Complete BIOS Tuning Guide - "Extreme Tweaker"

This guide's intent is to help those with limited overclocking experience or those unfamiliar with NVIDIA-based motherboards in learning the basics when it comes to overclocking DDR3 memory using the 790i MCP. All of these options can be directly accessed from the main BIOS setup page entitled "Extreme Tweaker" or from one of the four submenus listed below.

Extreme Tweaker

CPU Level Up - [Auto, Crazy] Selecting Auto, our recommended setting, allows for user adjustments of each individual CPU and memory overclock option (when available). If anything other than Auto is used the only overclocking option that can be manipulated is CPU Multiplier.

Crazy automatically sets AI Overclock Tuner to CPU Level Up, locks the FSB to the next higher tier based on the installed CPU's default value (333MHz goes to 400MHz, 400MHz is slightly increased to 433MHz etc.) and sets whatever DRAM:FSB ratio is needed to keep the memory running at DDR3-1333.

Memory Level Up - [Auto, PC3-11600, PC3-12800, PC3-14400, PC3-16000, PC3-16800, PC3-17600, Crazy-19200] Choosing anything other than Auto unlinks the base memory frequency from the FSB and sets the memory speed as selected. To find the actual base memory speed for each option simply divide the selection by eight (8) - for instance, PC3-14400 becomes DDR3-1800, which is just a way of referring to the memory's theoretical maximum bandwidth (14,400 MB/s or 14.4GB/s). This option is best left on Auto as the memory can be better tuned manually.

AI Overclock Tuner - [Manual, Auto, Standard, AI Overclock, CPU Level Up] Selecting Manual allows for individual adjustment of all CPU and memory overclocking parameters and is our recommended method for overclocking.

Auto locks the FSB frequency to the CPU's default value and sets DDR3-1333 for the memory speed. For most 45nm processors this means the memory then runs at a DRAM:FSB ratio of 2:1, standard practice for DDR3 motherboards. One exception to this rule would be the QX9770 working at a default FSB of 400MHz, in which case a 6:5 divider would be needed for DDR3-1333 memory operation. CPU Multiplier is the only other possible overclocking adjustment when using this option.

Standard is much like Auto in that the board automatically sets the FSB and memory speeds and only allows for CPU Multiplier manipulation. Essentially, these two settings performed the same during the course of our testing, implying that Standard, better known as stock, is in fact the default (automatic) setting.

AI Overclock enables Overclock Options, allowing the user to select one of four pre-defined overclocking "profiles", establishing a new FSB frequency. The memory and FSB memory speeds are linked and FSB - Memory Ratio (DRAM:FSB) can be adjusted along with CPU Multiplier.

The last option, CPU Level Up, functions differently based on the current value of FSB - Memory Clock Mode. If set to "Auto" or "Linked" then this option is almost exactly the same as choosing "Crazy" from CPU Level Up, except that the FSB is initially set to the installed CPU's default value. Setting FSB - Memory Clock Mode to "Unlinked" provides the ultimate freedom with respect CPU and memory overclocking - by effectively unlinking these two system clocks the FSB can be set independently from the memory frequency. Although the goal is that these two clocks remain completely autonomous in their operation, the chipset is not actually infinitely adjustable in this regard - it is entirely possible to find the actual memory speed set a little lower than the target speed, depending on the values selected for each.

Our experience has shown that instead of the relatively small number of "dividers" possible with Intel chipsets, NVIDIA's "unlinked" chipsets essentially provide 2^8 (256) dividers with some of the ratios at least achievable in theory sometimes falling outside of the range of possible memory speeds, depending on the FSB. This is usually enough to create the illusion of a fully unlinked FSB - Memory Ratio even though this is not really the case.

Overclock Options - [Disabled, Overclock 5%, Overclock 10%, Overclock 15%, Overclock 20%] This option is only available for adjustment when AI Overclock Tuner is set to "AI Overclock", otherwise it has no affect. The available settings - 5% to 20% overclock in 5% increments - refer to the target Front Side Bus (FSB) overclock, so CPUs with higher multipliers (as well as those with higher default FSB) will experience a more radical overclock than those with lower default values. For the most part, this is a poor overclocking strategy and we recommend you choose one of the more hands-on approaches if you are looking for real results.

CPU Multiplier - [6.0 to Default Multiplier, Fully Adjustable for Extreme CPUs] This value, when multiplied by the Front Side Bus (FSB), sets the CPU's core operating frequency. For instance, an 8x multiplier, combined with a 400MHz FSB frequency, results in a final CPU speed of 3.20GHz (8 x 400MHz = 3200Mhz).

All 45nm Core 2 Duo/Quad CPUs have multiplier options from 6.0x up to the value corresponding to the CPU's default operating frequency, in half-integer increments, excluding 6.5x. First-generation 65nm Core 2 Duo/Quads are the same, except that only integer multipliers can be used. For example, an E8400 CPU, which runs at 3.00GHz using a default FSB of 333MHz has a maximum multiplier of 9.0x (3000MHz / 333MHz = 9.0). This means that any of the following multipliers can be selected for use: 6.0x, 7.0x, 7.5x, 8.0x, 8.5x and 9.0x.

Processors with higher default operating frequencies will often have higher maximum multipliers, as long as the default FSB is not increased, in which case the default multiplier may in fact be lower in order to account for the higher bus speed - a good example of this is the QX9770 which uses a 400MHz default FSB speed. Calculating the default multiplier in the same manner shown above results in a value of just 8.0x (3200MHz / 400MHz = 8.0).

However, being an "Extreme" CPU, the QX9770 is capable of essentially unbounded adjustment when it comes to the multiplier - trust us, you will run out of operating margin long before you begin to explore the upper limits of these processors' multipliers. This makes owning an Extreme CPU particularly pleasant, as there is never any limitation on which multipliers can be selected for use. This is often referred to as having a CPU with an "unlocked" multiplier.

FSB - Memory Clock Mode - [Auto, Unlinked, Linked] For the most part, Auto is synonymous with Linked, meaning the DRAM:FSB ratio must be one of just a few fixed ratios. Unlinked means the user has the option of dialing in just about any FSB and DRAM frequency independent of one another. Maximum performance is achieved using the Linked mode of operation, something we will discuss in more detail later on.

Memory Write and Copy Performance Complete BIOS Tuning Guide - "Extreme Tweaker" (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!

Log in

Don't have an account? Sign up now