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The Perils Of Overclocking

P55 On A Budget: Five Core i5/i7 Motherboards For $100-$150
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This editor has been using 1.45 V to overclock ever since Intel’s 45nm Wolfdale cores were introduced. So far, we haven’t incurred any CPU damage as the result of voltage alone, though a certain Core i7 motherboard failed repeatedly from high VRM stress and eventually killed a CPU. But these are the new, more efficient motherboards, so we certainly should not see that mess again…right?

Unfortunately, the same brand of board that failed three times before failed again, was replaced, and failed a second time at the same transistor while using a “gentler” 1.40V. But this time ASRock wasn’t alone.

ECS’ P55H-A blew out what appears to be capacitors and didn’t even shut off afterward. We shut it down manually and the system still runs on two power phases, though we wouldn’t want to stress it. ECS’ failure occurred at the 0.29 V core voltage offset, which produced core voltage levels from 1.39 to 1.41 V depending on load.

The third try is supposed to be charmed, but it wasn’t for MSI. The P55-CD53 blew out one power phase at a mere 1.36V under full CPU load. However, the circumstances surrounding that failure are a little more interesting, since a 0.371V offset voltage was required to get the system to boot at 1.44V, where the load of eight Prime95 threads pulled its voltage down to 1.36V. It stayed at 1.36V for several minutes before the failure occurred.

Whom do we go to for answers here? Encouraged by a far-lower TDP rating on the new generation of Core i7 processors (95W, down from 130W), these companies probably designed LGA 1156-based models with a similar percentage of “overcapacity” as they’d used on LGA 1366 boards. But the fault doesn’t sit solely with each motherboard’s initial design team, as testing should have revealed the problem before the boards reached mass production or distribution.

Maybe a better question would be “what’s missing”? It seems that many of our previous-generation motherboards would shut off when overloaded, before anything was damaged. That’s called over-current protection, and it’s a feature apparently now reserved for high-end boards.

But did we push too hard? Remember that these settings were achieved using air cooling while keeping the CPU below its thermal-throttle threshold. Air-cooled overclocks certainly aren’t considered “extreme.” And for those wondering, the side of the VRM that burned in every case was the same side upon which the CPU fan was blowing strongly. This once again demonstrates that a voltage regulator should never be designed so that it can output more than its peak capacity.

Because three of the failures occurred at or below 1.40V, we have no knowledge of what to recommend as a “maximum safe” voltage for overclocking these three motherboard models. In the future, we’ll allow motherboard manufacturers to specify any lower “maximum” settings that may be required to preserve their products and will then duly arm readers with that information.

Update: ASRock confirmed that its P55 Pro was designed to handle a smaller power load, based on Intel's lower TDP for LGA 1156 processors, and has sent a BIOS its representatives claim will enable built-in over-current protection. To make sure that all three companies have an equal opportunity to address this issue, we have given them all two weeks to come up with a solution and will publish an article that addresses the new overclocking limitations.

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  • 0 Hide
    dirtmountain , October 8, 2009 7:05 AM
    The Asrock P55 Pro is 16x-4x, not 8x-8x.
    http://www.asrock.com/mb/overview.asp?Model=P55%20Pro
    http://www.newegg.com/Product/Product.aspx?Item=N82E16813157171
    The Asrock P55 Extreme at $140 offers 8x-8x
  • 4 Hide
    JeanLuc , October 8, 2009 8:44 AM
    Good read but it really just confirms what a lot of us have known for a long time. Don't buy budget motherboards (MSI, ASrock, ECS) if you want to overclock and it's no coincidence that the boards from Gigabyte and Asus passed with flying colours as these companies clearly have proper testing procedures in place and quality assurance measures to avoid such issues.
  • 0 Hide
    evongugg , October 8, 2009 11:29 AM
    Another great article from Tom's, letting us know about how one of these motherboards can burn your CPU. Never would have known without you.
    Might have burnt out a CPU and not know the cause.

