ES80 Mod4 to Mod 6 upgrade

[Howard_24]

We just got in a ES80 Mod 2 upgrade with 2 cpu's and no memory. Can I use this to upgrade my existing ES80 Mod 4 to a Mod 6 without there being memory in the Mod 2 upgrade drawer or will I have to take memory out of one of the other 2 drawers. The thing is there is 16gig of memory so it will be hard to evenly spread out the memory.

Thanks,

Howard

[Hein van den Heuvel]

Tru64 is Numa aware. It has several techniques to use 'cell local memory' or 'rad awareness' in order to avoid remote memory access.
- kernel text replication
- program text replication
- scheduler 'gravity'
- read-mostly memory clones
- write-mostly memory localication + accumulate
- RAD local mallocs
- RAD local stack
All of those can only work when there is actual memory to play with!

Like you, I would prefer to keep the first QBB filled with CPUs and add 2 CPU + 2 memroy modules to the second QBB. This would give you 2/3 odds that a randomly allocated memory location is local.

However, if you do not have the memory, then i believe it to be better to allow the kernel to do some Numa optimization and thus I would suggest 3 CPU + 8GB in each QBB. This will give 1/2 odds, for those random memory accesses, but much more will become local.

Please do confirm with support/sales
Regards,
Hein.

[Erich Wimmer]

Hein,
you are talking about GS80 and not ES80, did you know the config. rules for ES80 too ? (unfortunately I don't).
Erich. :-)

[Hein van den Heuvel]

Argh, yes I was thinking GS80 with its 2 QBBs each up to 4 CPUs.
Sorry 'bout that!

The ES80 is 'split' into 2-CPU drawers, and normally as single-cpu RAD. The numa effects are there, but very soft (10 times less important than on the GS80).

I believe folks indeed run them with memory-less cpu's, but I don't like that feeling.
I never really studied it, because I would not run it that way. I'll see if I can find a clear whitepaper.

In this case I would probably configure 2-Cpus-each-4GB, and 4-Cpus-each-2GB for 6 CPUs and 16GB. This is ASSUMING that incremental interleaving will offset the disbalanced configuration.
There are probably rules forcing an 'even' number of GB/cpu, unless you have very small memory sticks. If you can freel mix (I doubt) without interleaving penalty then I supposed you should consider 4*3+2*2. Unlikely!

Hein.

[Hein van den Heuvel]

Well, a qucik search for 'alphaserver' on the hp.com website soon leads to

http://h18002.www1.hp.com/alphaserver/es80/
which has:
http://h18000.www1.hp.com/products/quickspecs/11922_na/11922_na.PDF
which reads:

Step 4 - Memory Options â Mandatory
Configuration Guidelines

Mandatory selection of at least one memory option per Dual CPU Building Block Module.
1. Each CPU supports one or two memory options.
2. Both options must be the same size for a CPU, but different size options can be used on different CPUs.
3. If an I/O Expansion Drawer is ordered (Step 6), both CPUs in the CPU Building Block Module connected to the I/O Drawer must have at least one memory option.
4. Each memory option consists of four RDRAM Inline Memory Modules (RIMMs).
:

Hei