Re: MSI K8N Neo2 For Dual Core?

On Tue, Aug 23, 2005 at 08:17:06PM -0500, Bryan J. Smith wrote:
> On Tue, 2005-08-23 at 19:59 -0400, Robert L Cochran wrote:
> > I finally found the courage to upgrade my MSI K8N Neo2 Platinum 
> > (MS-7025) BIOS to version 1.9 which I believe supports AMD 64 dual-core 
> > CPUs. I'm thinking of actually buying such a CPU. Does it makes more 
> > sense to replace this motherboard with a new one that might be better 
> > suited to dual-cores?
> 
> Unless the BIOS doesn't enable it, there's virtually _no_ benefit when
> it comes to AMD.  The package has DDR out, HyperTransport out, no change
> in that.

Agreed.

> In Athlon 64 / Opteron, the memory timing no longer affects any other
> part or the system.  So you can use anything, from DDR200 (PC1600) to
> DDR400 (PC3200).  So in addition to fundamental size issues, the only
> restriction is Registered/Buffered for Socket-940, Unbuffered for
> Socket-754/939.

Correct, the dimms are directly attached to the CPU, but of course
PC1600 will result in a system with a slower memory bus than PC3200.
Thus if you have PC1600 you will get a smaller increase in performance
with a X2 processor than you would if you had PC3200 since more often
(statistically) you will be bottlenecked by the PC1600 memory and thus
deriving no benefit from your second CPU.

Personally I'm not ready to buy an X2 for home yet, I have PC3200 memory
and a AMD64 3200, it's plenty fast for what I use it for and $380 for
a x2 3800 (or more for faster) is a fair amount of cash for something
that won't run a single thread any faster than my current machine.
Not that I don't sometimes have a 2nd thread running, it's just not at
the $380 pain threshold yet.

So at some point it's better to hold off and hit whatever knee in the
price/performance curve you want with a new CPU+Motherboard and maybe
RAM combination.

Rumors claim DDR2 for AMD64 in 2006, possibly linked to the rumored
1200+ pin socket and onchip pci-e.  It should be an interesting
platform and will be the earliest time that I revisit an upgrade.

I try to wait till what I can afford doubles end user performance,
so far:
  286     6 Mhz
386sx    16 Mhz
386dx    40 Mhz
P5      133 Mhz
P6      200 Mhz
celeron 450 Mhz
Athlon 1200 Mhz
Amd64  2000 Mhz

I suspect it's going to be awhile before I can find a machine
twice as fast as my current for a reasonable (to me) amount of
money.

-- 
Bill Broadley
Computational Science and Engineering
UC Davis