#Motherboards for PVR
06-Oct-95 04:12:33
Sb: #Motherboards for PVR
Fm: Doug Hembruff 102711,1127
To: George Plhak 71530,3412
George Plhak
The following are some tips I've picked up when trying to decide which
motherboard to buy for my Perception Video Recorder. If you or anyone else can
correct any misinformation or add tips to the list, that would be helpful for
anyone considering this purchase decision.
1/ Thank you for the tip of using Colorgraphic graphics boards on the EISA or
ISA slots. That sure sounds like another way to free up PCI slots without a
compromise. However, I had already made my purchase of the Matrox Millennium
boards based on reputation, compatibility, virtual screen ability, reasonable
price and ability to hold up to 8 meg of WRAM if desired to give 24 bit at 1200
X 1600.
2/ The Intel design does not allow for more than 4 PCI slots at this time. Any
add on's to increase the number of PCI slots will decrease the performance & is
not recommended by Intel. Intel is working on a dual bridge board to add 4
more PCI slots.
3/ Buy the Microsoft Windows NT software first & check the "Hardware
Compatibility List" booklet that comes with it before you buy hardware such as
a CDROM.
4/ At the moment, I'm told dual Pentium systems only run as high as 120 MHz and
work with the Intel Neptune chip set. Motherboards that use the Neptune chip
set can't run EDO ram, only regular ram. Brand examples of these motherboards
would be American Megatrends Titan II or the ASUS.
5/ When purchasing the second Pentium for a dual board, it must be a perfect
match with the numbers on the first chip. If you buy the second chip 6 months
from now when software is available to take advantage of it, finding a match
could be a problem. If you buy both Pentiums now, and software is not
developed for the second chip, you've wasted several hundred dollars on a
second Pentium.
6/ Single Pentium systems can work up to 133 MHz & will soon run even faster.
They use the Intel Triton chip sets such as is found on the Apollo motherboard.
The Triton chip sets run about 10 – 15% faster & they can use EDO ram which
runs 5 – 8% faster for a total of roughly 20 – 22% faster than a Neptune chip
set.
7/ Check to see if the BIOS has flash rom that can be updated from software. I
heard of an situation using Dell computers where it wouldn't even boot at all
when NT was installed because the bios information was incompatible. The
solution was to flash the bios with updated drivers that did work. It's scary
to think that nobody bothered to even try it with NT before thousands were sold
to the business community.
8/ I've heard that ASUS motherboards have a PCI bridge problem with the Matrox
Millennium graphics card but I don't know if it's true.
9/ Motherboard should have 512K cache not 256K.
10/ Seagate Barracuda 4.3 Gig hard drives seem to be the only drive that is
working on nonlinear systems with minimum problems. I have been told that sure
suppliers will modify then to run better on A/V applications but I don't know
what this involves or whether it is recommended. The IBM 4.3 Gig Ultrastar did
not pass the DPS approval test for running with the Perception.
11/ I'm getting a lot of advice to do everything possible to keep large
capacity drives as cool as possible so they don't fry themselves.
Some drives can be bought as an external with their own individual box, fan &
power supply. This is not a bad option but I wonder about the integrity of the
connections when looping external SCSI cables from drive to drive. Another
solution is to put them all in a big drive box with only one external SCSI
cable connecting the box with the computer. Once inside, the drives are
connected with the more reliable (potentially) 50 pin SCSI ribbon cable.
Whether you put the video drives in the computer or a separate tower, it's
probably a good idea to put them in every other drive bay and add an extra
cooling fan. I keep hearing that proper termination is a concern for SCSI
drives & that an active terminator is a good idea on the last drive.
12/ Despite the recommendations to get the video hard drives out of the
computer and into another box, the DPS Perception card doesn't have a 50 pin
external SCSI connector so you will need to buy a 50 pin ribbon connector to 50
pin miniature external SCSI connector on a bracket & mount it on the back of
the computer.
13/ The mouse will take up one of the two serial ports unless you use a bus
mouse card which I am told is not a good idea. Some motherboards have a
separate connection for PS2 mouse support using interrupt IRQ 12. In addition
to the mouse, serial ports are also needed for modem, RS232 to RS422 machine
control, UPS interface and other things. Any way you look at it you're going
to have to put a switcher box on one of the serial ports to accommodate
everything. It may not be a good idea to use an internal modem since it can't
be switched to another device when the serial port is needed.
14/ The Perception board usually would be on the PCI slot that is closest to
the ISA slots so the daughterboard can overhang a spare ISA slot.
Unfortunately this end PCI slot on many motherboards is not full length because
the CPU & fan get in the way. You need to choose a motherboard where this slot
is full length unless you can afford to waste a PCI slot. You can use a riser
board to allow the Perception board to clear the CPU & fan but there is
potential for problems & the Perception board may not line up with the openings
in the case.
15/ If you're going to have a SCSI controller for the systems drive & CDROM,
you would normally use a PCI slot for the SCSI controller. If you want to free
up a PCI slot, you can buy a motherboard with SCSI built on it or buy a mother
board with EISA slots rather than ISA slots & use an EISA SCSI controller
board. EISA is 32 bit & can handle SCSI, ISA is only 16 bits.
16/ It is probably not a good idea to install games on the hard drive of this
computer least some of the assigned files conflict with the main applications
this workstation was built for.
17/ It's important to purchase a computer that you can change the IRQ level
priority setting in the bios.
18/ I have E-mailed in:sync to see if the Horita TRC-50PC linear time code
generator/reader/RS232 out will work with their software for importation of
time code. If it works, it would provide a way to import time code without an
RS422 VCR.
19/ If you have an RS422 VCR with time code, you can purchase ($68. us) an
RS422 to RS232 adapter cable that should work with the batch capture feature of
in:sync Speed Razor Mach 3. Call Addenda Electronics in California at (408)
372-6192.
20/ Nobody yet has been able to tell me how much memory is too much when using
the Perception/Speed Razor on Windows NT. Sounds like 32 meg will do but 48 or
64 would be better.
Regards; Doug Hembruff Impact Televideo Productions London, Ontario, Canada