  • -4 Hide
    Crydee , October 8, 2009 12:06 PM
    How would P55 stack up against non P55s is what I wanted to see as well. See if the premium is worth it over the more budget friendly P55.
  • 0 Hide
    LATTEH , October 8, 2009 1:01 PM
    nice article i liked it!
  • 0 Hide
    avatar_raq , October 8, 2009 1:26 PM
    Unfortunately neither Gigabbyte nor ASUS boards offer the 8x8x PCI-e slots for multiple GPUs. I think it's better to wait for their premium brethren to fall below $150 before upgrading.
  • 1 Hide
    SchizoFrog , October 8, 2009 1:52 PM
    For the extra $20 you can get the ASUS P7P55D PRO which is a much better board and offers the full spec for multi GPUs... However, I personally can only recommend what I would do myself and that is to wait. There are a lot of major PC spec changes over the next 6 months. So I am waiting for USB3 and SATA3 to make it to mainstream.
  • -4 Hide
    SchizoFrog , October 8, 2009 1:52 PM
    For the extra $20 you can get the ASUS P7P55D PRO which is a much better board and offers the full spec for multi GPUs... However, I personally can only recommend what I would do myself and that is to wait. There are a lot of major PC spec changes over the next 6 months. So I am waiting for USB3 and SATA3 to make it to mainstream.
  • -4 Hide
    helms , October 8, 2009 1:54 PM
    I doubt their quality assurance is as good as you think Jeanluc. Both Gigabyte and Asus make crap DDR3 controllers for socket 775 motherboards. I've tested a heap of DDR3 socket 775 boards from Asus and Gigabyte, the Asus P5Q3 in particular is causing a lot of problems. When paired with a quad core cpu (everything stock) and running 3 threads prime(blend) + furmark, the system would inevitably freeze in under 2hr's (usually within the 30 minutes mark, quite a bit less than 2hrs). In fact systems with those boards would freeze even during normal non PC intensive use such as browsing the internet. Running prime+furmark just forces it happen rather than waiting for it to freeze which is quite random during light use like word prcoessing. I doubt Asus even realizes that their P5Q3 is a faulty product and shouldn't have hit retail stores. They have been selling the P5Q3 for ages. They probably tested the board with a cheap dual core celeron and since it worked with that called it a day.
  • 0 Hide
    burnley14 , October 8, 2009 2:18 PM
    JeanlucGood read but it really just confirms what a lot of us have known for a long time. Don't buy budget motherboards (MSI, ASrock, ECS) if you want to overclock and it's no coincidence that the boards from Gigabyte and Asus passed with flying colours as these companies clearly have proper testing procedures in place and quality assurance measures to avoid such issues.


    I think you're jumping to conclusions here. Tom's reviewed some boards a while back for the 1366 socket and gave ASRock first place for quality and value.
  • 0 Hide
    avatar_raq , October 8, 2009 2:24 PM
    @ schizofrog :
    Yeah and the GIGABYTE GA-P55-UD4P is priced similarly and sports 8x8x configuration and more SATA ports.
    I believe well-featured P55 mobos are still expensive for the mainstream market.
  • -2 Hide
    oldscotch , October 8, 2009 2:35 PM
    Still getting two or three PCI slots on these new boards. I can see one, and I realize they're budget boards - but still. I'd much rather see some more x4 PCI-e or even just x1 options that would give graphics cards some breathing room.
  • 3 Hide
    Crashman , October 8, 2009 3:00 PM
    helmsI doubt their quality assurance is as good as you think Jeanluc. Both Gigabyte and Asus make crap DDR3 controllers for socket 775 motherboards.


    Intel made the memory controllers on Asus and Gigabyte P45/X48 motherboards. If it fails after two hours, there's a chance you're using inferior-quality memory.
  • -1 Hide
    Crashman , October 8, 2009 3:03 PM
    oldscotchStill getting two or three PCI slots on these new boards. I can see one, and I realize they're budget boards - but still. I'd much rather see some more x4 PCI-e or even just x1 options that would give graphics cards some breathing room.


    They're already using up all the PCIe lanes, when they put a second x16 slot on a board and feed it with four of the P55's eight. Sorry, the P55 isn't designed to support a buch of high-bandwidth slots, that's what the X58's for.
  • 1 Hide
    alexie , October 8, 2009 3:09 PM
    My question is
    "will there be a chipset made by Nvidia for 1366 socket or 1156 socket intel cpus?"
    Cause Nvidia is making good chipsets with both on-board VGA for mainstream and upper mainstream cpus.
  • 0 Hide
    ceteras , October 8, 2009 3:26 PM
    alexieMy question is"will there be a chipset made by Nvidia for 1366 socket or 1156 socket intel cpus?"Cause Nvidia is making good chipsets with both on-board VGA for mainstream and upper mainstream cpus.


    The answer is NO
  • 0 Hide
    murst , October 8, 2009 3:35 PM
    The ECS P55H-A has a power connector for the graphics card next to the pci express 16x slot. My graphics card ( Radeon 5850 ) already has 2 power connectors on it.

    Do all 3 power connectors need to be hooked up? Thanks!
  • -1 Hide
    lafanzy , October 8, 2009 3:44 PM
    Quite an irritating writeup I'd say. Sarcastic and vague comments with strong emphasis on avoidance in getting to the point. i like to call it bias, but, i haven't tested all the mobos myself. What do I get out of this article? How to kill a good article title in five.
  • 1 Hide
    ceteras , October 8, 2009 3:47 PM
    I wonder how cheap can they build a mainboard with no extra features (no overclocking support, no bells&whistles). Just the bare needed to keep the cpu working at it's default potential.
    I'd like one of these.
  • 2 Hide
    Sunburn74 , October 8, 2009 4:05 PM
    Hey, can you guys start testing if S3 sleep is maintained at high overclocks? Gigabyte board look great on paper, but the fact is something like 80-90% of them cannot S3 sleep once you start overclocking past a certain point. My next mobo has to be able to overclock and keep the sleep feature intact. It takes one sec to test. Please include it in the future. Thanks
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