Test Setup -


We utilized a wide variety of memory kits from Corsair, OCZ, Patriot, GSkill, Kingston, and Super Talent to verify memory compatibility on our test boards. Our OS and primary applications were loaded on the Kingston 80GB SSD drive and our games were operated off the WD 300GB VRaptor drive. We did a clean install of the OS and applications for each motherboard.

We chose the ASUS GTX275 video card and Corsair’s 750HX power supply. Our air cooler of choice is Thermalright’s Ultra 120 eXtreme, primarily for its exceptional performance during our overclocking tests. We also tested with the retail cooler and those results along with direct CPU comparisons can be found here.

Our 790FX/X58 results are provided for comparison only. For our test results we setup each board as closely as possible in regards to memory timings. Otherwise all other settings are left on auto. The P55 and 790FX motherboards utilized 8GB of DDR3, while the X58 platform contained 6GB. The P55 and X58 DDR3 timings were set to 7-7-7-20 1T at DDR3-1600 for the i7/920, i7/870, and i7/860 processors at both stock and overclocked CPU settings.

We used DDR3-1333 6-6-6-18 1T timings for the i5/750 stock setup as DDR3-1600 is not natively supported in current BIOS releases for this processor at a stock Bclk setting of 133. We had early BIOS releases that offered the native 1600 setting but stability was a serious problem and support was pulled for the time being. Performance is essentially the same between the two settings.

The AMD 790FX setup is slightly different as trying to run DDR3-1600 at CAS 7 timings on the 1:4 divider is extremely difficult. Without resorting to some serious overvolting and relaxing of sub-timings, we set our AMD board up at DDR3-1600 8-8-8-20 1T timings but with NB speed at 2200. The difference in performance between C7 and C8 DDR3-1600 is practically immeasurable in applications and games on this platform.

Overclocking Power Consumption
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  • MadMan007 - Sunday, October 11, 2009 - link

    The lack of information regarding PCIe slot assignment when different slots are populated has been SORELY missing from all P55 mobo reviews. It's either laziness or an attempt to cover up shortcomings but it seems pretty important to me - people actually expect to use slots that are present on the board, ya know?

    I STILL haven't seen an answer to how many lanes the primary graphics slot keeps when the secondary graphics slot is populated with a 1x or 4x card! This affects anyone who has a graphics card and sound card, or TV tuner, or disk controller and given the layout of many boards you're likely going to have to use the secondary graphics slot for those devices.

    I am also bothered by the lack of C2Q benchmarks. Loads of people have them and asking whether i5 in particular is a worthwhile upgrade is being ignored.
  • crab nebula - Tuesday, October 13, 2009 - link

    There are two kinds of P55 mbs:

    1. Non SLI: The PCI Express 2.0 x16 link does not split.
    2. SLI x8: The PCI Express 2.0 link splits into two x8 links, usually SLI-certified by NVIDIA
    3. SLI x16: The nForce 200 chip is equipped for 2-way SLI: x16, x16 and 3-way SLI: x16, x8, x8.

    Most mb of the first type also have a second PCI Express x16 slot which is connected to P55 and works at x4 (1.x in bandwidth).

    MSI P55-GD65 is of the second type. If you insert a PCI Express device (of whatever lanes) in the second PCI Express x16 2.0 slot (electrically x8), the first PCI Express x16 2.0 slot also works only at x8.

    A problem of P55-GD65 is that the severe (?) limitation of the PCI Express x4 slot is not mentioned in its product page or the manual at all. For example, suppose that a user is using a PCIe x1 sound card in the first PCIe x1 slot and a 2-slot graphics card. If he wants to use a PCIe x1 TV tuner card and insert it in the PCIe x4 slot, then he will suddenly find that his sound card stops working! So he has to use the second PCI Express 2.0 x16 for the TV tuner. Then this decreases the speed of the graphic card to x8!! Although practically this is not a big issue, this limitation still should be mentioned somewhere in the product page or the manual.

    "the layout of this board is just fantastic, especially the PCIe/PCI layout." ?? It looks like Gary Key is simply ignorant of this. ASUS and ASRock mbs have much better board layouts in this respect: all expansion slots actually work!
  • MadMan007 - Tuesday, October 13, 2009 - link

    Exactly the type of scenario that no mobo reviews have mentioned and which I was thinking of. Thank you for spelling it out.
  • crab nebula - Tuesday, October 13, 2009 - link

    Correction: "There are two kinds of P55 mbs" has to be "There are three kinds of P55 mbs". (The fourth type would be those that use Lucid Hydra 200.)
  • lopri - Sunday, October 11, 2009 - link

    I don't know how you don't see PCI Express slot information from the reviews so far? They have been clearly explained or are in the board specification page. There was even a special article regarding P55 chipset PCI Express.
  • MadMan007 - Monday, October 12, 2009 - link

    You need to reread and comprehend my post. I'm not asking for specs, obviously those are easy to find, but how lanes get assigned when slots are occupied especially with something other than a graphics card. I guess all reviewers are too lazy to put anything but one or two graphics cards in their test mobos.
  • lopri - Monday, October 12, 2009 - link

    I didn't go back and re-read the reviews, but at the time when I read them I was able to tell how the lanes are assigned on a given board. It's not like there are multitude of choices available.. All P55 boards so far (maybe except the one w/ NF200) support either a x16 lane or two x8 lanes from the CPU. Everything else belongs to the PCH and if I remember correctly all reviews made it clear when a physical x16 slot (x4 electrically) belongs to the south bridge.
  • MadMan007 - Monday, October 12, 2009 - link

    You still fail to comprehend and say it like I'm a moron who can't read a chipset diagram but your other link at least answered the question about the CPU-based lanes.
  • lopri - Monday, October 12, 2009 - link

    http://www.anandtech.com/mb/showdoc.aspx?i=3649">http://www.anandtech.com/mb/showdoc.aspx?i=3649

    quote:

    We are also reporting single card results with the HD 5870 running at PCIe 2.0 x8 speeds on the P55 platform to compare performance to the x16 single card setup. We installed an Intel CT Gigabit network card in the second physical x16 slot in order to force x8 operation.
  • MadMan007 - Monday, October 12, 2009 - link

    That is a video card review so no it's not been spelled out in mobo reviews. It's what I figured but hoped the lane splitter chips might be smarter. Thanks for the link though.

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