FireWire 800 questions

I have a few FireWire 800 questions:
Do all FireWire 800 connections use a 9-pin connector cable? Can the FireWire 800 with 9-pin connector also be used to power devices just like with a FireWire 400 port using a 6-pin connector? And lastly, what type of devices are generally used with a FireWire 800 port?

As far as I know yes.
You can get Firewire cables with changeable ends so that you can use the same cable 3 ways: 6 pin to 6 pin, 4 pin to 4 pin, and 4 pin to 6 pin. But never seen any that changes any of the above to 9 pin.
I have a Maxtor 300GB external HD that uses Firewire 800. It is just a bit faster and nowadays with the express cards even if you have the 15" MBP you still can use this option as opposed to FW400.
Hope this helps

Similar Messages

Firewire 800 Question

I'm just upgrading to a Mac that only has FW800, but one of my peripherals (Apogee Duet Soundcard) only has FW400. Now I've purchased the the requisite 800 t0 400 adapter, but my question is this:
Will my soundcard (or any other peripheral) be communicating with my Mac with FW800 bandwidth or 400?
Cheers,
simon

A FireWire 400 device can only operate at FW400 speed (even if plugged into a FW800 port). Further, if you connect a device that has a pass-through and you daisy-chain devices, no device in the chain can operate faster than the one that precedes it in the chain. For example, if you attach a FW400 hard disk to the computer, and then attach a FW800 disk to the FW400 disk, both disks will run at the FW400 speed. If you attach a FW800 hard disk to the computer and then plug a FW400 disk into the FW800 drive, then the FW800 drive operates at FW800 speed, and the FW400 disk at the FW400 speed.

Firewire 400/800 Questions

Hello -
I recently upgraded to a new 24" iMac and noticed that there is only one firewire 400 port (as opposed to my previous G5 which had two.) In my old configuration I had an external drive connected to one of the firewire 400 ports and all of my peripherals (DV camera, card reader, etc.) in the other port.
Now that there is only one port, and I must daisychain with the hard drive, will I run into a problem when I try to import footage from the DV camera to that external firewire drive? From what I've read only one firewire device should be used at at time and this would obviously be using two.
I am considering buying a firewire 800 drive as a potential solution and wondered if it would, in fact, be a solution. Also, would a firewire 800 port be that much faster to notice a difference? If so, I might buy one anyway.
Thank you in advance for your responses and my apologies for not really knowing much about this stuff.

I have a Core Duo, so I have two FW 400 ports. Thus I'm answering this based on theory, not experience. FW 800 is supposed to support 400 Mbps connections. So you can use the 800 port by getting a cable that has an 800 connector on one end and a 400 on the other. You can definitely use more than one FW device at the same time. However they will share the bandwidth. If they are not designed well, they might possibly interfere, but that shouldn't happen.
A typical disk drive will deliver about 35 MB/sec. A FW 400 port can handle that. However I've seen some reviews suggesting that with the most recent fast drives (particularly the big ones that bundle several physical drives into one) you may see some performance advantages to FW 800.
A lot depends upon how you use the drive. If you copy one drive to another, or use large files, you'll get very high speeds. But in normal use, the drive spends most of its time moving the heads around, and you won't see much difference between FW 400 and 800.
I would be inclined to start by getting a FW 400 to 800 adapter cable and splitting devices across the two ports as you did before.

Can I power an external ST91000640NS using FireWire 800?

Hi,
I am going to buy a new 17" MacBook Pro soon and I've been doing research on how to customize it when I get it. I want to install my own SLC SSD as the internal drive because it's cheaper and has a longer life expectancy. Because of the limited capacity of SSDs these days, I am also going to be getting an external HDD to keep all my data that would not benefit greatly from SSD speeds, as well as for backups of everything on the internal SSD.
I wanted this external HDD to meet three criteria:
1TB capacity
7200rpm speed
2.5" size, so that I can use it without needing to plug it into a power socket
There aren't many options to choose from that meet those requirements. In fact, I only found one candidate, the “Seagate Constellation.2”. It looks like a good set of specs and Seagate is a reputable hard disk maker I've read, so I'm just about ready to buy one. My only point of concern is whether it can be powered and operated solely over FireWire, or if I would have to use a power adapter.
So my question is, can the 17" MBP (Late 2011) supply enough watts/volts/amps over FireWire 800 in order to power this Seagate disk? (Sorry for rambling too much)
I have looked at the spec sheet and read up on IEEE 1394, i.e. FireWire, and I wasn't able to come up with a definitive answer, and I'm not even confident about how these electronics operate (specifically if the watt/volt/ampere requirements have to be met precisely or if they can go over or under a little, or a lot). I hope someone helps me out here.
Now here are the relevant specs, from the ST91000640NS product page:
12V start max current
0.85A
5V start max current
0.51A
Average idle power
2.95W
Average operating power
5.43W
According to Wikipedia's article on IEEE 1394, FireWire can supply a maximum of 45W and 30V.
Apple's FireWire Ports Specifications article says:
Input voltage range
8 to 33 V
Input power
0.3 W
Output voltage range
12 V to 30 V (varies by product)
Output power
minimum of 7 W per port
The disk will be put in an OWC Mercury Elite Pro Mini enclosure, by the way. (Though I don't think that matters.)

