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GIGABIT LAN bottleneck?

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Anonymous
a b G Storage
January 31, 2005 8:54:52 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Will I experience significantly faster exchange on my home LAN then with
100baseT thats there now?
Is there a bottle neck limitation in the PC that limits the max amount of
effective throughput to the point where it wont make much difference to hang
a GIGABIT LAN around it?
I have 4 PCs on a home LAN I was considering doing this for to improve HD
backup times I do to a server and to help with other shared bandwidth issues
we are starting to see with the kids playing online games, backups and such.

Any thoughts to suggest if this its worth the trouble to swap out NICs and
router to the GIGBIT world?.

Thank for any insights

More about : gigabit lan bottleneck

Anonymous
a b G Storage
February 1, 2005 3:33:37 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

jtsnow wrote:

> Will I experience significantly faster exchange on my home LAN then with
> 100baseT thats there now?
> Is there a bottle neck limitation in the PC that limits the max amount of
> effective throughput to the point where it wont make much difference to
> hang a GIGABIT LAN around it?
> I have 4 PCs on a home LAN I was considering doing this for to improve HD
> backup times I do to a server and to help with other shared bandwidth
> issues we are starting to see with the kids playing online games, backups
> and such.
>
> Any thoughts to suggest if this its worth the trouble to swap out NICs and
> router to the GIGBIT world?.

A good PCI-based server with a fast disk subsystem can sustain about 400
Mb/sec on a Gigabit LAN. First thing to determine is if you are hitting
100 Mb/sec--if you're not close to that then gigabit won't help, if you are
then it likely will.

>
> Thank for any insights

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
February 1, 2005 5:32:49 AM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

jtsnow wrote:
> Will I experience significantly faster exchange on my home LAN then with
> 100baseT thats there now?
> Is there a bottle neck limitation in the PC that limits the max amount of
> effective throughput to the point where it wont make much difference to hang
> a GIGABIT LAN around it?
> I have 4 PCs on a home LAN I was considering doing this for to improve HD
> backup times I do to a server and to help with other shared bandwidth issues
> we are starting to see with the kids playing online games, backups and such.
>
> Any thoughts to suggest if this its worth the trouble to swap out NICs and
> router to the GIGBIT world?.
>
> Thank for any insights
>
>
If my experience is any indicator, you will get a modest increase in
throughput.

I believe the PCI bus in most PCs is a bottleneck when gigabit speeds
are involved.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
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Anonymous
a b G Storage
February 1, 2005 3:47:39 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Previously J. Clarke <jclarke@nospam.invalid> wrote:
> jtsnow wrote:

>> Will I experience significantly faster exchange on my home LAN then with
>> 100baseT thats there now?
>> Is there a bottle neck limitation in the PC that limits the max amount of
>> effective throughput to the point where it wont make much difference to
>> hang a GIGABIT LAN around it?
>> I have 4 PCs on a home LAN I was considering doing this for to improve HD
>> backup times I do to a server and to help with other shared bandwidth
>> issues we are starting to see with the kids playing online games, backups
>> and such.
>>
>> Any thoughts to suggest if this its worth the trouble to swap out NICs and
>> router to the GIGBIT world?.

> A good PCI-based server with a fast disk subsystem can sustain about 400
> Mb/sec on a Gigabit LAN. First thing to determine is if you are hitting
> 100 Mb/sec--if you're not close to that then gigabit won't help, if you are
> then it likely will.

I did measurements on this some time ago. PCI card in several
different mainboards: 250-350Mb/s. Special combination (tested
in c't): 450Mb/s in a slot where the IRQ had other devices on it,
600Mb/s with its own IRQ. Both under Linux (the MB is not sold
anymore so no point in posting which it was). Measurements
were without disk load.

Whether an on-board card is on the PCI-bus or on something faster
depends.

Also around 600Mb/s with a 64bit PCI card in a 64bit/66MHz PCI bus.

Bottom-line: For higher performance you need something else than
normel PCI or _very_ careful tuning. You can get 250-350Mb/s by
just using a generic, low-cost card in a PCI slot.

For your HD backup, if the disk system is fast (say, 40MB/s
= 400Mb/s, including overhead), you begin to go into
the range where the PCI bus matters. Of course it depends
also on you networking stack and other OS-dependent factors.

I would say by just using generic GbE cards you should
get at least a speed-up of x 2, unless your OS or disks
are really slow. No promises though.

