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ES45 1B Memory Question

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MrEdu
Occasional Advisor

ES45 1B Memory Question

First let me start off that I am new to the alpha world and was given 4 - 1GB DIMMs to upgrade our ES45 1B system. Now sets 0,1,2,3 already have 4 - 256MB DIMMs. What is the recommended configuration to get the maximum amount of memory?
5 REPLIES
Steven Schweda
Honored Contributor

Re: ES45 1B Memory Question

MrEdu
Occasional Advisor

Re: ES45 1B Memory Question

Sorry I did go through the docs and I am just looking to confirm.

Current Setup
MMB0 - 4 x 256 = 1GB
MMB1 - 4 x 256 = 1GB
MMB2 - 4 x 256 = 1GB
MMB3 - 4 x 256 = 1GB

Now I am looking to replace a set of 4 x 256 with 4 x 1GB DIMMs. Which Bank is the best and supported to pull out and replace to get the max memory.

From what I read would be to pull out MMB1 and replace with the 4 - 1GB DIMMs and then leave MMB3 Empty. This would give me a tolal of 6GB. Is that correct or can I just take out MMB3 and swap the 256 with the 1GB for a total of 7GB.

These are fantastic forums!

Thanks!
From MrEdu
Rob Leadbeater
Honored Contributor

Re: ES45 1B Memory Question

Hi,

The usual best practice is to put the largest DIMMs in the lowest bank, so put your 4 new DIMMs in bank 0. The configuration rules are normally printed on the inside of the system cover.

Note however that whatever you do, you'll change the memory interleaving from 4-way, which may have an effect on the memory speed...

Hope this helps,

Regards,

Rob
Hein van den Heuvel
Honored Contributor
Solution

Re: ES45 1B Memory Question

From the links Steven provided you can find the owners guide which in chapter 4.9 extensively documents the process:
http://h18002.www1.hp.com/alphaserver/download/ek-es450-ug-b01.pdf

Nothing to add really: tables, pictures, rules.

Sounds like you have the 4 bank, 16 dimm configuration right?

With the 32 dimm config you should fill 0 and 4 and 1 and 5 with 256 DIMSM to get those to interleave and stick the 4-1GB DIMMs in 2.

With 16 slots, ther eis nothing much you can do. Since there are just 4-gb dimms you will not have interleaving for that, nor for 1 of the 4-256 sets, and 2-way for the other 2 4-256.

People smarter than use might be able to use, or avoid, the 2 way interleave, for example by using a GH section which will land on a predictable set of physical memory, but if it's that critical, then somehow getting an other set of 4-1GB would seem the better way to go.

If the system is currently almost happy with 4GB, and really just an additional 2GB will make it very happy, then I would consider to populate 0 and 1 with 4-256, stick the 4-1G in 2, and leave 3 empty for a total of 6GB. Run with that for a week taking some performance indications (collect, 'time' for a job'.
Now add 4-256 back for 7GB, run for an other week and compare jobs.

So while I would be inclined to also stick the 4-1GB in 0, to do the above #2 might be handier. It matters little.

Do be sure to issue >>> SHOW MEMORY for every config. Both now, and after adding.

Enjoy!
Hein.
MrEdu
Occasional Advisor

Re: ES45 1B Memory Question

First let me say thank you to everyone who replied.

Here is what we ended up doing.

We removed the last bank of 4 x 256MB DIMMs and replaced with 4 x 1GB DIMMS.

The additional memory has helped and as of yet have noticed no real negatives. If something comes up I will update.

Once again thanks to everyone!