Kappy may be right — he most often is. But the Constellation is an enterprise drive designed for continuous use in servers, not for bus-powered use as an external drive. Among currently-available 1TB notebook drives, the kind that are normally used in bus-powered portable external enclosures, there are none that run at 7200 RPM, so I assume that's why you've settled on the Constellation. My concern about your plan is twofold: first, the drive is 15mm high. Will it fit in the enclosure you've selected? Ask OWC. And second, because the Constellation is normally run on AC power without any amperage ceiling that it's likely to exceed, I wonder whether during spinup or heavy usage it will occasionally draw more power than your FireWire bus can supply, causing it to be automatically powered off. I'm not conversant enough with electrical specs to be able to tell whether that's a possibility. Perhaps Kappy is.

Upgrading my intel iMac to internal SSD and running 1TB external drive from firewire 800 for mass storage while still using a second external drive for backups...my goal-speed with a SSD, to still have 1TB of room for everything i have now..possible?

I seem to kill HD's every two years...the last two i've installed were WD Caviar Black 1TB 7200rpm 3.5" drives. The speed gains over stock drives have been remarkable. I don't blame the drives for the failures, my machines are up and running 16 hours a day, every day, year round. They die from 'mileage' so to speak...i assume...there's no viral acvtivity or questionable downloads to gunk things up...just lots of work.
I have my third new drive ready to install in my intel based iMac...but i've had a thought...I want to install a SSD in my iMac for the speed gain (and recent price drops)...for standard storage i want to use this new WD Caviar Black 1TB in an external drive bay and connect via firewire 800 for storing everything except the OS and my most commonly used software...am i crazy? will the firewire 800 external drive negate the speed gained with an internal SSD??
I have four iMacs in my office, and one at home. I buy second hand and install new drives and boost memory. I'm going to do this on my 'home' machine...if it works out well i want to upgrade the other three this way...but first i need to know if i'm just dreaming, or will it really make a difference? or even possible??
Thanks!
2.66 intell core2duo
2009 iMac
8gig ram
1 gig hd
OSX ver. 10.8

The SSD gives great bootup and Application launch speed. I think it also speeds up the video rendering a bit, I do all that on the SSD and then move the finished project to the external drives. As far as the speed for the external drives they are quick enough for viewing video and the file transfer rate is good. I had initially put the SSD into an external cradle (FW800) and the system was faster than on the internal drive. I only got a 1.5GBs SATA drive, perhaps yours could benefit from the 3GBs. I know the 6GBs would be too fast and costs a lot more, even the MacPros need special hookups to make use of the 6GBs.

How to connect an external harddrive with firewire 800 to a macbook with firewire 400?

Hello,
I just got the external harddrive "Seagate FreeAgent GoFlex USB 3.0 1TB" with a Seagate FreeAgent GoFlex Upgrade Kabel FireWire 800. I have neither a USB 3.0, nor a Firewire 800 on my white macbook (2008). I already know, that it's possible to use USB 3.0 with an USB 2.0 port, but I would like to use it with the firewire to spare the USB port for other devices. My question: Is there an adapter or cable to use the Seagate Firewire 800 with my Firewire 400 port? I don't know, where and what to look for.
I'm glad for any advice.

There are many adaptors, try here

I currently have a MAC Mini, which has 1 Firewire 800 port. I have a 1TB external hard disk that runs at Firewire 400. Can I insert another external hard drive that runs at Firewire 800?

