FireWire 800 Hardware - Compatibility Problems
Prior to the release of new hardware, RME carry out extensive tests not only of the hardware itself, but also of its compatibility to other hardware. When testing the Fireface 800, we found hardware errors of several manufacturers. In order to enable safe operation of the Fireface 800 for our customers, we publish the results of our tests in this Tech Info.
Reassuring: FireWire 400 (1394a-2000) has always functioned properly. We
tested PCI FireWire cards with chips from VIA, NEC and Texas
Instruments. The communication between computer, Fireface 800
and external FireWire hard drive didn't show any
The following selection has been made accidentally, depending on availability in Germany. There is no claim for completeness. We would have liked to test the FW800 PCI cards from Lindy and Trust, but they were not available at the time.
No Name 3-Port PCI-32 Bit
This card is available in Germany through various distributors and retailers. It has 3 FW800
ports and is one of the few 32 bit cards, which many users may probably prefer. But there are
actually few rational reasons for this, because 64 bit cards also work in 32 bit PC
motherboards, regarding both dimensions and electrical requirements. A statement often to be
found, that such a 64 bit card would only yield FW400 performane in a 32 bit slot, is simply
nonsense and most likely a translation error.
The other 'mistake' is harder to quantify, but it leaves us with a bad taste in the mouth.
FireWire 800, a high frequency communication protocol close to a Gigahertz, requires an
outstanding clock. TI thus specify low jitter crystals with less than 5 pico seconds of jitter.
But these are expensive. Now, what could prevent one from taking a cheap 24 MHz standard crystal
and boosting its output signal up to 98 MHz with an also cheap clock PLL IC? Correct, the jitter
aspect. But exactly this has been done here, as one can see with the crystal at the top and the
small clock PLL IC next to the left.
This card has two FW800 ports, one external and one internal FW400 port, which cannot be used
simultaneously though. It is our present 'king of misdesign'. Instead of from a voltage
regulator, the physical chip gets its supply voltage from a 1.8 V output pin of the link layer
chip - modification impossible. Also
clearly visible in the picture,
the clock section with
standard crystal and PLL IC (see also No-Name 3-port).
From the well-known German mail-order retailer Alternate, we bought a
no-name hard disk enclosure called Speedstar (order no. T3FF05). Actually a nice and
well-manufactured device. But apparently also in China, TI's unclear data sheet is not being
understood correctly, because the physical chip is being fed from
a 1.8 V regulator here,
Along these three examples, you can on one hand get an idea, what sort of
traps there are on the way to a reliable and completely compatible FireWire 800 design. Further
critical points are the layout, the high frequency design especially in the neighbourhood to the
FW sockets, ground planes and quality of the power supply. On the other hand, a web search
shows, that there are many different no-name devices available (especially outside of Germany),
of which a good deal will probably have the mistakes mentioned above.
Working HardwareBecause of the experiences described above, we recommend that all FireFace 800 users who want to use FireWire800, use only devices tested by RME. We have checked the usage of low jitter crystals, a correct supply voltage of 1.95 V and a proper function with Fireface, plus the combination of Fireface and external FW800 hard drive with the following devices.
Apple G5 Series
It actually goes without saying, but only to avoid requests: Apple's G5 computers with FW800 port are fully compatible.
The renowned manufacturer MacPower also met our expectations. The external hard drive enclosure IceCube 800 is fully compatible.
Alternate FireWire PCI
No-name ware doesn't necessarily have to bad. For example Alternate's FireWire Card 1394b 800 PCI, a 64 bit PCI card with two FW800 and one FW400 port. The card is only 54 Euros and works very well (order no. FPFV01).
Last update: 07/28/2004
Copyright © Matthias Carstens.
Copyright © 2004 RME. All rights reserved. RME is a registered trademark.