Overclocking - QX6700

EVGA 680i LT SLI
Quad Core Overclocking Testbed
Processor: Intel Core 2 Extreme QX6700
Quad Core, 2.66GHz, 8MB Unified Cache
1066FSB, 10x Multiplier
CPU Voltage: 1.4500V (default 1.3500V)
NB Voltage: 1.40V
FSB Voltage: 1.40V
Cooling: Tuniq 120 Air Cooling
Power Supply: OCZ ProXStream 1000W
Memory: OCZ Flex XLC PC2-6400 (2x1GB) (ProMOS Memory Chips)
Video Cards: 1 x MSI 8800GTX
Hard Drive: Western Digital 150GB 10,000RPM SATA 16MB Buffer
Case: Cooler Master CM Stacker 830
Maximum OC: 362x10 (3-4-3-9 2T, 797MHz, 2.20V), CPU 1.4500V
3625MHz (+36%)
Maximum FSB OC: 432x8 (3-4-3-9 2T, 798MHz, 2.20V), CPU 1.4500V
3460MHz (+62% FSB)
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Needless to say, quad core overclocking on the 680i platforms has been a huge disappointment until recently. There is a new hardware revision of the EVGA 680i board and the latest BIOS on the ASUS Striker now allows 400+ FSB operation. Our board reached a final 362FSB at the stock multiplier and this was a setting that we found to be very stable during testing. We were able to POST and enter XP at 368FSB but could not complete our benchmark testing. Once again, the lack of voltage options hindered our results but they are still very good.

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Click to enlarge

We dropped the multiplier on our QX6700 and were able to hit 8x450. The board completed the majority of our benchmarks at this setting but could not pass quad Prime95 or our four application multitasking test without the number three core waving the white flag. We finally reached a benchmark stable setting of 432FSB and probably could have gone higher but we had one of the dreaded FSB holes in the 440FSB range.

The one problem noted during testing is that we had to set our processor voltage to 1.4750V in order to maintain system stability. Our processor normally will run in the 3600MHz range at 1.4125V, and this was the highest voltage we have required on a board to reach this range. The reason for this is that Vdroop is terrible on this board with the quad core processor. We would see drops as high as .07V under load testing with the average drop being around .04V during game testing. The board also liked to "sing" to us while overclocked with the quad core installed. It was the one noise emitting from our case that we found to be louder than the chipset fans.

While we sound a bit pessimistic, this board did deliver results beyond our expectations in quad core testing. We just feel like a couple of the "corner cutting" activities inside the BIOS limited us once again from reaching the board's true capabilities.

Test Setup

Standard Test Bed
Performance Test Configuration
Processor: Intel Core 2 Duo E6600
(2.4GHz, 4MB Unified Cache)
RAM: OCZ Flex XLC PC2-6400 (2x1GB) 2.20V, 3-4-3-9 (1T where applicable)
(ProMOS Memory Chips)
Hard Drive: Western Digital 150GB 10,000RPM SATA 16MB Buffer
System Platform Drivers: Intel - 8.1.1.1010
NVIDIA - 9.35, 8.43
ATI - 6.10
Video Cards: 1 x MSI 8800GTX
Video Drivers: NVIDIA 97.92
CPU Cooling: Tuniq 120
Power Supply: OCZ ProXStream 1000W
Optical Drive: Plextor PX-760A
Case: Cooler Master CM Stacker 830
Motherboards: ASUS Striker Extreme (NVIDIA 680i) - BIOS 1002
ASUS P5N-E SLI (NVIDIA 650i) - BIOS 0401
ASUS P5B-E (Intel P965) - BIOS 0402
DFI LANParty UT ICFX3200-T2R/G (AMD RD600) - BIOS 12/22
EVGA 680i LT SLI (680i LT) - BIOS Award 721N0P01
GIGABYTE GA-N680SLI-DQ6 - BIOS F4B
Intel D975XBX2 (Intel 975X) - BIOS 2333
MSI P6N SLI Platinum (nForce 650i) - BIOS 1.22
Operating System: Windows XP Professional SP2
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A 2GB memory configuration is standard in our XP test beds as most enthusiasts are currently purchasing this amount of RAM. Our choice of mid-range OCZ Flex XLC PC-6400 memory represents an excellent balance of price and performance that offers a very wide range of memory settings during our stock and overclocked test runs. We also utilized our Corsair XMS2 Dominator (Twin2x2048-9136C5D) memory on this board to verify DDR2-1066 to DDR2-1200 compatibility with another memory type.

We are currently completing testing of several other memory modules ranging from Transcend, TwinMOS, and WINTEC DDR2-800 down to A-DATA DDR2-533 for compatibility and performance benchmarks in our roundup article. Our memory timings are set based upon determining the best memory bandwidth via MemTest86 and test application results for each board. We only optimize the four main memory settings with sub-timings remaining at Auto settings.

We are utilizing the MSI 8800GTX video card to ensure our 1280x1024 resolutions are not completely GPU bound for our motherboard test results. We did find in testing that applying a 4xAA/8xAF setting in most of today's latest games created a situation where the performance of the system at our standard resolution did not really change. Our video tests are run at 1280x1024 resolutions for this article at High Quality settings. We also tested at 1600x1200 and 1920x1200 4xAA/8xAF for our NVIDIA SLI results that will be presented in our next article.

