HP xw9300 memory upgrade

I would like to upgrade the memory in my HP xw9300 workstation (dual Opteron
280 cpu's) and have a couple of basic questions about this.

1. According to the hardware specs, the system uses DDR SDRAM ECC
registered memory (DDR PC3200, CL=3, registered, ECC, DDR400, 2.6V, 184-pin
DIMM). Will any PC3200 memory module (i.e. any brand and part number) that
meets these specs work? Although it seems like it should, I've noticed that
memory retailers, like Crucial for example, have different part numbers for
what appears to be identical memory (the only difference that I can see is
the computer it goes in). This makes me wonder if there's some additional
criteria involved that I should be aware of.

2. In this computer there are 8 memory banks divided into two groups of four
(one group for each cpu). The manual says the memory must be added in
matched pairs, and I've noticed with dual processor setups that it's always
matched between cpu groups as well. Is that a requirement though? That is,
if I upgrade the memory will I actually have to add *four* sticks to the
system (a matched pair to each group)?

Thanks for any feedback on these. I appreciate it.

-Pat

* Pat Kelecy:

> I would like to upgrade the memory in my HP xw9300 workstation (dual Opteron
> 280 cpu's) and have a couple of basic questions about this.
>
> 1. According to the hardware specs, the system uses DDR SDRAM ECC
> registered memory (DDR PC3200, CL=3, registered, ECC, DDR400, 2.6V, 184-pin
> DIMM).

Almost right. The xw9300 can use either DDR333 or DDR400 (You're limited
to DDR333 when going over 16GB and up to 32GB on this machine).

> Will any PC3200 memory module (i.e. any brand and part number) that
> meets these specs work?

Yes.

> Although it seems like it should, I've noticed that
> memory retailers, like Crucial for example, have different part numbers for
> what appears to be identical memory (the only difference that I can see is
> the computer it goes in). This makes me wonder if there's some additional
> criteria involved that I should be aware of.

No, at least not in case of the xw9300.

> 2. In this computer there are 8 memory banks divided into two groups of four
> (one group for each cpu). The manual says the memory must be added in
> matched pairs, and I've noticed with dual processor setups that it's always
> matched between cpu groups as well. Is that a requirement though? That is,
> if I upgrade the memory will I actually have to add *four* sticks to the
> system (a matched pair to each group)?

Nope, you don't have to. The memory configuration "requirement" by HP is
just nonsense. You can distribute the memory (almost) as you want, i.e.
4GB on CPU1 and nothing on CPU2, or i.e. 2GB on CPU1 and 8GB on CPU2
etc. Note that the xw9300 is not a shared memory platform but uses NUMA
technology, every processor has it's own dedicated memory controller and
memory. There is no need for both processors having identical memory
setups, and there also is no need for both CPUs to have memory at all
(it's enough if one processor has some memory). The CPU without RAM will
just use the memory of the other processor.

However, one of the advantages of having equal memory on both processors
is that you can activate memory interleaving. One problem with NUMA is
that memory latency varies a lot depending if the task needs data from
locally connected memory (fast) or from memory connected to another CPU
(remote memory, slower). Memory interleaving distributes data equally
between local and remote memory, resulting in almost constant memory
latency times. Without interleaving, the latencies are very variable.

Benjamin, still having his old xw9300 sitting around

"Benjamin Gawert" <> wrote in message
news:...
>* Pat Kelecy:
>
>> I would like to upgrade the memory in my HP xw9300 workstation (dual
>> Opteron 280 cpu's) and have a couple of basic questions about this.
>>
>> 1. According to the hardware specs, the system uses DDR SDRAM ECC
>> registered memory (DDR PC3200, CL=3, registered, ECC, DDR400, 2.6V,
>> 184-pin DIMM).
>
> Almost right. The xw9300 can use either DDR333 or DDR400 (You're limited
> to DDR333 when going over 16GB and up to 32GB on this machine).
>
>> Will any PC3200 memory module (i.e. any brand and part number) that
>> meets these specs work?
>
> Yes.
>
>> Although it seems like it should, I've noticed that memory retailers,
>> like Crucial for example, have different part numbers for what appears to
>> be identical memory (the only difference that I can see is the computer
>> it goes in). This makes me wonder if there's some additional criteria
>> involved that I should be aware of.
>
> No, at least not in case of the xw9300.
>
>> 2. In this computer there are 8 memory banks divided into two groups of
>> four (one group for each cpu). The manual says the memory must be added
>> in matched pairs, and I've noticed with dual processor setups that it's
>> always matched between cpu groups as well. Is that a requirement though?
>> That is, if I upgrade the memory will I actually have to add *four*
>> sticks to the system (a matched pair to each group)?
>
> Nope, you don't have to. The memory configuration "requirement" by HP is
> just nonsense. You can distribute the memory (almost) as you want, i.e.
> 4GB on CPU1 and nothing on CPU2, or i.e. 2GB on CPU1 and 8GB on CPU2 etc.
> Note that the xw9300 is not a shared memory platform but uses NUMA
> technology, every processor has it's own dedicated memory controller and
> memory. There is no need for both processors having identical memory
> setups, and there also is no need for both CPUs to have memory at all
> (it's enough if one processor has some memory). The CPU without RAM will
> just use the memory of the other processor.
>
> However, one of the advantages of having equal memory on both processors
> is that you can activate memory interleaving. One problem with NUMA is
> that memory latency varies a lot depending if the task needs data from
> locally connected memory (fast) or from memory connected to another CPU
> (remote memory, slower). Memory interleaving distributes data equally
> between local and remote memory, resulting in almost constant memory
> latency times. Without interleaving, the latencies are very variable.
>
> Benjamin, still having his old xw9300 sitting around
>

