[Pc_Support] Re: LUNA: Re: 68-pin SCSI card for Linux box .... -- i865/875 = desktop (not workstation/server)

[William A. Mahaffey III]

Bryan J. Smith wrote:

>On Tue, 2006-06-27 at 17:29 -0500, William A. Mahaffey III wrote:
>  
>
>>I understand this point quite well, how do I check that ? I have 3
>>HDD's hooked up to the onboard (Foxconn 865A-01 i865 mbd) IDE
>>controller, I didn't think that they went through the PCI bus, just
>>other peripherials (NIC's, for example).
>>    
>>
>
>_All_ Intel i8xx series MCH designs have a single ICH that connects via
>a 64-bit at 66MHz (533MBps) PCI bus.  Then virtually _all_ peripherals use
>a _shared_ 32-bit at 33MHz (133MBps) PCI bus that is bridged to the ICH's
>533Mbps uplink to the MCH.  The NIC may or may not be such -- depending
>on the ICH.  I'm quite sure _all_ ATA (and SATA) channels are "shared"
>on that 32-bit at 33MHz (133MBps) bus.
>
>That's because *100%* of i8xx systems are designed for _desktop_ usage,
>_not_ server (or even workstation for that matter).  Anyone who tells
>you otherwise should be slapped silly.
>
>Intel's "equivalent generation" workstation/entry-server chipset is the
>E72xx series with an _optional_ Intel 6x00 PCI64/PCI-X series hub
>_separate_ from the ESB6300 ICH (the workstation/server equivalent of
>the i8xx ICH).  Their professional server chipset is the E75xx series.
>Both are based on the ServerWorks ServerSet III/IV "Grand Champion" (GC)
>PCI64/PCI-X bridging.
>
>The newer i9xx series MCH designs have a single ICH that connects via
>4-8 PCIe channels.  Several of those channels are often used for NIC and
>SATA channels.  In addition to the E723x/753x series workstation/server
>chipsets with PCIe (as well as with optional 6700 PCI-X bridge), there
>is a new Intel 5000 series that natively does PCIe (with optional 6700
>PCI-X bridge).
>
>[ NOTE:  We've covered this before.  The i865/875 has only 1/8 - 1/16th
>the bridged PCI I/O of _any_ E72xx/75xx chipset.  The i865 should
>_never_ be used in a production environment and the i875 is definitely a
>_desktop_ only chipset.  Do not use it as a power workstation or not
>even as an entry server. ]
>
>  
>
>>I am backing stuff up from the HDD's on *this* box to the new tape
>>drive, *after* this box gathers its near-line backup over the network
>>from the other 4 boxen. I just ordered the above card, BTW, thanx :-).
>>    
>>
>
>But understand, the transfer still requires _separate_ transfers for:  
>- Disc to memory
>- Memory to tape
>
>So 2x the transfer.  For LTO-1, you're probably okay as long as the
>system is doing _nothing_ else.  But for LTO-2, you're definitely
>saturating the 32-bit at 33MHz PCI badly.
>  
>

OK .... so for an LTO-1, on an *IDLE* system (1:45 AM, nobody logged on) 
working alone (*not* across an NIC), I should be AOK, oui ?

-- 
	William A. Mahaffey III

 ----------------------------------------------------------------------

	"The M1 Garand is without doubt the finest implement of war
	 ever devised by man."
                           -- Gen. George S. Patton

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.matrixlist.com/pipermail/pc_support/attachments/20060627/314cf8fc/attachment.html