PCMCIA firewire card vs Daisy chaining devices

I have two external devices - a 7200 rpm hard drive and a 16X DVD burner. I will be using both at the same time. Since only firewire is giving me the transfer rates I need, I am thinking about the following options:

  1. Buy a PCMCIA firewire card with two ports. My external hard drive will be connected to one port and external CD burner will be connected to the second.

  2. Daisy chain the two devices to one firewire (onboard) port.

Any suggestions on which approach is better? Will the bus be ‘shared’ like in USB 2.0 in either cases?

Hi :slight_smile:
In theory firewire should be the better option daisychaining compared to USB.
I have in the past run 3 devices this way without any noticable drop in performance.
Generally cards suffer a performance drop. This varies but I personally would use this option last.
With USB you could if you’re not already using one, try a externally powered hub to offset any performance slump.

Hey!

Ok then daisy chaining seems to be the way to go then. All I need to do is think about buying a good firewire enclosure now :stuck_out_tongue:

I am using an externally powered hub, 7 devices connected but without any performace gains :eek:

Hi :slight_smile:
Powered hubs don’t make any gains, but prevent losses. But I guess that’s what your saying. Is it possible to use the DVDRW on it’s own connected direct to computer’s usb port. If so what happens then.
Firewire just SCSI should in theory allow upto 18 devices daisychained with out any significant loss in performance.
By the way in my previous post I mention the performance with cards. It is possible to find one that actually boosts performance. I get this with an eternal ata card. So depending on cost it might be an option for you & usb, although firewire should give more for less if you see what I mean.

Thanks :slight_smile:

I did try conencting the DVDRW directly to the (onboard) USB, bypassing the hub. Still the same (bad) performance as connecting thru the hub. This maybe because theres a hard drive connected to the other USB (onboard) port and that would share the bandwidth.

What do you guys mean by daisy chain. A daisy chain, as I understand it, a true daisy chain, as in SCSI HDD setup’s is one device plugs into the next, into the next, an dso on untill finally the last plugs into the PC.

AFAIK, unless some new board or invention came out, you can not daisy chain USB or Firewire.

Anyhow, going forward, FireWire is probably a better option, because USB is a shared bus and having two devices plugged in will take away half the resource from each… this also proves problematic sometimes when you have many USB devices, because to some degree they all slow down.

I would def go with firewire on this one, I won’t even mention the stability factor. :wink:

That’s exactly what I mean - conenct one firewire device to the other, the next into the next and the last one to the firewire port on the computer.

Agreed, but does a firewire PCMICIA card have the same advantages as having two onboard firewire ports?

My external USB/Firewire box has 2 Firewire ports on it to daisy chain :wink: > http://www.dealsonic.com/stpmblsmbaco1.html

firewire - all the way

firewire;

  • uses much less cpu resources
  • doesn’t have shard bandwidth limitation
  • closely resembles scsi

usb;

  • never was designed for use with mobile platform
  • hogs the cpu
  • has serious transaction translator flaws - almost every consumer grade usb hubs do too

…but does a firewire PCMICIA card have the same advantages as having two onboard firewire ports?

i’d have to say …no

  • i “think” iirc - the pcmcia interface really uses usb circuitry within it - though it is a ‘system’ bus type - will create yet another layer, more wires, more circuitry, etc.etc

read more about usb and it’s flaws HERE

Which means that with my laptop, the best bet would be to daisy chain the DVD writer and hard drive - which would still give 400mbps to both the devices…And fortunately my new Plumax enclosure has two firewire ports for daisy chaining :smiley:

One more question…which is the best firewire enclosure for a hard drive. I already have this one: http://www.dealsonic.com/plpmblcousb22.html which works great for my BenQ 1640. The next one of course would be for my hard drive (which is currently in USB 2). Anything better than this for around the same price?

3x as much;
http://www.granitedigital.com/catalog/pg23_firewireidecasekits.htm

but hey - if that $30 job performs well - you have your answer already…the main diff may be the chipset/s they use - iirc - these firevue’s use T1 (texas instruments), although that may be just for the PCI cards.

there’s a really big HDD and DVD Case Enclosure thread around here somewhere

Thanks for your responses!

Found on link on Seagate’s site which says “For best performance on 1394 don’t daisy chain devices. If you daisy chain devices you are sharing the bandwidth available on that port.”

http://www.seagate.com/support/ts/external/usb_perf/01_usb_limits.html

Hi :slight_smile:
You’ll note that they only support 1394a at present. If support for 1394b was available, I think their response to daisychaining would be more favourable.

ExpertTech > I would go with one that is 5.25 that way you can put an ODD in it if needed down the road. I haven’t tried to daisy chain with my box as i only have one.
Go Cards

i don’t recall saying to ‘daisy-chain’ the devices

– it doesn’t share the bandwidth per port…iow - each port should have it’s own controller
– whereas Mobo USB ports have 1 controller per set of 4 ports - the better ones, use 1 per 2 ports (depending on the mobo’s header).
– the better pci cards should have this

i don’t know of any interface type that actually increases in bandwidth as you add more devices. iirc - one of scsi’s benefits/ability from daisy-chaining drives is in the interface’s ability to use ncq - to “organize” and ‘sort’ the commands, not as FIFO (first in first out) - somewhat like making a ‘grocery-list’ and then shopping by aisle, rather than jumping all around the store, item by item.

honestly - i haven’t really been keeping up on firewire technology, but your CPU will love you much more if you use that over usb…and some stuff above is from older memory that i haven’t looked up again recently.

also - research some newer enclosures and chipsets - as i recall, there was an issue with a top-end chipmaker and the firewire800 drives/enclosures - but that’s since been worked out (iirc - it wasn’t T1 either)