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Thunderbolt NOT 10gb/s

B

Babyboi

macrumors regular
Original poster
Mar 16, 2008
123
8
Hello, world.

Can anyone tell me why thunderbolt isn't transferring at 10gb/s as advertised?

I did a file transfer from one macbook pro to another using Target Disk Mode.
file transfer size: 18.75 GB
time: 6m:17s
first mbp is SSD crucial m4
2nd mbp is standard 5400 rpm HDD


what are the conditions that will allow 10gb/s using thunderbolt? is something wrong with my setup? Also is there another way to transfer using thunderbolt without using target disk mode? (besides airdrop as well)
 
What is the max speed of your SSD? :confused:

By the way, 10Gbs is the theoretical limit the cable can support, not the advertised transfer speed. Transfer speed relies on many factors.
 
I did a file transfer from one macbook pro to another using Target Disk Mode.
file transfer size: 18.75 GB
time: 6m:17s
first mbp is SSD crucial m4
2nd mbp is standard 5400 rpm HDD
Click to expand...

Wait, you were reading from the SSD and writing to the HDD? If that's the case the bottleneck will be the 5400 RPM drive, you wont get >100mbit write on that drive.
 
The limiting factor here is the 5400RPM hard drive. As the above poster mentioned, 10GB is the theoretical bandwidth, no device actually can do that.
 
NT1440 said:
What is the max speed of your SSD? :confused:

By the way, 10Gbs is the theoretical limit the cable can support, not the advertised transfer speed. Transfer speed relies on many factors.
Click to expand...

Crucial M4:
Sustained Sequential Read
up to 500MB/s

Sustained Sequential Write
up to 175MB/s
 
Babyboi said:
Hello, world.

Can anyone tell me why thunderbolt isn't transferring at 10gb/s as advertised?

I did a file transfer from one macbook pro to another using Target Disk Mode.
file transfer size: 18.75 GB
time: 6m:17s
first mbp is SSD crucial m4
2nd mbp is standard 5400 rpm HDD


what are the conditions that will allow 10gb/s using thunderbolt? is something wrong with my setup? Also is there another way to transfer using thunderbolt without using target disk mode? (besides airdrop as well)
Click to expand...
Thunderbolt has fail written all over it. I returned a seagate TB adapter and Apple's overpriced cable because it couldn't keep pace with USB 3.0.
 
1. it is 10 gigabits per second, so that translates to 1.25 gigabytes per second.
2. the bottleneck is the drives, not the thunderbolt. A 5400 rpm hd can do maybe 80 MB/s read speed tops. An ssd can do 500 MB/s read speed tops (SATA III).
 
Babyboi said:
Crucial M4:
Sustained Sequential Read
up to 500MB/s

Sustained Sequential Write
up to 175MB/s
Click to expand...

Either one of those would flood the 5400RPM drive. The fastest 7200RPM 3.5" drives are around 140MB/s sequential write. Most of the time you won't get that high. The 5400RPM drive is below 100MB/s read or write.
 
Yeah...dude. Your SSD can only top out at 550MB/S if you get lucky.

10Gbps is about 1.2 Gigabite per second transfer rate. Good luck find a client SSD that will offer that. You will need something like Pegasus to find the full power.

I don't even want to talk about your HDD. Get that crap out of here. Geo Metros don't get to ride with M3s
 
Freyqq said:
1. it is 10 gigabits per second, so that translates to 1.25 gigabytes per second.
2. the bottleneck is the drives, not the thunderbolt. A 5400 rpm hd can do maybe 80 MB/s read speed tops. An ssd can do 500 MB/s read speed tops (SATA III).
Click to expand...
My new Seageate Backup Plus 2.5 reads and writes well over 100MB/s. This of course using USB 3.0.
 
Last edited:
Babyboi said:
Hello, world.

Can anyone tell me why thunderbolt isn't transferring at 10gb/s as advertised?

I did a file transfer from one macbook pro to another using Target Disk Mode.
file transfer size: 18.75 GB
time: 6m:17s
first mbp is SSD crucial m4
2nd mbp is standard 5400 rpm HDD


what are the conditions that will allow 10gb/s using thunderbolt? is something wrong with my setup? Also is there another way to transfer using thunderbolt without using target disk mode? (besides airdrop as well)
Click to expand...

Thunderbolt is 10gb/s....your drive is not.
 
If you're looking to test that bandwidth out for it's maximum - it will be an expensive test. RAM drive, or fiber channel / sequenced drive array is about your best bet for saturating the thunderbolt interface.

