I have a V240 with two CPUs, and 4x2GB and 4x1GB DIMMs. So I have
two options:

- Put 4x2GB into the 4 slots of CPU0 and 4x1GB into the 4 slots of
CPU1. This will give the best memory interleaving, but the CPUs
will have different amounts of "local" memory.

- Put 2x2GB and 2x1GB into each of the 4 slots for every CPU. This
gives worse interleaving, but the same amount of memory for each
CPU.

I do know that both CPUs can always all the memory, but the question
is whether it's better (performance-wise) to optimize interleaving,
or to reduce the possibility that a CPU has to access memory that is
available through the other CPU only.

Or doesn't it matter at all?

mp.
--
Systems Administrator | Institute of Scientific Computing | Univ. of Vienna
| http://www.par.univie.ac.at/solaris/pca/
Patch Check Advanced | Analyze, download and install patches for Sun Solaris

Hi,

Martin Paul wrote:
> I have a V240 with two CPUs, and 4x2GB and 4x1GB DIMMs. So I have
> two options:
>
> - Put 4x2GB into the 4 slots of CPU0 and 4x1GB into the 4 slots of
> CPU1. This will give the best memory interleaving, but the CPUs
> will have different amounts of "local" memory.
>
> - Put 2x2GB and 2x1GB into each of the 4 slots for every CPU. This
> gives worse interleaving, but the same amount of memory for each
> CPU.
>
> I do know that both CPUs can always all the memory, but the question
> is whether it's better (performance-wise) to optimize interleaving,
> or to reduce the possibility that a CPU has to access memory that is
> available through the other CPU only.
>
> Or doesn't it matter at all?
>
> mp.
Can the V240 use 4 DIMMS for interleave or only two, I though only two
and thats how I have configurated my systems(4GB on each CPU).

/michael

On Mar 23, 5:39 am, Michael Laajanen <michael_laaja...@yahoo.com>
wrote:
> Can the V240 use 4 DIMMS for interleave or only two, I though only two
> and thats how I have configurated my systems(4GB on each CPU).

Just checked the V240 at work and prtdiag -v indicates 4 way
interleave:

System Configuration: Sun Microsystems sun4u Sun Fire V240
System clock frequency: 167 MHZ
Memory size: 8GB
....
============================ Memory Configuration
============================
Segment Table:
-----------------------------------------------------------------------
Base Address Size Interleave Factor Contains
-----------------------------------------------------------------------
0x0 4GB 4 BankIDs 0,1,2,3
0x1000000000 4GB 4 BankIDs 16,17,18,19

Bank Table:
-----------------------------------------------------------
Physical Location
ID ControllerID GroupID Size Interleave Way
-----------------------------------------------------------
0 0 0 1GB 0,1,2,3
1 0 1 1GB
2 0 1 1GB
3 0 0 1GB
16 1 0 1GB 0,1,2,3
17 1 1 1GB
18 1 1 1GB
19 1 0 1GB

Memory Module Groups:
--------------------------------------------------
ControllerID GroupID Labels Status
--------------------------------------------------
0 0 MB/P0/B0/D0
0 0 MB/P0/B0/D1
0 1 MB/P0/B1/D0
0 1 MB/P0/B1/D1
1 0 MB/P1/B0/D0
1 0 MB/P1/B0/D1
1 1 MB/P1/B1/D0
1 1 MB/P1/B1/D1

David Wilson <mcs6502@gmail.com> wrote:
> On Mar 23, 5:39 am, Michael Laajanen <michael_laaja...@yahoo.com>
> wrote:
>> Can the V240 use 4 DIMMS for interleave or only two, I though only two
>> and thats how I have configurated my systems(4GB on each CPU).
>
> Just checked the V240 at work and prtdiag -v indicates 4 way
> interleave:

Yes, a similar situation here:

ID ControllerID GroupID Size Interleave Way
-----------------------------------------------------------
0 0 0 1GB 0,1
1 0 0 1GB
16 1 0 512MB 0,1,2,3
17 1 1 512MB
18 1 1 512MB
19 1 0 512MB

So the original question still remains ..

mp.
--
Systems Administrator | Institute of Scientific Computing | Univ. of Vienna
| http://www.par.univie.ac.at/solaris/pca/
Patch Check Advanced | Analyze, download and install patches for Sun Solaris

On Mar 23, 6:39 am, Martin Paul <m...@par.univie.ac.at> wrote:
> David Wilson <mcs6...@gmail.com> wrote:
> > On Mar 23, 5:39 am, Michael Laajanen <michael_laaja...@yahoo.com>
> > wrote:
> >> Can the V240 use 4 DIMMS for interleave or only two, I though only two
> >> and thats how I have configurated my systems(4GB on each CPU).
> > Just checked the V240 at work and prtdiag -v indicates 4 way
> > interleave:
> Yes, a similar situation here:
> ID ControllerID GroupID Size Interleave Way
> 0 0 0 1GB 0,1
> 1 0 0 1GB
> 16 1 0 512MB 0,1,2,3
> 17 1 1 512MB
> 18 1 1 512MB
> 19 1 0 512MB
> So the original question still remains ..

I doubt it would make a significant difference either way...
But to be consistent I suppose Id be tempted to make both
CPU banks the same, or get 4 more 1 GB SIMMS

HI,

Martin Paul wrote:
> David Wilson <mcs6502@gmail.com> wrote:
>
>>On Mar 23, 5:39 am, Michael Laajanen <michael_laaja...@yahoo.com>
>>wrote:
>>
>>>Can the V240 use 4 DIMMS for interleave or only two, I though only two
>>>and thats how I have configurated my systems(4GB on each CPU).
>>
>>Just checked the V240 at work and prtdiag -v indicates 4 way
>>interleave:
>
>
> Yes, a similar situation here:
>
> ID ControllerID GroupID Size Interleave Way
> -----------------------------------------------------------
> 0 0 0 1GB 0,1
> 1 0 0 1GB
> 16 1 0 512MB 0,1,2,3
> 17 1 1 512MB
> 18 1 1 512MB
> 19 1 0 512MB
>
> So the original question still remains ..
>
> mp.

I should put the same amount of RAM on each CPU even though the memory
performance is not as good as it can be.

I think that if a process is on a CPU which lacks RAM the latence would
hurt more than worse interleave.

/michael