SiS 755FX Chipset

The SiS 755 chipset was covered in detail in our review of the SiS 755 Reference board. The SiS 755 supported 800HT, Socket754, and single-channel memory. The 755FX takes the excellent features and performance of that chipset and updates it for Socket 939.

This means that the new 755FX supports 1000 HyperTransport speed, Socket 939, and dual-channel memory. Winfast combines the 755FX with the same 964 Southbridge used on the 755 Reference board. That means that this combination supports AGP8X, PCI, 4 IDE devices, and 2 native SATA ports.

Model Athlon 64FX
Athlon 64 (939)
Athlon 64FX
Athlon 64 (939)
Athlon 64 (754)
Pin Count 939 939 754
Memory Controller Dual Channel DDR Dual Channel DDR Single Channel DDR
Memory Type Unbuffered DDR400/333 Unbuffered DDR400/333 Unbuffered DDR400/333
HyperTransport 2000MT/s
Chipset SiS756/965 SiS755FX/964 SiS755/964
Graphic Interface PCI-EXP x16 AGP8X AGP8X

SiS has also announced a PCI Express chipset for Athlon 64, called the SiS 756. We have not seen a SiS 756 board yet, but the chipset specifications are basically the same as 755FX with support for PCI Express instead of AGP/PCI. The new 965 Southbridge announced with the 756 also supports 4 SATA 150 ports instead of the 2 SATA ports supported by 755/755FX.

Index Basic Features: Winfast 755FXK8AA
Comments Locked


View All Comments

  • 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:

    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:
  • 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)

  • 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.

Log in

Don't have an account? Sign up now