All of our tests are run in an enclosed case with a dual optical/hard drive setup to reflect a moderately loaded system platform. Windows XP SP2 is fully updated and we load a clean drive image for each system to ensure driver conflicts are kept to a minimum. We were able to run our memory test modules at 3-4-3-9 1T for our benchmark results and will be updating the results of our other boards with 1T operation shortly.

Dual Core Overclocking Synthetic Performance Tests
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  • Stele - Wednesday, March 28, 2007 - link

    quote:

    Also, Jarred, or whomever else would like to answer, how hot does the PWM section of this motherboard run ? Seems lately, dual core on up motherboards tend to run hot in the PWM.


    It boils down to the engineering headroom put into the PWM design. Let's say the maximum supply current anticipated from a generation of CPUs is 50A (usually from datasheets and/or design guidelines from the CPU manufacturer). Motherboard designers can design their PWM to be just sufficient for this - most notably, the MOSFETs chosen may be those that can handle around 75A - or they can build some headroom in and choose MOSFETs capable of, say, 100A.

    The former design philosophy saves cost, and after all it gets the job done. However, since the components would be running near their design limit, they would generate quite a bit of heat... especially during spikes of load and/or when new CPUs with even higher current draw (e.g. quad-core CPUs) show up.

    The latter design philosophy is more expensive, but because the components would be running well below their rated spec, they fare much better in terms of thermal dissipation (and hence efficiency, as less power is lost as heat). The lower running temperatures also help improve the reliability of the components since less thermal stresses are present. Furthermore, when current loads increase - be it due to sudden load spikes and/or power-hungry CPUs and/or overclocking - they still have a lot of headroom, and so are able to handle the extra load without breaking a sweat. This results in better stability and again, lower heat dissipation compared to lower-spec'ed components at the same load.

    In view of this, perhaps one other area that Anandtech could look at when reviewing motherboards is to have an IR thermometer handy (the ones that you can point and measure temperatures of surfaces remotely with) and perhaps measure the temperatures of the chipset and PWM (or at least the temperatures of their heatsinks) at idle and load. It may not be perfect (especially when heatpiped, and a hotter heatsink could also mean that the heat flow from the component to the heatsink is good due to good thermal contact) but imho at least it would give a useful ballpark figure.
  • Stele - Wednesday, March 28, 2007 - link

    Pretty good review, critically assessing the chipset in light of theory (paper specs) as well as reality (actual value for money based on real-world prices and competiting products).

    IMHO, Nvidia's attempt to create a lower-cost version of the 680i SLI by limiting BIOS options and tossing the odd feature out (like passive chipset cooling and two USB/one network port) seems a little clumsy at best... Instead, I think the hybrid chipset combination used in, for example, the Asus P5N32-E SLI Plus is a more elegant solution. As this review demonstrated, the BIOS options do not necessarily cap the LT's overclocking capability enough to prevent it from being a threat to the 680i SLI's exclusive turf. Indeed, it might well turn out that the latter's sales would not be jeopardised by the LT anyway - not because of the arbitrarily imposed limitations, but because of the almost non-existent price difference between boards based on the two chipsets, considering the lost features.

    Meanwhile, other reviews of the P5N32-E SLI Plus have noted that the MCP used is that from the AMD-platform 590 SLI chipset. I wonder if, other than the slight rearrangement of PCI-Express lanes, there are any real differences (e.g. revised/improved networking/disk controller engines etc) between the two MCPs? Or are these blocks nothing more than carried over directly from the 590 SLI? It would be great if Anandtech could look into that.

    Lastly, a tiny note - it's a little amusing to note how it must be a bit pedantic to have to spell out the full name of the 'solid' capacitors used... at least Anandtech strives hard to get it right! :) Really, though, for the kind of 'solid' capacitors that we're talking about on most motherboards, "aluminium solid electrolytic capacitors" or even just "solid electrolytic capactitors" (vs. 'regular' (liquid) electrolytic) would do perfectly. Conductive polymer capacitors are generally (though not restricted to) the little rectangular ones such as the ones seen on Asus RoG boards as well as the P5N32-E SLI Plus. Just a thought :)
  • yyrkoon - Wednesday, March 28, 2007 - link

    Well, about the capacitors, I know as per some OEM, anandtech was calling them 'solid state capacitors', which you sound like you know enough about electronics to know this is wrong. Anyhow, several readers, including myself called 'foul', and there you have it . . .
  • JarredWalton - Wednesday, March 28, 2007 - link

    There were a few complaints when he used "solid capacitors", so I guess the full name is the safe way to go. LOL
  • Stele - Wednesday, March 28, 2007 - link

    Oh very true! "Solid capacitors" and "solid state capacitors" (as yyrkoon rightly commented) are both commonly used on many hardware sites, and are both inaccurate. One reason for the repeated complaints, iirc, is that we were simply oscillating between one inaccurate term and another. :P

    "Solid electrolytic capacitors"... now that is perfectly acceptable, despite a difference of one word. The devil, as they say, is in the details. ;)
  • yyrkoon - Wednesday, March 28, 2007 - link

    You did the right thing Jarred, you know how picky 'us' readers are ;)

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