Gigabit Ethernet, what speed should it be really?

[virulosity]

I just bought a second computer, both of my machines have Gigabit network adapters. So I went and bought a 5 port gigabit switch and a pair of CAT6 cables to see what kind of transfer speeds I could get. I am only getting 11MB/s when transferring files. If I multiply by 8, this is only 88Mb/s, less than a 10/100 connection. So what gives?

[armygunsmith]

I suppose you might be limited by the speed you drive can perform write operations.

[spsellars]

Just because your NIC can transfer at 1Gbps doesn't mean your hard drives can. Ideally you should be at ~90% transfer speed of whatever the slowest drive in the chain is capable of.

[virulosity]

Both machines have Sata 150 connections for hard disks, If i do a file copy on one of the machines I get over 80MB/s.

[virulosity]

OK, I did a copy on the other machine and that is the problem, its only 11MB/s write speed. I guess that solves it. Aren't SSD's slower at writing than conventional platter HD's?

[spsellars]

Both machines have Sata 150 connections for hard disks

Unfortunately, what the controller and cables are capable of have nothing to do with what the hard drive itself can do. (Your drive is not even coming close to saturating your SATA controller; that's why most motherboards get away with splitting that bandwidth between all drives on that controller.)

Aren't SSD's slower at writing than conventional platter HD's?

Entirely depends on which drives you're comparing, and how they're set up. Though all else being equal, a random write will generally be (considerably) slower on a Flash SSD than a random write on a platter. Newer SSD and hybrid drives alleviate that somewhat.

[virulosity]

Its interesting to me that when these standards were designed, there is such a big margin over the performance of the drives, or are my drives just slow? I guess there are SCSI or RAID systems out there that can fill the void?

[odysseus]

Its interesting to me that when these standards were designed, there is such a big margin over the performance of the drives, or are my drives just slow? I guess there are SCSI or RAID systems out there that can fill the void?

Gig ethernet was not derived with throughput strictly for your home network copying to your IDE (then) or SATA (now) PC drive. As you elude to, back years ago when first put into network products they were back end aggregation for 100mb switches. Also servers utilize it for multi-node access, to which not all is dependent on disk I/O, even if the disk I/O is very fast RAID striping on very fast BUS architecture. iSCSI has utilized it as well, which has fetched 10Gb and 40Gb ethernet standards to compete with gig fiber channel.

However it is much of an improvement over 100mb speeds nonetheless for the home. I have been gig-e for a long time. The issue being arrived at in the conversation is that from the nic through to the head writing on the platter, there are issues in the layers from application through physical BUS that can inhibit speed. Since 100 ether is only around 12MB/s, you will need 1000 to get to the upper limits of your PC disks I/O.

[JDay]

Both machines have Sata 150 connections for hard disks, If i do a file copy on one of the machines I get over 80MB/s.

Those are first generation SATA drives, not exactly fast. You should upgrade to SATA-II (3 Gb/s) or SATA-III (6 Gb/s). Your drives probably don't even support NCQ. You should also make sure you're running them in AHCI mode and not IDE emulated mode. The setting for this is in your BIOS, however if it is not already set to AHCI you'll have to reinstall your OS when you change it.

[Corbin Dallas]

Those are first generation SATA drives, not exactly fast. You should upgrade to SATA-II (3 Gb/s) or SATA-III (6 Gb/s). Your drives probably don't even support NCQ. You should also make sure you're running them in AHCI mode and not IDE emulated mode. The setting for this is in your BIOS, however if it is not already set to AHCI you'll have to reinstall your OS when you change it.

This ^^^^


Also, you mentioned your router and ethernet cards, what about your modem? Is it gigabit capable?

[virulosity]

My gateway isn't gigabit, but the switch that these devices are attached to (downstream of gateway) is gigabit. I will check into the AHCI setting. Thanks

[FluorideInMyWater]

cat6 is not capable of handling gigabyte traffic. u need fiber for it.
check the listing below

HSDPA (cat.6) conversion chart
Data transfer rate, Computer Connection Speed
One HSDPA (cat.6) is equal to:

Basic Units of Data Transfer Rate
terabit per second 3.6 *10-06
gigabit per second 0.0036
megabit per second 3.6
kilobit per second 3600
bit per second 3600000


Byte-based Transfer Rate Units
terabyte per second 4.092726 *10-07
gigabyte per second 0.0004190952
megabyte per second 0.4291534
kilobyte per second 439.4531
byte per second 450000

[Stockton]

We have several customers using gig e via cat6 circuits. It's capable.

[odysseus]

cat6 is not capable of handling gigabyte traffic. u need fiber for it.
check the listing below

You need to expand on the conversation. There are different standards for what is "Gig E", and one of these standards is capable over cat5e and cat6 copper. True performance throughput and strand lengths are certainly better qualified on fiber optic standards.

https://secure.wikimedia.org/wikipedia/en/wiki/Gigabit_Ethernet

[bbguns44]

"cat6 is not capable of handling gigabyte traffic. u need fiber for it."

Wrong. Cat 6 runs Gb with no problem. Any limitations are due to
slow software.