[K12OSN] Re: Networking a new school for K12LTSP?

[Petre Scheie]

Terrell Prudé Jr. wrote:
> Robert Arkiletian wrote:
>> On 1/31/07, Robert Arkiletian <robark at gmail.com> wrote:
>>> On 1/31/07, Petre Scheie <petre at maltzen.net> wrote:
>>>> Terrell Prudé Jr. wrote:
>>>>> Robert Arkiletian wrote:
>>>>>> On 1/29/07, Joseph Bishay <joseph.bishay at gmail.com> wrote:
>>>>>>> Hello,
>>>>>>>
>>>>>>> I hope you are doing well.
>>>>>>>
>>>>>>> Thank you all for the comprehensive reply!
>>>>>>>
>>>>>>> Once I started reading your email, I realized that probably the
>>> best
>>>>>>> way to proceed was to work with the idea of NIC Bonding or port
>>>>>>> trunking.  I have a surplus of Gigabit cards so I could put 3 in a
>>>>>>> server (reading online I found that more than 3 wasn't going to
>>> give
>>>>>>> enough of an improvement due to the PCI bus limitations -- can
>>> anyone
>>>>>>> validate this?) and then send all 3 of those to the switch. I
>>> could
>>>>>>> then bond 3 ports from that switch to the next one (we'll probably
>>>>>>> have 2 x48 gigabit switches for the whole building -- still
>>> counting
>>>>>>> the number of ports/computers required) so as to deal with the
>>>>>>> bandwidth.  The cost of some of those fiber <-> copper converts
>>> look
>>>>>>> rather daunting.
>>>>>>>
>>>>>>> I would VERY MUCH prefer to use only 1 server for the entire
>>> building
>>>>>>> -- I am still very much a novice at this and the complexities of
>>>>>>> setting up multiple servers or splitting into application &
>>> /home with
>>>>>>> LAPD sounds rather daunting.
>>>>>>>
>>>>>> If your still set on one server also have a look at this
>>>>>> http://k12ltsp.org/mediawiki/index.php/Technical:Subnetting
>>>>>> Instead of port trunking I think this would be a better idea.
>>>>>> Especially if you are going to have 2 48 port switches that
>>> could be
>>>>>> on different gigabit linked subnets.
>>>>> Hmm...I hadn't thought of that particular application
>>> myself--addressing
>>>>> bandwidth bottlenecks--but you're right, that sure would do it! 
>>> That
>>>>> never even occurred to me...thanks!
>>>>>
>>>>> --TP
>>>> I recall reading somewhere that three gigabit cards is probably the
>>> max that the PCI bus
>>>> can handle.  Can anyone confirm or deny this?
>>> No. A gigabit card is 1 Gibabit/s (that's 1 billion bits per second).
>>> Each byte is 8 bits. So  it maxs out at 125MB/s. A simple PCI bus can
>>> handle 133MB/s max. So 1 gigabit ethernet card can saturate a PCI bus
>> Correction:
>> PCI 2.2 spec is 32 bits at 66Mhz which equals 266MB/s.  So 2 gigabit
>> nics should be able to saturate it. The original PCI bus was 32bits at
>> 33Mhz which is 133MB/s.
>>
> 
> True, but if your PCI bus is 64-bits at 66MHz (i. e. PCI-X), then you're
> fine, as you then have 532MB/s.  I've always been sure to buy 64-bit,
> 66MHz NIC's for this reason.  Same with RAID cards; PCI-X whenever possible.
> 
What brand of 64-bit NIC are you buying for this purpose?  Where do you get them?

Petre