Between the two
PCI Express x16 slots is what ECS calls its "Elite Bus
Slot" which allows the PF88 Extreme Hybrid to essentially morph into another motherboard entirely.
To enable the bus however, you must move two sets of eight jumpers.
This is not difficult, but make sure you do not lose one of
the small jumpers otherwise you're in trouble; they are not standard size.
I hope ECS includes spare jumpers with
retail motherboards because I can see many users losing track of them.
According to ECS, the Elite Bus Slot actually runs
through the PCI Express x16 interface. This makes sense since a PCI Express x16 slot
has up to 8GB/s worth of bandwidth available; plenty for an Athlon64.
The individual SIMA cards will retail for approximately $50 US which is pretty
reasonable compared to the price of your average motherboard. At the moment the
only SIMA card that is available is the A9S model which uses the SIS
765 chipset and supports Socket 939 Athlon 64s. Others will be available soon
for pretty much every other platform including Socket 478 Pentium 4,
Socket 479 Pentium M and Socket 754 Athlon64/Sempron processors. The A9S SIMA card supports all
current Socket 939 Athlon64 processors as well as upcoming dual core Athlon64
X2's, but the latter requires a BIOS update.
Because of the obvious space constraints, there
are only two DDR RAM DIMM slots available for use on the A9S SIMA card, meaning
that users will be limited to 2GB of system memory total. To the right of
the DIMM slots you'll see a four pin ATX12V connector. When using the SIMA
card you must direct the extra 12V connector there.
Again due to space limitations, installation
of large after-market coolers will be difficult or impossible if you want to
also use dual channel memory on the A9S SIMA card. We noticed that even our
stock Athlon64 4000+ heatsink was too wide for the SIMA card and we had to go with
a cooler that was a bit slimmer. Also, don't be surprised if Athlon64
temperatures are higher than expected. Even though the onboard Intel SiS 656
Northbridge is disabled, it still produces a lot of heat as does the system
On the back of the SIMA card we find the the
SiS 756 Athlon64 Northbridge along with its small passive heatsink.
Traditionally SiS chipsets run quite cool but the ones found on the PF88 Extreme
Hybrid and the A9S SIMA card run very hot!
As you probably noticed, the PF88 Extreme
Hybrid motherboard has two PCI Express x16 slots. When using the motherboard
alone (without a SIMA card) you are only able to use the first PCI Express x16
slot. The second is disabled and will not function even if a card has been
inserted. With the SIMA card installed, access to the first PCI-E x16 slot is
blocked, so the second slot is enabled.