Shocking BIOS options

 

CPU VTT: Stock VTT voltage defaults to 1.17V or so. The scale runs in 10mv steps, allowing you to add or subtract from the base value. VTT voltage drives the integrated memory controller and the QPI link bus. This voltage will need to be increased as you increase memory frequency and increase BCLK (QPI frequency). Remember to keep this voltage within 0.5V of VDIMM to prevent damage to the integrated memory controller.

CPU PLL VCore: 1.8V base; we found no benefits to increasing this voltage for overclocking. Clean power to PLL circuits is essential for ensuring that external influences over the accuracy of clock signals is minimized. It seems EVGA have done a good job with regards to all PLL voltage rails on the Classified. In terms of overclocking headroom and PLL's, clean power always trumps more voltage, thus there's no need to tinker with these voltages to any great extent on this board, apart from perhaps QPI PLL. Even then, you'll probaby find the level of voltage required for maximum BCLK potential is far below what some other boards need to get the same clocks...

IOH PLL VCore: Input/Output Hub Phase Locked Loop voltage. The default voltage is 1.8V. For the most part this voltage can be left at stock unless chasing maximum QPI frequencies for benchmarking. For 24/7 use we recommend you stick with a maximum of 1.89V. Processors/IOHs needing more than 1.89V to remain stable are best run at a lower BCLK and higher CPU multiplier to bring them back into their comfort zone.

QPI PLL VCore: Quick Path Interconnect Phase Locked Loop voltage. For 24/7 overclocking this voltage can be left at stock in most instances. Again, if you need to use more it's probably wise to pull back a little on QPI frequency to a speed that requires no more than 1.2V. For benchmarking, we used 1.45V to reach 239 BCLK for a CPU-Z shot.

IOH VCore: Input/Output Hub voltage uses a 1.10V base. Stock values usually suffice for 24/7 overclocking even when using multiple graphics cards; we had no problems in reaching a stable 200 BCLK X20 for 4GHz CPU speed. For more extreme QPI frequencies this voltage will need to be increased. For 3D benchmarking past 220 BCLK we used 1.45V. We needed 1.50V to reach 239 BCLK. Values over 1.50V failed to POST or locked up in the OS; use only as much voltage as you need.

IOH/ICH I/O Voltage: IOH to Intel Southbridge termination voltage. We left this voltage at stock and did not see any overclocking improvements from increasing it on this board. Base value is 1.50V.

ICH VCore: 1.05V base voltage; again this voltage can be left at default.

NF200 Voltage: 1.2V stock. We left this voltage at stock for all overclocking.

VTT PWM Frequency: Changes the switching frequency of the VTT voltage line. Higher switching frequencies can help facilitate lower output ripple, and reduce overshoot while providing a higher frequency power bandwidth to the CPU. Setting a higher frequency with this BIOS option may improve overclocking headroom somewhat depending on the current drawn. For overclocking past 220 BCLK we generally used 490KHz; for speeds below this a 250KHz switching frequency worked fine for us and also reduces the heat output from the PWM FETs.

CPU PWM Frequency: CPU PWM (VCore supply) switching frequency. Stock is 800KHz, which is more than sufficient for 99% of overclocking. For subzero benchmarking you may wish to increase the switching frequency to see if it helps stability during heavy 8-thread CPU loads. The side effect in doing so is increased heat from the power FETs, although the temperature increase is quite small due to the use of a 10-phase power delivery circuit, especially as the FETs are indirectly cooled via the CPU power plane when the processor temperature is well into the negative region.

CPU Impedance: Sets the level of signal compensation for the QPI bus to the CPU. Higher QPI frequencies often demand a higher signal current, which means that compensation levels have to be changed in order to counter any signal line reflections caused by PCB traces and input impedance mismatches. The options available for this function are AUTO and Less. On the Classified, we found that QPI frequencies approaching 4GHz can benefit from a reduction in setting Less, even more so if the CPU frequency is well above 4.5GHz. Leave at AUTO for most 24/7 overclocking at BCLKs under 200MHz. For subzero cooling at high system speeds, set this value to Less to see if it helps with overclocking headroom.

QPI Compensation: Sets the level of signal compensation for the QPI bus to the IOH. There are three options for this function, those being AUTO, Less, and More. We found that IOH compensation is far more sensitive to changes in compensation values than the CPU. A setting of Less for high BCLKs and QPI frequencies almost always brings about additional system stability during benchmarking (at least in our experience). For all other purposes, this value can be left to AUTO.

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  • rogguy - Thursday, March 12, 2009 - link

    this board is mediocre compared to asus ROG
  • Everlong19 - Thursday, March 12, 2009 - link

    How can you have a triple GPU setup using dual slot cards and have room for a physics card/sound card?