One thing that is nice about GbE is that all ports are symmetrical,
i.e. no need for cross-over cables anymore.

You should also use Cat 5e cable for all lines longer than
a few meters and need 8-lane cables for all lines, otherwise
they will drop back to 100Mb/s.

Arno
--
For email address: lastname AT tik DOT ee DOT ethz DOT ch
GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
"The more corrupt the state, the more numerous the laws" - Tacitus
Anonymous
a b G Storage
February 1, 2005 3:54:21 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"CJT" <abujlehc@prodigy.net> wrote in message news:41FEEA51.1000700@prodigy.net
> jtsnow wrote:
> > Will I experience significantly faster exchange on my home LAN then with
> > 100baseT thats there now?
> > Is there a bottle neck limitation in the PC that limits the max amount of
> > effective throughput to the point where it wont make much difference to hang
> > a GIGABIT LAN around it?
> > I have 4 PCs on a home LAN I was considering doing this for to improve HD
> > backup times I do to a server and to help with other shared bandwidth issues
> > we are starting to see with the kids playing online games, backups and such.
> >
> > Any thoughts to suggest if this its worth the trouble to swap out NICs and
> > router to the GIGBIT world?.
> >
> > Thank for any insights
> >
> >
> If my experience is any indicator, you will get a modest increase in
> throughput.
>
> I believe the PCI bus in most PCs is a bottleneck when gigabit speeds
> are involved.

Not if only one of the interfaces (whether source or destination device)
is on the PCI bus.
Anonymous
a b G Storage
February 1, 2005 4:56:22 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

"CJT" <abujlehc@prodigy.net> wrote in message
news:41FEEA51.1000700@prodigy.net...
> jtsnow wrote:
>> Will I experience significantly faster exchange on my home LAN then with
>> 100baseT thats there now?
>> Is there a bottle neck limitation in the PC that limits the max amount of
>> effective throughput to the point where it wont make much difference to hang
>> a GIGABIT LAN around it?
>> I have 4 PCs on a home LAN I was considering doing this for to improve HD
>> backup times I do to a server and to help with other shared bandwidth issues
>> we are starting to see with the kids playing online games, backups and such.

>> Any thoughts to suggest if this its worth the trouble to swap out NICs and
>> router to the GIGBIT world?.

> If my experience is any indicator, you will get a modest increase in
> throughput.
>
> I believe the PCI bus in most PCs is a bottleneck when gigabit speeds are
> involved.

And even when going from 10Mb to 100Mb the difference
doesnt exactly blow your sox off with most real world situations.

The only thing I do much that is theoretically affected is doing
imaging to a drive on the other side of the lan and none of the
current imaging apps like ghost or true image get even close
to saturating the lan link even with 100Mb.
Anonymous
a b G Storage
February 1, 2005 4:56:23 PM

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

very nice insight. Sounds like not worth the expense for me until I get a
PC that can handle the interface speed.

"Rod Speed" <rod_speed@yahoo.com> wrote in message
news:3689eoF4u818vU1@individual.net...
>
> "CJT" <abujlehc@prodigy.net> wrote in message
> news:41FEEA51.1000700@prodigy.net...
>> jtsnow wrote:
>>> Will I experience significantly faster exchange on my home LAN then with
>>> 100baseT thats there now?
>>> Is there a bottle neck limitation in the PC that limits the max amount
>>> of effective throughput to the point where it wont make much difference
>>> to hang a GIGABIT LAN around it?
>>> I have 4 PCs on a home LAN I was considering doing this for to improve
>>> HD backup times I do to a server and to help with other shared bandwidth
>>> issues we are starting to see with the kids playing online games,
>>> backups and such.
>
>>> Any thoughts to suggest if this its worth the trouble to swap out NICs
>>> and router to the GIGBIT world?.
>
>> If my experience is any indicator, you will get a modest increase in
>> throughput.
>>
>> I believe the PCI bus in most PCs is a bottleneck when gigabit speeds are
>> involved.
>
> And even when going from 10Mb to 100Mb the difference
> doesnt exactly blow your sox off with most real world situations.
>
> The only thing I do much that is theoretically affected is doing
> imaging to a drive on the other side of the lan and none of the
> current imaging apps like ghost or true image get even close
> to saturating the lan link even with 100Mb.
>
!