Here's the deal. Currently running SL 10.6.8 on a MAC Mini. Planning for eventual upgrade to ML. Have a 1TB external hard drive partitioned into two volumes, one volume for Time Machine and one volume for SL which I periodically update using Superduper. Thus I always have a point-in-time bootable backup on the external hard drive.
The MAC Mini supports Firewire 800. However, booting from my current external hard disk is pretty slow, since it only supports Firewire 400. I am considering buying an Iomega MiniMax which supports Firewire 800. Then, I would use the MiniMax as my bootable backup volume, and relegate the older hard drive to Time Machine.
So, question #1 is, can I daisychain the new MiniMax between the MAC Mini and my existing external hard drive? My expectation is that the new Mini Max would run using Firewire 800 and that the existing hard drive would run at Firewire 400 speed as it does today. If it doesn't (e.g., daisychaining in the Firewire 400 external disk with the MiniMax Firewire 800 external disk ends up running the whole leg at 400), my resolution will be to run the existing hard disk off an available USB port and have just the MiniMax running at Firewire 800.
Why am I going to all this trouble? That's question #2. I don't trust upgrades; they always break something. When I upgraded from 10.5.x to 10.6.x, the web directories got renamed, and all of my web apps 403'd until I figured out what happened. Plus, I have accounts for other family members, and in order to ensure their ability to use the computer during my upgrade process, I need to have the ability to fall-back quickly to a known-stable version of OSX. So what I'm trying to do is insulate myself from problems by partitioning the MiniMax into two volumes, taking a Superduper image of my current installation on the Mac Mini to MiniMax external drive volume 1, then upgrading to ML on the MAC Mini, and take a SuperDuper image of that to MiniMax external drive volume 2. Then, if the upgrade results in problems I can't resolve immediately, I can simply reimage the MAC Mini from MiniMax volume 1. BUT ...
... I've read that the ML installation creates a "service and support" partition that is different than the startup disk. I'm concerned that I won't be able to reimage the hard disk in the MAC Mini once I upgrade it to ML because of the partitioning changes it introduces on the startup disk. Theoretically, I +should+ be able to use the disk utility on my SL system to repartition the disk in the MAC Mini prior to reimaging it from my backup, but I'm considering the possibility that the new partition may be of a type that the SL disk utility cannot identify, and might therefore be unable to delete or even detect. So I'm hoping someone else has been down this road and can advise me. Even at Firewire 800 speeds, booting from an external disk is still going to be slow, so I want to be able to restore my SL image to the MAC Mini hard disk.
A little background on me. I work for a major disaster recovery provider. I used to have a Mac PRO G5, which I got used, and the first thing I did with it was install a second hard disk, SuperDupe an image from the first disk to the second, and made sure I could boot from the second. THEN I started using and customizing the MAC. I really feel vulnerable with the MAC Mini, since it only has the single internal hard drive - sort of like going out in public dressed only in a long T-shirt. So my whole thing is, I ABSOLUTELY MUST BE ABLE TO PUT THINGS BACK THE WAY THEY WERE before I do the migration to ML.
Obsessive-cumpulsive? Yep. Anal? You got it. That's why I'm in the DR business.

You may have overloaded the port, following the instructions below it should reset:
+1. Shut down the computer.+
+2. Disconnect all devices and all other cables, except the keyboard and mouse cable(s).+
+3. Disconnect the computer from the power outlet and wait for 3 to 5 minutes.+
+4. Plug the computer back in and turn it on.+
+5. Reconnect the device(s) (one at a time if there is more than one) and test. Test with each port if you have more than one.+
http://support.apple.com/kb/HT1317?viewlocale=en_US

Can I Boot my PB from a Firewire 800 External HD?

I'm a going to buy a portable external HD for my mirror (clone) back-up drive.
I can buy either a Firewire 400 ("Combo case") or 800 ("Triple case") HD. My inclination is to buy the Firewire 800 ("Triple case") drive as it will be more useful in the future.
Will I be able to Boot my Firewire 400 PB from the Firewire 800 External HD as long as I have the right adapter cable? Or do I have to get a Firewire 400 instead?
The drives I have in mind come from OWC and have a port for an external power supply if it's needed.*
* http://eshop.macsales.com/shop/firewire/on-the-go, to see where I'm going with this.

Moot Question.... No further need to answer!!!