    Only way it might be possible is putting the 3rd card in the 4th PCI-E slot, but that would overlap the USB headers etc. The PCI slot gets covered by the 2nd GPU, so any PCI sound cards can't go in there, either.
  • MadMan007 - Saturday, February 28, 2009 - link

    The important thing I take away from this preview has nothing to do with the board itself but rather eVGA's expanding custom software and software/hardware efforts. It's really neat to see a company like eVGA make a push in this direction going well beyond other mobo companies with their basic monitoring software and other graphics rebadgers.
  • MasonStorm - Saturday, February 28, 2009 - link

    You could certainly do it, as stated, by plugging one of the dual-slot cards into that last slot, and having it hang over the edge of the board - requiring an extra big case. But another way is to use liquid-cooled versions of the cards, cutting them all down to single-slot size. In any event, it doesn't matter where you place them, since you can use three of the soft, bendy SLI bridge connectors to make your own triple-SLI connection. You don't have to use anybody's firm, fixed triple-SLI connector. Just Google around to see how to use the three individual, soft, bendy connectors.
  • Casper42 - Friday, February 27, 2009 - link

    Question on this comment:
    The slot configuration allows running three dual slot GPUs and a single slot PhysX card or other PCI-E peripheral

    In looking at the pictures, this board only has 7 slots total with the x1 being at the top.
    If you used 3 Dual Slot GPUs, that would be 3 x 2 = 6 + the x1 = 7
    So where exactly are you putting a PhysX card?

    The only possibility I see is if you use an 8 or 10 slot Case and stick the 3rd Dual Slot GPU in the very bottom slot such that it hangs off the bottom of the mobo. But in this case, the normal 6 connector Triple SLI Bridge wont reach the 3rd card.

    Am I missing something here?


    PS: Dont get me wrong, I like the design of the board.
  • Rajinder Gill - Friday, February 27, 2009 - link

    You are right the 3rd SLI card would go in the last PCIe slot, with a dual card overhanging. An SLI bridge supporting this will ship with the retail board.

    Board dimensions are 310mmX265mm btw. Big case territory.

    regards
    Raja
  • cesthree - Friday, February 27, 2009 - link

    Remember the awesome 7X0i series of motherboards? Especially the last one with the NF200 on it? It's called a 790i "Ultra" chipset.

    There are only a few people who ever had problems with the 7X0i series motherboards when using multiple GPU's. Not one person ever complained about things like "freezing" or "hard locking" or "data corruption." Especially not at stock speeds.

    Just like there is absolutely no sarcasm in my last paragraph.

    What fool would by the "Classified" EVGA motherboard? It's got negligible performance increases. Why go through that much trouble for all of the 5 people on earth who would purchase it and use it with 3-4 GPU's + 30" or bigger monitor.

    Mark my words. The NF200 addition to the X58 that EVGA already had going GREAT for them, will bring them problems on the level with the last batch of shoddy, Nvidia tainted motherboards.

    I am going to put this in all my sigs from now on:

    "Nvidia, for the love of god, please stop crippling motherboards and just stick to GPU's."
  • Von Matrices - Friday, February 27, 2009 - link

    From what I can tell from sources online, the NF200 bridges 16 PCIe 1.1 lanes to 32 PCIe 2.0 lanes. What is there to gain by using the NF200 over just using four PCIe x8 2.0 lanes of bandwidth from the IOH? With the NF200, you get ~4GB/s bandwidth to the IOH per graphics slot compared to ~8GB/s with a native solution, and the bridge adds additional latency, which further reduces performance, and additional cost. Why would EVGA use it then? Are there any advantages to it?
  • Zak - Friday, February 27, 2009 - link

    Question. 920 can be easily o/clocked on most boards to 4GHz and peak under 80C under full load using a good air cooler and be perfectly stable. But how long will that CPU and mobo last at these temps and bumped up voltages if used daily? The temps can be addressed by water cooling but how damaging is running CPU at 1.4V, QPI at 1.5V/7.2GHz for long time?

    Z.
  • Agoniesfury - Saturday, January 23, 2010 - link

    Well I can testify to this comment, and say that I'm an enthusiast and like to buy top rated tech and push their limits, over 8 months ago I purchased a R2E to be used with my 1yr old 920 only bad part was the 920 was a C0 but nonetheless I was able to get to 4.1ghz for benching and everyday stablity "non prime stable", which did fine until 2weeks ago when the board just blinked at me and nothing more, well thank god for rma! So I did decide to upgrade to a classified 760, well in my case I lost some of the bells and whistles that the asus had but was better greeted with the hardware imporvements and design of the evga has. I'm now at 4ghz and climbing 8hrs+ prime stable where as the r2e only was prime stable up to 3.6. So I think both boards are great but the classy is a hair better and hope it lasts!
    P.S. I've been overclocing for about 10yrs and I never had a chip fry on me it's always the mobo from decay I asume, and the 920 it's self has been through 2 powersupplies and three mobo's.

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