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GM7HUD > PC 08.06.08 12:23l 49 Lines 2606 Bytes #999 (0) @ WW
BID : CA5124GM7HUD
Read: GUEST
Subj: Re: GIGABIT Hub ?
Path: IZ3LSV<IW0QNL<OK4PEN<SV1CMG<DK0WUE<7M3TJZ<ZL2BAU<GB7ESX
Sent: 080608/0940z 13341@GB7ESX.#31.GBR.EU $:CA5124GM7HUD [Witham, Esx]NNA V3.1
G6KUI wrote:-
>
> Anyone got any advice on which gigabit hub to go for ?
They're pretty much all the same unless you are spending big money and
going for a managed one. There are only a few gigabit router chips used in
domestic routers. They all manage to cope with end to end gigabit transfer
on a single route. The difference comes when you have all the ports trying
to do transfers. Domestic routers tend to have insufficient b/w in those
cases but most of the time you have a few ports in use with just a little
background traffic and one big transfer running and they work fine there.
Watch out for is cable quality. Not all cables are created equal and
gigabit is really 4x 250mbps in parallel. It should work on a CAT5 cable
and CAT5e is a better choice. Some CAT5 cables are rubbish so you may need
to swap the pieces you are using if performance is poor.
> a PC and a network drive but in time I will be adding other faster kit.
Warning! Warning! Many pieces of hardware come with gigabit ethernet ports
but they can't really make full use of it. In theory using gigabit ethernet
between a pair of competent machines will let you see 80megabyte/second
file transfers using SMB/Samba drives maybe a little faster for NFS.
Typically you'll get 8 or 9megabyte/second using 100mb ethernet. However,
you need to ensure your drives can perform such sustained transfers or you
wont get that speed. My PC is slightly long in the tooth and uses PATA
drives. These top out at 50megabytes/second meaning that I cannot fully
saturate gigabit ethernet using this PC.
Network drives are reknowened for specmanship. I have one that has PATA and
gigabit. It only has a teeny cpu and whilst it is stunningly reliable (it's
on 24/7 serving webpages/SSH ) and acts a primary disk for the home network
it is a little underpowered. It can just achieve 43megabyte/second disk
transfers so on 100mb ethernet it can serve files as fast as any client can
request them. However, the CPU is too slow to really use gigabit as
transfers tend to max at 22megabytes/second. The CPU can't get the data
from the disk to the ethernet chips fast enough. So if use gigabit here I'd
only see a 2 and a bit times speed up, not worth the hassle. However, it
only uses about 12W of electricity so it is cheap to leave on all day
compared to a fast PC which would be nearer 80W.
You need to check your all the drives on all the machines you will use can
achieve gigabit type speeds and that all the machines have sufficient
horsepower to do sustained gigabit transfers or you'll not receive any real
benefit.
73 de Andy GM7HUD
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