Overclocking: Winfast 755FXK8AA


Front Side Bus Overclocking Testbed
Default Voltage
Processor: Athlon 64 4000+
(2.4GHz, 1MB Cache)
CPU Voltage: 1.50V (default 1.50V)
Cooling: Thermaltake Silent Boost K8 Heatsink/Fan
Power Supply: OCZ Power Stream 520W
Memory: OCZ PC3200 EL Platinum Rev. 2
(Samsung TCCD Memory Chips)
Hard Drive: Maxtor 160GB 7200RPM SATA 8MB Cache
Maximum OC:
(Standard Ratio)
221x12 (5x HT, 2-2-3-10)
2652MHz (+11%)
Maximum FSB:
(Lower Ratio)
233* x 11 (2563MHz) (5x HT)
(1:1 Memory, 2 DIMMs in DC mode)
(+17% Bus Overclock)
*We were able to set overclocks as high as 300 FSB, but measurement of the true Clock Frequency indicated the highest setting for the board is 233. Foxconn has confirmed that 233 is the highest Clock frequency that can be run with the Clock Generator used in the Winfast 755FXK8AA.

At first, we were really excited that we could reach 300FSB with no vDIMM adjustments at all. However, several things did not make sense, and as we dug deeper, we discovered that the highest real speed we could achieve on the Winfast was 233 FSB. You can choose higher settings, but they are not real FSB overclocks. Foxconn did further testing on the 755FXK8AA and confirmed that the highest setting possible on this board is 233. Any higher settings would require an updated clock generator. Foxconn is looking at possible revisions to the Winfast, but 233 is the current OC limitation, and this will likely remain the case on this motherboard. Future redesigns of the board may bring additional FSB options.

It would be unfair to make too much of the 233 FSB limitation of the 755FX because that would overlook the incredible stability of the board at 233. At that overclock, the Winfast is completely stable. 233 is also a high enough overclock to confirm a working PCI/AGP lock. As you will see in the later performance data, the 755FXK8AA is very fast, so it makes you wish for more in the overclocking capabilities.
Basic Features: Winfast 755FXK8AA Memory Stress Testing
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  • ChineseDemocracyGNR - Tuesday, December 28, 2004 - link

    The SiS755FX adds 1000MHz HTT support. So it's a chipset for socket 939 processors.

    The SiS756 is a new chipset, supporting PCI-E graphics.
  • RAINFIRE - Sunday, December 26, 2004 - link

    I wasn just wondering if the SiS 756 is replacing the 755FX chipset. This seems to be the case with me. Anyone know if this is what is happening?
  • RAINFIRE - Sunday, December 26, 2004 - link

    I was just wondering if the SiS 756 chip is better/replacing the 755FX. This seems to be the case as far as I can see. Any thoughts, conments on that? I've been keeping a Next Gen Motherboard list and want to get it right.
  • Cygni - Sunday, December 19, 2004 - link

    The 755 had solid performance and i was very surprised that more board makers didnt use it. The 755FX/756 seems to be another step in that direction. Realistically, because the Nforce4 and ATI Xpress 200 are STILL not on the market, it is still possible for the 756 to be the first PCI-Ex capable AMD chipset.
  • ChineseDemocracyGNR - Friday, December 17, 2004 - link

    Yes, the board is available here:
    http://www.newegg.com/app/ViewProductDesc.asp?desc...

    Price is $101. The Foxconn is $69, the ASRock is $77 but it has overclocking options (the Gigabyte doesn't).
  • Peter - Friday, December 17, 2004 - link

    I've seen that ... they did actually go ahead and made it available WITH the dedicated VGA RAM? Good then. But at $30 more than the same thing in shared-RAM configuration, they've missed the price point ... I mean, $30 buys me an entire Xabre graphics card.
  • ChineseDemocracyGNR - Friday, December 17, 2004 - link

    #20, that is great news! Are you going to test the K8Upgrade-760GX (SiS760GX, mATX) or the K8Upgrade-1689 (ULI M1689, ATX)?

    #22, Gigabyte makes a board with dedicated memory. It does improve performance but it's considerably more expensive too (at least $30).
    There's a review:
    http://www.ocworkbench.com/2004/gigabyte/K8S760M/K...
  • Peter - Friday, December 17, 2004 - link

    Wesley, I wrote this _after_ reading the article ;) Head still on shoulders.

    SiS integrated video for the A64 platform looks particularly interesting because it can have dedicated (!) VGA RAM attached to the north bridge chip. This is because they left the RAM controller in there - exclusively for the integrated VGA this time, since the CPU brings its own.
    Now if only the board makers adopted that feature ... all I've seen so far (ASRock, ECS, PC-Chips) run it in shared-RAM mode, and so does my shiny new Averatec 5500 notebook. History repeating - even back in the Pentium and early PII days, the integrated SiS chipsets (530, 620, 630) supported dedicated VGA RAM, but practically nobody made boards that used it.

    As for clock synthesizer chips, well if this piece of hardware doesn't support what you want it to do, then no update of BIOS or other software will make it.

  • Calin - Friday, December 17, 2004 - link

    #17, I would like to have an Athlon64 board with integrated video... but not with SiS integrated video. I would wait until (hopefully) some ATI-based board appears here in Romania. (I know I might be wrong about not buying a SIS with integrated video, but I prefer not to take the chance)

    Calin
  • Wesley Fink - Thursday, December 16, 2004 - link

    #17 - We have been talking with Asrock, and we will be reviewing a ASRock K8Upgrade, and the upgrade module, which is based on the SiS 760GX. We also requested a ULI chipset board but we have not received any info yet on when that board may be available for review.

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