Home gigabit network throughput?

ChrisLX200 · 3 Apr 2006 at 12:36

What can I realistically expect in terms of throughput from a home gigabit network? Best I ever see is around 175mbps - a long way off 1000mbps.
I'm using Cat5e cabling but have just ordered some Cat6 patch leads in case that might help.

encephalopathy · 3 Apr 2006 at 13:28

here you go
i was in a similar boat a wee while back
http://forums.overclockers.co.uk/showthread.php?t=17539975

sja360 · 3 Apr 2006 at 13:42

encephalopathy said:
...

what hard drive is it you have?

ChrisLX200 · 3 Apr 2006 at 18:55

encephalopathy said:
here you go
i was in a similar boat a wee while back
http://forums.overclockers.co.uk/showthread.php?t=17539975

OK thanks I had a read through that. Tested mine and I only get 30MB/s (according to SiSoft Sandra) - it's around half what it should be. I should get the new cables tomorrow so I'll see if that does anything. I'm using the Marvel onboard connections on two computers, but do have some DLink 530T NICs I can try.

Amoeba · 3 Apr 2006 at 19:05

Could be the speed of your HDD holding you back..

sja360 · 3 Apr 2006 at 19:47

cant the raptors do 50MB/sec sustained? so infact you could use about jus over half the bandwidth with them?

E1mo · 3 Apr 2006 at 20:47

Surely these network interface testers should be doing some kind of copy from memory? (eg. not limited by HDD speed)

encephalopathy · 3 Apr 2006 at 21:24

that was from 7200rpm ide to 7200rpm sata

i now have a 74gb raptor but haven't rerun things

to be honest it really is sooo much quicker than the 10/100 connection i had before - it is swings and roundabouts as to whether unraring via remote desktop in the attic and transferring down is any quicker than going via network share downstairs, unraring and transferring

sja360 · 3 Apr 2006 at 21:55

yea it'll be very atleast double the speed of a 100mbp network or i'd hope it would be

Vertigo · 3 Apr 2006 at 23:04

Mine maxes out at around 300Mpbs using non-HDD based bandwidth tests and I've never managed to work out why it's so slow.

Energize · 3 Apr 2006 at 23:08

Youll probably need raid to max out the bandwidth.

ste_bla · 3 Apr 2006 at 23:36

You need jumbo frames to get anywhere near the 1gbit speed iirc

Also how are the GB NIC connected?

Magsy · 4 Apr 2006 at 15:41

On a fairly decent network at work, Cisco 3750's, Intel/Broadcom cards and Dell Poweredge's running 5 drive RAID 5 the best we usually see is 300mbps. Quite often data transfer is only 20Mb/s....
On servers not running RAID 5 you can sustain 40-45Mb/s.

I have had a client over that though by pulling multiple streams from different servers. Topped out at 85Mb/s...

Fast clients, Pentium D with 15k scsi

In working environment you might need and use the bandwidth for applications/data running from ram/cache.

At home you are hard drive limited all the way!

Energize · 4 Apr 2006 at 15:53

Raid 1 and 0 are good for file transfers, the transfer speed is the total of all the drives added up.

ChrisLX200 · 5 Apr 2006 at 08:03

I tried the Cat 6 cables and they made no improvement, neither did using DLink 530T NICs instead of the onboard Marvel ports. Enabling Jumbo Frames (the gigabit switch supports this feature) caused no end of problems for WinXP and I was not able to test the benefits. Looks like I'm stuck with 29-30MB/s...

sja360 · 5 Apr 2006 at 11:55

ChrisLX200 said:
I tried the Cat 6 cables and they made no improvement, neither did using DLink 530T NICs instead of the onboard Marvel ports. Enabling Jumbo Frames (the gigabit switch supports this feature) caused no end of problems for WinXP and I was not able to test the benefits. Looks like I'm stuck with 29-30MB/s...

stuck with 30MB/sec? lol its just about double the transfer speed of 10/100. were you expecting nearer 50MB/sec i presume?

V-Spec · 5 Apr 2006 at 12:04

As its been said hundreds of times, your hdds will be the bottleneck, the max theoretical speed of 1Gb is 125MBps, problem is its ethernet so you only get 70% of that... your doing pretty well with 30MBps, I certainly wouldn't be complaining..

sja360 · 5 Apr 2006 at 12:08

V-Spec said:
problem is its ethernet so you only get 70% of that...

? how's that outta interest? i thought you could reach almost 100MB+/sec? or do you have to use fibre for reaching 100MB/sec +?

Skilldibop · 5 Apr 2006 at 12:16

175Mbit/s is about 21MB/s so it's well within your HDD spec, If your using a PCI adapter it could be lack of PCI bandwidth if you have a soundcard or whatever running. Could also be 40 conductor cable on your HDD instead of 80.

But you wont ever get 1000mbit. To answer the above post aswell you get about 70% throughput because only about 70% of an ethernet frame is actual usable data. The rest is ethernet and IP headers used by routers and switches to point the packets to where they need to do. Every bit used for headers is a couple of bps stolen from your throughput.

sja360 · 5 Apr 2006 at 12:19

Skilldibop said:
To answer the above post aswell you get about 70% throughput because only about 70% of an ethernet frame is actual usable data. The rest is ethernet and IP headers used by routers and switches to point the packets to where they need to do. Every bit used for headers is a couple of bps stolen from your throughput.

roger that skilldibop, cheerz