I believe the 10gb connection speed is more about reducing latency, so that multiple devices can access the bus without bottlenecking. (running a display AND a camera AND an external drive or port replicators).

You also have to consider not only the devices limitations, but error checking / data processing that happens between the drives.

A Bugatti Veyron's top speed is only 29mph when it's on a single-lane road stuck behind a moped, and in this case, your 5400rpm drive is that moped.
 
OK i think i'm getting it. the 5400 was the receiving hard drive, so i guess read/write max is about 80mb/s.

i had such high hopes for thunderbolt...
 
You would need at least two SSDs in RAID0 to be able to get close to maxing out the bandwidth on TB. Also it's important to remember, while USB3 is fast, it does not do well with high queue depths, as in random reads/writes. USB3 only performs well with sequential reads and writes, whereas TB performs extremely well even at high queue depths.
 
Babyboi said:
OK i think i'm getting it. the 5400 was the receiving hard drive, so i guess read/write max is about 80mb/s.

i had such high hopes for thunderbolt...
Click to expand...

Nothing wrong with the Thunderbolt in this case, it's your drives limiting things. Connect 2 decent SSDs and it'll be dramatically faster. Even if you moved data in the other direction with your existing setup (read from 5400 write to SSD) it should be faster.
 
Babyboi said:
OK i think i'm getting it. the 5400 was the receiving hard drive, so i guess read/write max is about 80mb/s.

i had such high hopes for thunderbolt...
Click to expand...

Nothing wrong with Thunderbolt. You just need an SSD RAID array to take full advantage of it if you want anything close to the theoretical transfer speed.
 
indeed, that 5400 rpm is the moped. SSD is just so expensive for what u get right now.
 
Babyboi said:
OK i think i'm getting it. the 5400 was the receiving hard drive, so i guess read/write max is about 80mb/s.

i had such high hopes for thunderbolt...
Click to expand...

your hopes should still be high, t-bolt is great when applied properly and it has bandwidth for the future.

Just wait till you can plug a PCI-E graphics card into an external tb enclosure and run games(if you're a gamer) 3 years from now on your MBP from this year.
 
I use a Pegasus R4 setup at work and it is worth every penny. The speed is insanely fast and am able to use it even with the 4 1TB 7200 RPM drives in RAID 1 extremely fast. It's setup as a shared drive among several of us that work with large video and photo files. Moving a 1gig file in mere seconds, I'll have to time it to get a true measure but I've loaded 6 to 7 gigs in less than 30 seconds, or so it seemed, to my retina MBP.

I've used it with a 7200 rpm drive and seem 100Mbps of solid speed when using super-duper to clone new iMacs in the office as well. I can say I wouldn't spend the money personally as It simply doesn't make sense for my back up solution when I can just start it and let it run over night. In a professional workplace, it is very much worth the price/speed ratio. My video guru loves his SSD based iMac with the Pegasus holding 4TB of storage for his Final Cut projects.
 
Babyboi said:
OK i think i'm getting it. the 5400 was the receiving hard drive, so i guess read/write max is about 80mb/s.

i had such high hopes for thunderbolt...
Click to expand...

Where Thunderbolt shines is in network transfers and video signal sending along with other data.

Thunderbolt is meant for multiple devices sending and receiving without there being a potential bottleneck.

One device will never max out Thunderbolt right now. (Unless it happens to be an SLC SSD x4 drive RAID 0 setup on both ends)
 
you will get better speeds if you just:

Buy a 2.5" laptop SSD.

Buy an external hard drive enclosure with either a USB 3/Thunderbolt connector.

Any thunderbolt external hard drive you buy only has a thunderbolt interface and inside it has a regular hard disk drive.
 
looks like thunderbolt is fast but it depends on your setup. thanks everyone for their input!
 
Babyboi said:
looks like thunderbolt is fast but it depends on your setup. thanks everyone for their input!
Click to expand...

That's how it is for every protocol you use. TB is about the interface, not the between.

"USB 3 is fast too but it depends on the setup. "

The reason people are excited about Thunderbolt is not because it is super fast, but because it makes your electronics a bit future proof for the next year. So, you're not stuck with slower interfaces and faster devices. Like I have 100MBps external hard drives but I can't use all of it because I got electronics with USB 2.0 ports. But now, finally, I can take advantage of those speed with both Thunderbolts and USB 3.0.

Your solid state drives will continue to get faster, hard drive RAID systems will get faster and so on but you need a much faster interfaces to take advantage of them.
 
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