an FXF 780 motherboard (not yet purchased) but am now considering the Asus striker II extreme.
    Will my DDR 2 memory work with this?
  • seamusmc - Monday, April 14, 2008 - link

    This board/chipset, 790i, only supports DDR3. Reply
  • ianken - Saturday, April 12, 2008 - link

    Can it go into S3 suspend and come back out and have the NICs still work? The Striker 2 Formula cannot.

    Can the SATA controller handle hot swap? The Stiker 2 Formula and the previous 680i boards could not. The 680i bios even had an esata setting that did NOTHING.

    The latest crop of Asus boards, particularly the NV chipset rigs, have been pretty buggy and basic functionality has been borked.

    But hey, who cares of the basics don't work right? it's got a water block for X-TREME OVERCLOXORS! YO! VTEC!

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