Is there a speed scale between REAL LIFE speeds of data transfer tech?

[fuzzybabybunny]

Anything with solid MB/s transfer numbers?

 

[fuzzybabybunny]

🙁

 

[Never Knows Best]

http://forums.anandtech.com/messageview...atid=50&threadid=1942745&enterthread=y

That gives some numbers about transfer rates of ethernet transfers.

 

[ForumMaster]

FW is either 400Mbit or 800Mbit depending on what version,
USB 1 varied from 1.5Mbit up to 12Mbit
USB 2 clocks at 480Mbit
Gigabit Ethernet is really only 125MBps
Regular 100Mbit is the second slowest.
Ethernet can't quite keep up with drives from what i understand cause of the packets. and usualy it is connected to the PCI bus which can't saturate the connection.

Therefor, i think FW 800Mbit would be the fasest. but i think you may have a hard time finding drives that use this standard.

 

[Dman877]

Those are theoretical maximums. Actual transfer rates for most of those connections vary from 10 - 25% of the theoretical numbers (IE USB 2.0 connections usually max out for me around 40 mbps).

 

[Madwand1]

Wireless-g < Regular Ethernet < USB 2 < Firewire (400,800) < Gigabit.

For single drives, over gigabit, the drive is the biggest bottleneck, so the practical difference between higher-end fire wire and gigabit is usually not large.

Some rough numbers for actual large file transfers that I've done:

2 MB/s over "54 Mb/s" 802.11g wireless.
8-10 MB/s with regular 100 Mb/s Ethernet.
25 MB/s with USB 2.
30-45 MB/s with gigabit Ethernet using average single drives.
50-60 MB/s with gigabit Ethernet and fast regular drives in outer sectors.
60+ MB/s with gigabit Ethernet using RAID arrays.

~90 MB/s maximum to date with (RAID 5 to RAID 0 over consumer gigabit using client OSs).

Here are some else's numbers, including Firewire 400. Note that his test is flawed, probably because he uses files that are too small & fit in cache (as the author admits, with the 152 Mb/s fast Ethernet performance). However, it does have some representative value regardless, because it's the same flawed test over different interfaces.

http://wolfpaulus.com/journal/hardware/dts.html

In practice, performance varies a lot -- different USB 2 implementations, drives & file systems & file layouts, computers, system buses, chipsets, gigabit implementations, file transfer programs/protocols, and even direction of transfer, perform differently. The above numbers are representative of better-performing systems.

It's always possible to have something under-performing despite a "gigabit" label, etc. (I even describe many consumer NAS boxes as "fakegigabit"). It's impossible to hit the theoretical interface performance with actual file transfers, esp. so at the higher end of the speed limits where multiple bottlenecks come into play.

 

[ForumMaster]

Originally posted by: Dman877
Those are theoretical maximums. Actual transfer rates for most of those connections vary from 10 - 25% of the theoretical numbers (IE USB 2.0 connections usually max out for me around 40 mbps).

well ofcourse. i posted the theortical maximum that the connection support. gigabit ethernet is usually more in the vicinity of 600-675mbit on the PCI bus. although i must say that is have got upwards of 400Mbit when transferring things to my ipod. don't know why it's so slow for you.

the fastest drive connection would be raid of Ultra SCSI 320 drives i believe.

 

[fuzzybabybunny]

Originally posted by: ForumMaster

Originally posted by: Dman877
Those are theoretical maximums. Actual transfer rates for most of those connections vary from 10 - 25% of the theoretical numbers (IE USB 2.0 connections usually max out for me around 40 mbps).

well ofcourse. i posted the theortical maximum that the connection support. gigabit ethernet is usually more in the vicinity of 600-675mbit on the PCI bus. although i must say that is have got upwards of 400Mbit when transferring things to my ipod. don't know why it's so slow for you.

the fastest drive connection would be raid of Ultra SCSI 320 drives i believe.

I think Dman877's correcting you because I ask for real life transfer rates in my thread title 😛

 

[bob4432]

don't get Mb and MB mixed up. basically the Gbe in theory and in practice. i don't have any hard numbers but look at it this way-
if you are using 1394b it is 800Mb/s, but you need to see where it ties into a bus and which one. Gbe (1000Mb/s) is usually on a seperate bus than sata hdds, so there usually is not a bottleneck between the 2 except for single hdd setups - but put those in a striping raid and you can max it out which is ~100-125MB/s str - large files, not 10,000 50KB files - there you will only get a couple MB if you are lucky.

as far as the fasted hdd subsystem being u320, you also need to take into acct sas, which basically are cards that use sas (serial attached scsi so you can use the nice 15k one) and/or sata. nice setup and where stuff is going. the fastest current single u320/sas hdd in str are the current cheatah 15k.5 with it being over 100MB/s

 

[zephyrprime]

Originally posted by: Dman877
Those are theoretical maximums. Actual transfer rates for most of those connections vary from 10 - 25% of the theoretical numbers (IE USB 2.0 connections usually max out for me around 40 mbps).

You're wrong. Maximum real transfere speeds are less than datarate but it's not that low. I've tested within 85% on ethernet and 40MBps on USB.

Some of the bandwidth in connections is consumed by wait states, crcs, and protocol.

 

[bob4432]

Originally posted by: zephyrprime

Originally posted by: Dman877
Those are theoretical maximums. Actual transfer rates for most of those connections vary from 10 - 25% of the theoretical numbers (IE USB 2.0 connections usually max out for me around 40 mbps).

You're wrong. Maximum real transfere speeds are less than datarate but it's not that low. I've tested within 85% on ethernet and 40MBps on USB.

Some of the bandwidth in connections is consumed by wait states, crcs, and protocol.

i think he meant, at least the way i intrepreted it, was you will lose between 10-25% due to overhead, not that you will get 10-25% of the advertised bandwidth on the wired stuff.