Can't boot from clone on external firewire 800 drive

Hello,
I have a 24" mid-2007 iMac 7,1 running Snow Leopard. I recently changed my set up to put a clean install of OS X 10.9.1 on a partition of an external SSD. I also moved the 10.6.8 start up system to a partition on the SSD. My internal iMac hard drive now has no system folder, only my data files. I have additional firewire drives for Time Machine, other data and media drives. Finally, I just bought a pair of 3TB drives that I partitioned into enough partitions to be able to clone both operating systems and all my data files for a rotating pair of offsite backups. All moving/cloning of drives was done with version 3.5.4 (Mavericks-compatible) of Carbon Copy Cloner.
I can boot from my external SSD (either Mavericks or Snow Leopard) fine and all external drives mount correctly in either case. After cloning all the partitions onto the backup drives, I tried to test the clones but I am not able to start up using either the Mavericks or the Snow Leopard clones when the backup external drive is connected via firewire 800. This is true whether I select the clone volumes in the Startup Disk preferences pane or hold down the option key during start up (note that the external drive with the clone partitions does not appear in the list of disk choices with the option key method). I get the "question mark in the folder" sign that the start up system is not being found.
I have changed the order in which the external drives are connected (normally the SSD is first in the chain), including trying when only the backup drive is connected directly to the iMac. I get the same result no matter what.
Curiously, the Mavericks and Snow Leopard boot clones start up via firewire 800 when the external backup drive is connected to my wife's 2009 13" Macbook Pro, indicating that the clones and the enclosure (an OWC Mercury Elite Pro quad interface, newer version with USB3) both support booting. Furthermore, if I connect the backup drive to my iMac using USB, the boot clones both work to start up the iMac.
This all points to an issue with the firewire bus failing to recognize the boot clones somehow during my iMac's start up process. I am rather puzzled about how to fix this.
I can get by booting via USB in an emergency but because my system is old, this is of course USB2 so its slow. If I had to use the clones to recover I'd rather be able to operate and restore at FW800 speeds.
If anyone has any ideas what might be going on, I'd appreciate hearing them.
Thanks in advance.
Greg

Did you ever get this resolved, Greg?

Time Machine won't mount Firewire 800 drive after restart / Finder crashes

I've been having problems with Finder crashes. I first suspected Spotlight might be the problem because sometimes when I started typing a search, it would display the first 3 characters and then lock up. I could force quit the Finder, but it wouldn't relaunch and required the computer to be shutdown and restarted with the power button. Once restarted, I had no keyboard and no mouse click (the mouse would move across the screen but I could not click on anything). After waiting several minutes (3-5) the mouse and keyboard worked properly.
After some research suggested the Spotlight index might be corrupt, I forced Spotlight to rebuild the index (add the drive to the exclude list under "Privacy" and then remove it from the list) and then repaired disk permissions. After that Spotlight was noticeably snappier and I thought my Finder crashes had been solved until........
Part 2: I have been using Time Machine (connected to a Fantom GreenDrive via Firewire 800) for several months now and ever since the beginning, I have noticed that the drive will NOT mount after a restart. I must turn the drive off and back on again to get it to mount. After that Time Machine picks it up and seems to work fine.....well, that is until this Finder crashing thing started several weeks ago. Anyway, I inadvertently set up an experiment last weekend when I installed some software update and forgot to remount the Time Machine drive after the restart. That was last Sunday night. The computer did not crash all week long. I thought my Spotlight fix had finally solved my problems, but now it seems I was wrong. This morning (Saturday, six days later), I noticed my Time Machine drive was not mounted. I mounted it, told Time Machine to "Back Up Now" and went away for a few hours. When I came back the Finder was locked up.
So guess my question is this: Are there any know problems with using Firewire 800 with Time Machine? and What can I do to fix this? In the meantime I'm trying another experiment - I've disconnect the Firewire 800 connection and replaced it with USB.

shaneeudy wrote:
So guess my question is this: Are there any know problems with using Firewire 800 with Time Machine?
Hi, and welcome to the forums.
Not in general. Some drives don't always wake or "spin up" fast enough; often that's seen when the system wakes from sleep, though, not so much after a system Restart. Many Western Digitals do that; I don't recall seeing any posts here about yours, but you might want to search the forums for Fantom
In the meantime I'm trying another experiment - I've disconnect the Firewire 800 connection and replaced it with USB.
Good plan - that may provide a clue.
Also, check with the maker -- there may be a firmware or driver update.
And try verifying your internal HD, and repairing your backups, per #A5 of Time Machine - Troubleshooting (or use the link in *User Tips* at the top of this forum). Either might cause that.

