The not-so-good stuff
You're probably all ready to sign up for the SMP brigades now that you've read about all the good things the Tiger MPX can do. Simmer down, though, and get a load of the downsides first. The 760MPX comes with a host of "gotchas." They're not necessarily dealbreakers, but they are annoying.

First, AMD didn't design the 762 memory controller to work with regular old unbuffered DIMMs. Instead, the 762 usually requires registered DIMMs. If you're like me, that means you can't just transplant your DDR DIMMs from your previous motherboard when upgrading. Frustrating.

Fortunately, Tyan has made substantial improvements to the Tiger MPX's memory handling. Now, unlike the Tiger MP, the Tiger MPX can make use of unbuffered DIMMs in memory slots one and two. If you want to use more than two DIMM slots, though, Tyan recommends registered DIMMs still.

Next, there's the Tiger MPX's tweaking options. The juiciest screen in the whole BIOS looks like this:

Not exactly chock full of overclocking options

..and that's about it. You can't tweak the RAM timings, can't juice up the CPU voltage, can't change a single default clock frequency or multiplier.

If you look at it wrong, a big, electronic hand will reach out of the screen and grab you by the collar while the motherboard chastises you for even thinking about overclocking. This is a serious computer, fool!

Even switching from a 200MHz to 266MHz front-side bus doesn't happen in the BIOS or via CPU auto detection. Instead, you've gotta move a total of four different jumpers on the motherboard in order to make this change. Other FSB frequencies are not offered.

What's more, Tyan won't officially sanction running a pair of Durons or Athlon XPs; the board only supports Athlon MPs in dual configurations. (No doubt AMD had some say in this one.)

Then there's the USB problem. Thanks to a bug in AMD's 768 south bridge chip, all AMD 760MPX motherboards currently have a broken USB controller. Tyan says it will make a version of the Tiger MPX with working USB ports just as soon as AMD fixes the 768 chip. However, I've seen no indication that current Tiger MPX owners will be eligible for replacement boards. To compensate, Tyan includes a four-port USB controller card with the Tiger MPX. Unfortunately, the card is a USB 1.1 controller, not a USB 2.0 card like those included with some of the Tiger MPX's competitors.

All of which leads to...

The quandary
The USB problem is worse than it seems at first, because the USB card will occupy one of the Tiger MPX's four 32-bit/33MHz PCI slots. The two 66MHz/64-bit PCI slots on the Tiger MPX, meanwhile, aren't compatible with the vast majority of PCI expansion cards out there. (The older Tiger MP could accommodate regular old 32-bit PCI cards in its 64-bit slots, but the Tiger MPX's 66MHz PCI bus makes those slots incompatible.) Now, if you need 66MHz/64-bit PCI for a high-end SCSI RAID controller card or something like that, those 66MHz PCI slots are great. But for most folks, at the end of the day, what you're getting with the Tiger MPX is three open PCI slots.

Without on-board RAID or built-in sound, those three open PCI slots are gonna get filled up quick. If it were my own system, for instance, I'd probably drop in a sound card, a Firewire card, and an IDE RAID controller. Assuming that IDE RAID controller isn't compatible with 66MHz PCI, that's the end of the road. If you want to add a TV tuner card or most anything else, you're pretty much out of luck. Thank goodness the Tiger MPX includes a decent on-board NIC, or the PCI slot situation would be nearly impossible for most of us.

This mess makes the original Tiger MP look mighty attractive by comparison. If you don't mind buying registered DIMMs, the Tiger MP will give you working USB and six PCI slots. (Yep, those 64-bit/33MHz slots on the Tiger MP will accept 32-bit/33MHz cards, as well.) Depending on your needs, the Tiger MP may be a better option than the MPX.