[CentOS] CentOS 64 on AMD 64 4600x2

Wed Jan 4 15:47:51 UTC 2006
Bryan J. Smith <thebs413 at earthlink.net>

Brandon wrote:
> Hello you brilliant minds,
> I am in need of some (probably basic) information
> CentOS and the new dual core 64 bit systems.  I realize
> Linux was inherently built for multiple processor systems,
> well as 64 bit systems.  My first question is AMD doing 
> anything special with doing all of the above on one chip
> that I need to know about before installing CentOS on my
> newest system? 

Both AMD and Intel do their best to "hide" any hardware
changes that are not compatible with legacy GTL+ through
various support chips, and those interface appear "standard"
in the APIC registers. 

In the case of AMD, they virtualized the GTL+ "bus" back with
the adoption of the Alpha EV6 architecture/interconnect
"switch" with the original Athlon.  They have gone to a true,
"partial mesh" in the Athlon64/Opteron, but it all still
appears as a GTL+ "bus" from the standpoint of Linux
(although the Linux kernel does have some modifications for
better efficiency of the architecture).

The AMD dual-cores are actually interconnect almost the
_exact_same_ as if they were two seprate sockets, from an
electrical/logic standpoint.  There are only a few
performance considerations (both pro and con) of the
dual-core v. two sockets.

In the case of Intel, still using the GTL+ "bus," so they
have had to add a _lot_ of bridging in the new dual-cores. 
There's a lot of commentary on this, because Intel is
releasing a better dual-core this year (mid-2006).  But the
underlying architecture is radically different for Intel
separate cores v. dual or multicore.  Intel is close to
introducing multiple front-side busses for its server chips
with a switching interconnect -- much like old Alpha EV6
(which 32-bit Athlon used).

> Also, my motherboard being a a8n32-sli has SATA II

Which is largely a marketing term:  

SATA-IO is what you want, otherwise, SATA-II without SATA-IO
is kinda like USB 2.0 without EHCI.  Most of the benchmarks
have no clue, because the drives can't break 150MBps yet --
so they can only give artificial numbers of what the chip is
actually capable of when the signal has to traverse cabling
only designed for 1.5GHz.  ;->

> and RAID

FRAID (Fake RAID).  Disable it.

> capabilities.  Is there anything special about the SATA II
> that I need to set up to use the full capabilities of this
> hardware and CentOS.  Any information would be better than
> what I have at the moment.

I haven't seen anything on SATA-IO developments so, again,
SATA-II is rather a lot of marketing baloney at this point. 
The SATA-II chip is allegedly capable of 3GHz.  The SATA-II
drive is allegedly capable of 3GHz.  But I've seen nothing to
the 3GHz SATA-IO standard as specified by the ATA committees.

Bryan J. Smith     Professional, Technical Annoyance                      b.j.smith at ieee.org      http://thebs413.blogspot.com
*** Speed doesn't kill, difference in speed does ***