Firewire 800 speed weirdness

I recently purchased a four bay RAID array to replace the multitude of external drives that I've collected over the years. I installed four 1TB drives in a RAID 5 configuration to make up a 3TB array. The RAID model is the DM4 from Sabio (Sabio DAS DM4).
I connected it to my iMac via Firewire 800 (it has 2x FW800 ports, 1x FW400, 1x USB 2.0, 1x eSATA), and after hours of copying from the external USB drives I finally got everything migrated over to the new monster drive. However, I am seeing some weirdness in transfer speeds.
My iMac specs are as follows:
Model Name: iMac
Model Identifier: iMac7,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.8 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 4 GB
Bus Speed: 800 MHz
Boot ROM Version: IM71.007A.B03
SMC Version (system): 1.21f4
I was testing copy speeds to the array by using the cp command in the terminal and watching the disk activity in iStat Menus (but you can get the same information out of Activity Monitor on the Disk Activity tab). Using cp, I was only able to push about 45MiB/s, which I found strange since this is near the maximum of FW400 (50MiB/s).
The truly weird thing, though, was using the same file, copying to the array in the Finder pushed the transfer up to 65MiB/s. The main question I have is why would that be? I've tried alternates on the command line as well, such as rsync but nothing moves as fast as the finder.
Now I get that writing to the array is going to be slower considering that I'm writing parity to all the drives, but I don't get the speed difference between the command line tools and the GUI Finder. Maybe it's a caching issue?
I'm also seeing a hit between the command line and the Finder with reads from the array. Unsurprisingly the reads are better than the writes, since I'm pulling from four drives. With the Finder, I'm able to pull at an average rate of 75MiB/s. The command line I read around 63MiB/s to 66MiB/s.
All these tests are the same file. The drive in the iMac is actually brand new (1TB Seagate), and it has barely anything on it so it's not some type of fragmentation issue. The only external drive on the iMac is this Sabio array.
So, does anyone have any ideas why I'm seeing such a speed difference between the command line and the GUI? Also, is there a way to work around this slow down on the command line? Hopefully someone knows more than I've found thus far.
Thanks for your time,
Adam.

You're right, I could use the Finder to do all my copies, but I typically don't use my systems at that level. I know that sounds weird, but I'm a Linux admin and systems engineer by trade and I live in the command-line/terminal all day long. I am a lot faster at manipulating the system via the command-line than I am with point and click. There are a lot of times that I just quit the Finder outright so I don't have to look at my Desktop icons (though I have the desktop turned off right now so I don't see any icons at all).
I generally use my iMac as a media center, where it serves media to my PS3 and what not. I also use it for some development work. My wife will use the machine for graphic design when she is working form home thus she's in the Adobe Creative Suite a lot of the time. With that said, the machine is mutli-user, and I typically use command-line programs to ensure that what I copy is copied correctly via rsync, or the cp -Rp commands.
Now, my observations were not really a concern, but more of a why-on-earth-is-this-happening type of thing. In the past, it used to be a lot faster and more efficient CPU wise to copy via the command-line than it was in the Finder. Now with Snow Leopard they seem to have gone the other way around. To me, it just seems that the command-line equivalent, which doesn't have any glitz or glamour at all, should be natively faster than the Finder, which has progress bars, drag-and-drop, etc.
So yeah, I can use the Finder, but it's not what I use normally.

What is FireWire and what FireWire adapter do I need to use FireWire 800 for my portable external hard drive ?

Hi guys, I'm new to Mac. I have a MacBook Pro 13" (late 2011) with Lion OS and Parallels 7 (Windows 7). My understanding is that there is FireWire connection / extension built in to the MacBook Pro already. I also have a Seagate FreeAgent GoFlex portable external hard drive 750GB USB2.0 and 3.0 (that can be used for PC and Mac). It states that the portable external harddrive is FireWire 800 compatible. The questions are (1) how does FireWire works ? (2) how do I use or activate FireWire 800 ? (3) is there any setup / setting changes I need to on my MacBook Pro ? (4) what FireWire adapter do I need to purchase to connect my portable external harddrive to my MacBook Pro ? Is it expensive ?
I read a few articles online but they are too technical for me. They mentioned something about FireWire adapter with 6 pins or 9 pins. Not sure what that means. I'm totally confused. So any help, advise or guidance will be much appreciated. In Layman's term would be better. Thanks.
How about Thunderbolt ? Is it compatible with the above external portable hard drive mentioned ? Do I need a Thunderbolt adapter for it ? How do I activate or use Thunderbolt ?

