Firewire: Advantage to having onboard SiS648 mobo vs. PCI card?

[SnakeEyes45]

I'm considering a new motherboard and I need FireWire capability. Plan to use for video editing, though not professional stuff--mostly recreational/amateur family and wedding editing. Based on some of the problems I've seen reported thus far with the Asus P4S8X board, which has built-in FireWire, I'm shying away from the board and competitors, and will instead likely go with an 845G-base board, like the Abit BG7. I can add a PCI card with FireWire for about $25 to a BG7 and it will still cost less than the P4S8x. I'm thinking of stability here over the other added features of the new P4S8X.

My question: Given that FireWire supports bandwidths of 100,200,and 400 Mbps, isn't that an issue when considering a PCI-based add-on card. Won't all of that data go through the PCI bus at 33Mbps second? And won't that introduce it's own bottleneck? I'm assuming that this is not a problem with SiS648 boards, as the controller is built into the chipset and because of the Mutiol link between bridges on the motherboard.

Am I right in assuming there is a performance issue here or am I missing something? What's the theory in play here and what's the real, practical impact.

Advice?

 

[Peter]

Don't confuse Mbits/s with MBytes/s. PCI is 133 MB/s while FireWire is up to 800 Mb/s.

But yes, PCI FireWire controllers are major system bandwidth hogs while SiS's chipset integrated one is not. Big plus. Same is true for USB 2.0 btw.

 

[MetroRider]

But yes, PCI FireWire controllers are major system bandwidth hogs while SiS's chipset integrated one is not. Big plus. Same is true for USB 2.0 btw.

Peter,

is that really so? is there any site that has done benchmarks between onboard Firewire and pci-based firewire cards? this seems to be an interesting topic, especially with many firewire devices such as hard-drives and camera links which can use all the speed they get.

thanks,
David

 

[senior guy]

I agree with Peter that it would be preferable to get a SiS648 board that implemented the chipset's built-in 1394, but for some strange reason, no SiS648 board released so far (other than perhaps the Asus P4S8X) has implemented this feature! - and unfortunately, the P4S8X is receiving very poor 'grades'!

 

[IntelConvert]

Originally posted by: Peter
... But yes, PCI FireWire controllers are major system bandwidth hogs while SiS's chipset integrated one is not. Big plus. Same is true for USB 2.0 btw.

Peter: I sure would like to understand the basis of this remark... I just don't see why that should be.

 

[Vette73]

If you are not looking for a MAJOR overclock then look.....

Newegg.com Board with Firewire

It has on-board USB2.0, fire wire, 6ch sound, and a host of other items for $125 shipped.

Might be what you want and not break the Bank?

 

[rubik]

Does anyone have a definitive answer to this question? (or even a theory.. )

I am debating whether to go ahead and get the Gigabyte offering of the SiS 648 and use a PCI Firewire card or wait for another manufacturer to release a solid 648 board with onboard Firewire. The Asus board sounds too flaky.

 

[Peter]

Originally posted by: IntelConvert

Originally posted by: Peter
... But yes, PCI FireWire controllers are major system bandwidth hogs while SiS's chipset integrated one is not. Big plus. Same is true for USB 2.0 btw.

Peter: I sure would like to understand the basis of this remark... I just don't see why that should be.

This is because the SiS chipset interconnects its components with a 1 GByte/s proprietary bus, while the total bandwidth for everything PCI is a mere 133 MByte/s. Furthermore, the path from system core to chipset south bridge is just one step, while PCI is one hop further down, past the south bridge.

regards, Peter

 

[Insane3D]

Basically to add to what Peter said, when the Southbridge has native support for Firewire, the ports are mapped to the Northbridge/Southbridge high speed interconnect, allowing for much more bandwith than the PCI bus allows, and it also doesn't take away any bandwith from other PCI peripherals, as a add on PCI card or integrated controller mapped to the PCI bus would.

This is also an issue with S-ATA. No chipset out currently has native S-ATA support, and the boards that have it now are offering it through a add-on controller on the PCI bus...usually a Promise chip. The max bandwith that S-ATA can achieve is ~150MB/s while the PCI bus can only support 133MB/s. So, basically, S-ATA can never achieve it's maximum throughput (not that it would anyway with current drives) on the PCI bus.

 

[senior guy]

Yes BUT let's see you guys name the boards that have implemented the SiS963's integrated IEEE1394!!!

 

[Peter]

http://www.ecs.com.tw/products/l4s8a2.htm
http://www.ecs.com.tw/products/l4s8a.htm
http://www.ecs.com.tw/products/l7som_3x.htm

 

[senior guy]

Originally posted by: Peter
http://www.ecs.com.tw/products/l4s8a2.htm
http://www.ecs.com.tw/products/l4s8a.htm
http://www.ecs.com.tw/products/l7som_3x.htm

Well Peter, I have to admit that the ECS L4S8A(2) is the only board I've seen that actually uses the SiS963's host 1394 controller. The problem is that although ECS may be the largest motherboard manufacturer, there's a "cheaply built" stigma associated with their boards and (perhaps because of that stigma) try to find any US websites that has reviewed the L4S8A2...

 

[Peter]

Yes, the online reviewers like the more expensive boards 'cause they offer more toys to play with. ECS boards are straightforward and extremely boring

 

[senior guy]

Originally posted by: Peter
Yes, the online reviewers like the more expensive boards 'cause they offer more toys to play with. ECS boards are straightforward and extremely boring

Peter~ Sorry, but I don't buy that reasoning. To prove my point, one very recent example of a SiS648 board, the Gigabyte GA-8SG667 (hardly a board with 'lots of toys') has been the subject of several reviews here at Anandtech as well as other US hardware sites.

IMHO, the real reason is the perception (whether true or not) that ECS boards are poorly engineered and cheaply built...

 

[Peter]

Yes sure, it's only $55, it just CAN'T be for real. I know that kind of reasoning too well Yet still, ECS don't have such great success for nothing - plus it's not like Abit and Shuttle outsource mainboard production (and in case of Shuttle even design) to ECS because they like to end up with total crap ...