Thanks Benjamin for the information! Just what I was looking for.

I have a couple of follow on questions for you. I hope that's ok.

1. I noticed that HP sells a 2GB DIMM cooling duct kit for the xw9300. If I
want to use 2GB DIMMs do I need to add this kit also? I'm would like to add
4GB to the system and would rather do that using two 2GB modules than four
of the1GB modules.

2. Are there any particular brands of memory you would recommend for
this(e.g. Samsung, Micron, Hynix, Infineion, Crucial, Kingston, etc)? I'll
probably buy off of eBay to save some money, but have noticed quite a price
range between different brands of memory for identically spec'd modules.
I'm guessing there's some reason for this though, and would like to get
something that's good quality.

Thanks again for the help. -Pat

* Pat Kelecy:

> Thanks Benjamin for the information! Just what I was looking for.
>
> I have a couple of follow on questions for you. I hope that's ok.

Sure, that's what this group is for.

> 1. I noticed that HP sells a 2GB DIMM cooling duct kit for the xw9300. If I
> want to use 2GB DIMMs do I need to add this kit also?

What revision of the xw9300 do you have (old or newer one; older one has
square heatsinks with fan on top while the new version has tower
heatsinks with side-mounted fan)? If you have the old version then yes,
you definitely want the additional memory cooling duct. The new version
has a combined CPU/memory cooling duct already so it's not necessary
there...

> I'm would like to add
> 4GB to the system and would rather do that using two 2GB modules than four
> of the1GB modules.

That's no problem.

> 2. Are there any particular brands of memory you would recommend for
> this(e.g. Samsung, Micron, Hynix, Infineion, Crucial, Kingston, etc)? I'll
> probably buy off of eBay to save some money, but have noticed quite a price
> range between different brands of memory for identically spec'd modules.
> I'm guessing there's some reason for this though, and would like to get
> something that's good quality.

Basically, all of these brands should be fine (but I'd not recommend
Infineon as this name has been abused a lot in the past), as long as the
modules conform to the specification. I'd recommend getting modules from
Kingston or Crucial/Micron (or any other brand name that has
compatibility lists for their memory) that are guranteed to be
compatible with the xw9300.

Benjamin

"Benjamin Gawert" <> wrote in message
news:...
>* Pat Kelecy:
>
>> Thanks Benjamin for the information! Just what I was looking for.
>>
>> I have a couple of follow on questions for you. I hope that's ok.
>
> Sure, that's what this group is for.
>
>> 1. I noticed that HP sells a 2GB DIMM cooling duct kit for the xw9300.
>> If I want to use 2GB DIMMs do I need to add this kit also?
>
> What revision of the xw9300 do you have (old or newer one; older one has
> square heatsinks with fan on top while the new version has tower heatsinks
> with side-mounted fan)? If you have the old version then yes, you
> definitely want the additional memory cooling duct. The new version has a
> combined CPU/memory cooling duct already so it's not necessary there...

Thanks for this info. I checked and I have the old version (each cpu is
covered by a square, finned heat sink with a fan on top, and there's a blue
plastic duct covering both). So I guess I'll need the cooling duct for the
memory.


>> I'm would like to add 4GB to the system and would rather do that using
>> two 2GB modules than four of the1GB modules.
>
> That's no problem.
>
>> 2. Are there any particular brands of memory you would recommend for
>> this(e.g. Samsung, Micron, Hynix, Infineion, Crucial, Kingston, etc)?
>> I'll probably buy off of eBay to save some money, but have noticed quite
>> a price range between different brands of memory for identically spec'd
>> modules. I'm guessing there's some reason for this though, and would like
>> to get something that's good quality.
>
> Basically, all of these brands should be fine (but I'd not recommend
> Infineon as this name has been abused a lot in the past), as long as the
> modules conform to the specification. I'd recommend getting modules from
> Kingston or Crucial/Micron (or any other brand name that has compatibility
> lists for their memory) that are guranteed to be compatible with the
> xw9300.

Thanks again. I appreciate the help. -Pat