Thanks, Clinton and Alberto.
The below link is the Seagate FreeAgent GoFlex portable external hard drive (product code STAA750302) that I have. It states that it features USB 2.0 or 3.0 plug–and–play connectivity and easily upgradeable to USB 3.0, FireWire 800 or eSATA. It only comes with a 18-inch USB 3.0 / 2.0 backward compatible cable.
http://www.seagate.com/au/en/external-hard-drives/portable-hard-drives/standard/ goflex/
Based on the above, my understanding is that I need to buy a FireWire 800 adapter to connect to the portable external hard drive so that I can use FireWire 800 with my MacBook Pro. Is this correct ? Do I need to get a separate cable as well or can I just use the 18-inch USB 3.0 / 2.0 backward compatible cable that was provided in the box ? If so, what sort of FireWire 800 cable do I need to get ? 9 pin to 9 pin ? 6 pin to 9 pin ? Or 4 pin to 9 pin ?
https://www.lindy.com.au/online/arrshop.exe?anonymous=true&cat=b1

Can I use my firewire 800 wd hd in my windows boot camp?

I have a my passport studio 1tb hd with usb and firewire 800, i just installed windows 7 via bootcamp on my computer. I partitioned a portion of it to exFat which I plan on converting to NTFS or something. Can I use it with the firewire cable any way? I don't have the usb with me at the moment.

I removed the exfat partition because windows didn't recognize it. I left about 200 gb of free space though. I looked in computer management, under disk management and windows shows my ext hd as being unallocated, even though it is hfs+ and contains about a gigabyte of info. My question is: if I try to make a partition using windows, will it erase the information on my hfs+ portion?

Firewire 800 to VGA?

Hey guys and gals. I've run into an issue. In September, I bought the 21.5" iMac (Mid 2011) which of course has Thunderbolt. I intend on getting a 21.5" Dell Display to accompany my awesome new iMac. (insane machine. renders 1080p like a beast) I've decided to get the Dell display since it has HDMI, which I will use with an Xbox 360.
This is all relevant, since I also want to purchase Blackmagic Design's Thunderbolt HDMI Capture Card, the Intensity Extreme to record gameplay. As you may know, the 21.5" iMac only has one Thunderbolt port. For the display, I'd need to use it for Mini-DV to VGA, and for the Intensity Extreme, I'd need to use it since it uses Thunderbolt.
So, is it possible to use Firewire 800 for the display? Is there a Firewire 800 to VGA adapter on the market? Or alternatively, Is there a Thunderbolt hub or any plan to make one?
Thanks guys.
To answer any questions:
1. Blackmagic doesn't make a USB or Firewire capture card, only PCI Express and USB 3.0, neither of which the iMac support.
2. I don't want to settle for a different capture card like, say, the Hauppague HD PVR. Sure the quality is nice, but Component cables are very messy and the Dell display that I'd like is HDMI. Very handy.

So, is it possible to use Firewire 800 for the display? Is there a Firewire 800 to VGA adapter on the market? Or alternatively, Is there a Thunderbolt hub or any plan to make one?
Nope this will not work, there is no such adapter. Regarding a hub I was able to find this article:
http://michael.olivero.com/post/2011/09/16/Thunderbolt-Hub-Has-Arrived!.aspx
However I don't know if it has been released yet, I'd recommend contacting Belking to inquire.
Had you gotten a 27" iMac they have two Thunderbolt ports, you could easily connect one to use a minidisplay port adapter to the Dell display and the other for another Thunderbolt device.

Daisy-chain Firewire 800 versus USB

Hi. I have an external drive (drive A) connected to my MPB via Firewire 800. I have my iTunes media library on this drive (movies, TV shows, music etc). When I watch a movie on my Apple TV, the content is being streamed from this drive via my MBP to the Apple TV. This works fine.
I also have a second external drive (drive B) that I use only as a back-up for drive A. I use Carbon Copy Cloner to back up drive A onto drive B. I can connect drive B in one of two ways: Option #1 is to connect drive B directly to my MBP via USB (USD 2.0). This is how I currently have it connected. Option #2 is to connect drive B to drive A via a Firewire 800 cable, daisy-chaining the two drives.
Two questions:
1. Which option will give me better performance when backing up drive A to drive B?
2. If I am watching a movie on Apple TV (streaming from drive A) at the same time that I am backing up drive A to drive B, will option #2 affect streaming of the movie?
Thank you

Have you Shut down your Mac and disconnected your firewire cable from both ends and let it sit about ten minutes then reconnect and try. Also, it is important to disconnect the AC power to your Mac, this helps to reset the FireWire port(s).
Have you checked to see if Disk Utility sees it/ can mount it?
Do you have TechTool Pro or DiskWarrior, both of which you could use to try to mount it.
It is also possible that you have a bad cable or a bad port, do other FW devices work?
-mj

FireWire 800 questions

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