Reference motherboards are interesting creatures.
Chipset manufacturers, such as VIA, SiS, ALi, NVIDIA, and ATI, all design actual
products to showcase their core logic technologies. Thus, the reference
boards are most often fully featured versions of what a third-party manufacturer
could do if they wanted to go all out. VIA's VT5798B is no exception -
every feature listed on the PT880 specification sheet is present and accounted
for, in addition to a few extras that aren't mentioned. That being said,
reference boards can be pretty quirky, especially since they aren't meant for
retail consumption. We've been testing two PT880 boards - one on the east
coast and another on the west - and it should be noted that the board used for
benchmarking failed to load Windows XP properly over any Serial ATA hard drive.
Consequently, we used an older IBM ATA-133 drive for testing.
Other than the slight Serial ATA glitch, our
reference board behaved well. It features four 184-DIMM slots for up to
8GB of DDR400 memory, and of course, a Socket 478 interface with full support
for an 800MHz front side bus. During VIA's visit, we inquired about proper
Prescott support, the code name for an upcoming revision to the Pentium 4
architecture. The VIA representative wasn't sure, mainly because Prescott
processors seem to be in particularly short supply, even to hardware vendors
designing the supporting infrastructure. So, it remains to be seen whether
Prescott will run flawlessly on PT880.
Layout is a bit of an issue for the PT880 reference
board. Hopefully, manufacturers opt to move the power connectors from
below the socket interface, where they are now, to the far right of the board to
aid in air circulation. Also, the board's lone parallel IDE connector lies
directly under the AGP slot. While we didn't encounter any problems with
our RADEON 9800 XT, a longer card could potentially necessitate some adjusting
of the IDE cable. Again, this is probably one area
where third-party manufacturers will choose to do a bit of redesigning.
Indeed, a quick
look at MSI's PT880 Neo-FISR reveals that both recommendations are being
The board's back panel gives a
pretty good indication of what the PT880 chipset can do. Beyond standard
PS/2, serial, and parallel ports, it boasts four USB 2.0 ports and two RJ-45
connectors, one of which interfaces with a VT6103 10/100 PHY, while the other
offers 10/100/1000 Gigabit Ethernet through the onboard VIA Velocity controller.
There are also two stacks of three, 1/8" analog mini-plugs for connecting eight
speakers, a microphone, and a line output.
A few words are in order for both
the integrated Ethernet and audio solutions. One reason for improving
throughput over the V-Link bus, we surmise, is to improve performance of Gigabit
Ethernet transfers. VIA doesn't offer an equivalent to Intel's CSA architecture,
which stems from the 875P's Memory Controller Hub (MCH). Instead, VIA's
Gigabit solution connects through the VT8237 South Bridge. The VT6120 chip
present on our reference board features Cicada Semiconductor's SimpliPHY
technology, which Cicada uses in its own 8200 series of Gigabit transceivers.
The 196-pin LBGA chip communicates over the PCI bus, which would suggest a
performance disadvantage. However, even while VIA found that Intel's 82544 Gigabit
controller transmitted at a higher throughput, its own VT6120 did better on the
receiving end. The most tangible benefit of its controller, though,
according to representatives at VIA, is effective cable reach. Gigabit
Ethernet is highly susceptible to signal noise. So, under poor conditions,
competing solutions can be reduced to as little as 10 meters of reach.
Under the same circumstance, the Velocity controller maintained 150 meters of
Another of the PT880 reference
board's strong suits is its audio implementation. Lately, we've spent a
lot of time testing small form-factor systems, including
Shuttle's SB65G2 and SN85G4 XPCs. The allure of a fully featured
chassis is undeniable. These systems offer audio, video, and networking
all in one compact package. However, subjective listening tests on both
Shuttle's SB61G2 and Biostar's iDEQ 200N have exposed quite a bit of distracting
background hiss due to noisy signals. Using a set of standard multimedia
speakers, the hiss might not be noticeable. But Sennheiser's HD600
headphones are of high enough quality to observe the problem immediately.
Simply, integrated audio needs to be implemented carefully in order to avoid
crummy sound quality. The PT880 reference board employs VIA's Envy24PT
entry-level controller and a VT1616 "Six-TRAC" codec for six-channel output.
It isn't the highest-end configuration VIA offers (that'd be the Envy24 and
VT1617 codec), but it is sufficient so that the board's audio outputs
aren't muddied by electrical noise. After suffering through several
quality recordings played back on competing integrated controllers, the
Envy24PT/VT1616 combination is refreshing.
Of course, the VT8237 South Bridge
natively supports two channels of Serial ATA connectivity, but enabling RAID 0+1
requires two more. An integrated VT6420 Serial ATA RAID controller
contributes the extra channels, and a Silicon Image PHY adds an additional pair,
for six total channels of Serial ATA. Not all manufacturers will follow
suit, though. The aforementioned MSI board, for example, comes equipped
with four channels of Serial ATA.
The reference board includes one AGP 8x slot and three PCI slots, which again, is
not representative of
a third-party configuration. MSI's PT880 sports five PCI slots,
though given the PT880's degree of integration, extra PCI slots shouldn't even
Specifications of VIA's PT880
Third-Party Boards WILL Vary
VIA PT880 North Bridge
VIA VT8237 South Bridge
VIA VT1211 Hardware Monitor ASIC
Controls 2 fans, monitors 2 fans
Features 5 analog inputs for
measuring voltage and temperature
Watch Dog Timer
Supports up to 2 Ultra ATA33/66/100/133
hard drives (chipset supports 4)
Supports ATAPI CD-ROM, LS-120 and
Compatible with SATA Specification
Supports 150 MB/sec transfers with CRC error checking
2 ports - VT8237 South Bridge
2 ports - VT6420 SATA Controller
2 ports - Silicon Image SATALink
REAR PANEL I/O
4 USB 2.0/1.1 ports
2 RJ-45 LAN port
2 DB-9 serial ports (16550 UART)
1 DB-25 parallel port
1 mini-DIN-6 PS/2 mouse port
1 mini-DIN-6 PS/2 keyboard port
6 audio jacks: line-out, line-in
and Mic-in, analog audio-out
2 connectors for 4 additional
external USB 2.0/1.1 ports
3 internal audio connector (CD-in,
1 S/PDIF in/out connector
1 connector for IrDA interface
6 Serial ATA connectors
1 IDE connectors
1 floppy connector
2 ATX power supply connectors
3 fan connectors for CPU fan,
chassis fan and power fan
1 wake on LAN connector
1 wake on Modem connector
We'd expect that most retail PT880
motherboards won't feature the exact same BIOS found on our reference board.
Even still, it's good to know that the chipset is highly flexible.
Third-party manufacturers looking to coax extra performance from the chipset
should find it an easy task. Similarly, resourceful enthusiasts can expect
plenty of options for tweaking every aspect of the platform's operation.
Front side bus frequencies are
selectable in 1MHz increment, for instance. Or, if you'd like to overclock
your AGP and PCI devices, you can choose between a number of settings. The
Ultra V-Link interconnect can even be adjusted. A whole host of memory
timing adjustments have been exposed in the DRAM Clock menu and voltages can be
set independently for CPU (1.625-1.775V), DDR (2.65-2.75), and AGP.
Check out the screenshots above for
a smattering of what the PT880, in its current form, is capable of.
How We Tested and
SiSoft's Sandra 2004