IBM x3650 M3 Server, what is optimal RAM config?

[BigTom209]

Our IT department currently has one of these x3650 M3 servers running a archive historian program for the company and we're trying to find out ways to improve performance accessing the archives. The vendor said increasing the amount of RAM would help as the archive files are loaded into the RAM and therefore once they've been loaded the next user who tries to access that time frame of data it will transfer very quickly.

So I started looking into the server and found out it has only 16gig of RAM, (4) 4gig sticks populated in channels 3,6,12 and 15... the sticks are mismatched also 3/4 are HP and one is Samsung (although have same specs) looking at the IBM overview basically it seems the IT department is only using 2 of the 3 available channels for the CPU so one performance increase would even be just getting another set of RAM sticks for channels 9 and 18. But I want to take it one step further, and increase our RAM quite alot which is why I'm here asking this question.

What would be the optimum in performance in terms of RAM configs for this server?

Is there any perks to using quad rank over dual? I know I max out at 192GB of quad rank vs 288GB of dual rank... but I don't think I'll have that much RAM installed so basically the question would be does the quad perform better?

Also, is it better to have just a single large RAM module per channel or (3) smaller RAM modules? I thought I read in the manual if using (3) modules your channel speed maxes out at 800MHZ where as if you use a single module you can run 1333MHZ. If we're looking for performance you'd think running a single module would therefore be faster...?

Does the voltage of the module really matter? All the IBM listed supported 16gig modules are 1.35V where as I can get 8gig at 1.5V. They are both PC3L-10600 but just different voltage.


Articles I've been reading

http://www-03.ibm.com/systems/info/x86servers/serverproven/compat/us/xseries/upgrades/mmatrix.html

http://www-947.ibm.com/support/entry/portal/docdisplay?lndocid=MIGR-5083595&brandind=5000008

 

[Tradesman1]

I'm sure other's will jump in, and I know my initial thoughts, but will do a little research and get back, any idea how many users, what type of disk configuration and what type of network connection(s) (all sort of come into play when dealing with servers)

 

[Legohouse]

Hello,

Generally, Single Rank Memory is faster than Dual Rank Memory, in laymen’s terms when a computer accesses Single Rank Memory it only has to go around the track once, where are Dual Rank it would have to go around the track twice. It is the similar for Quad rank. Increasing the number of ranks per DIMM increases memory density in the channel, but does not enhance performance; too many ranks in the channel can cause excess loading and decrease the speed of the channel.

IBM x3650 M3 supports many different configurations depending on size, density, quantity etc so if you plan on keeping your original memory, the first thing to check is what type that is and then make sure you match it. Let me know if it is Registered ECC (RDIMM) or Unbuffered ECC (UDIMM).

Going with the largest RAM size per module is always better than three smaller sized modules. (eg. Single 8GB is better than 2 x 2GB + 1 x 4GB). The maximum memory speed is determined by the combination of the microprocessor, DIMM speed, and the number of DIMMs installed in each channel.

Single module per channel is better in terms performance if you are using 1333MHz memory. But it all depends on the amount of memory you are looking for and the number of processor you have installed.

If you have only one processor then you are most likely to use two or three slot per channel. If you have two processors, you have access to all the 18 slots (12 slot if you are using quad rank memory) and the number of memory per channel can be reduced.

Note: A minimum of one DIMM must be installed for each microprocessor. For example, you must install a minimum of two DIMMs if the server has two microprocessors installed. However, to improve system performance, install a minimum of three DIMMs for each microprocessor.

Your server supports both the voltages and yes, voltage matters. Try matching the voltages if you are trying to use the new memory with the existing memory.

Note: In two-DIMM-per-channel configuration, a server with an Intel Xeon X5600 series microprocessor automatically operates with a maximum memory speed of up to 1333 MHz when one of the following conditions is met:
– Two 1.5 V single-rank or dual-rank RDIMMs are installed in the same channel. In the Setup utility, Memory speed is set to Max performance mode.
– Two 1.35 V single-rank or dual-ranl RDIMMs are installed in the same channel. In the Setup utility, Memory speed is set to Max performance and LV-DIMM power is set to Enhance performance mode. The 1.35 V RDIMMs will function at 1.5 V.

Compatible memory for IBM System x3650 M3:
Registered ECC memory (RDIMM)
Unbuffered ECC memory (UDIMM)

If you need any more info do let me know. Good luck.

 

[BigTom209]

I'm sure other's will jump in, and I know my initial thoughts, but will do a little research and get back, any idea how many users, what type of disk configuration and what type of network connection(s) (all sort of come into play when dealing with servers)

I don't have physical access to the server nor any sortof layout of their network, but I have remote desktop capability and some general knowledge.

Network I believe internal to the servers is GB but the service to alot of the end users depending on location is probably 100MB/s

User count, we have about 200 licensed users who can access the data, most of which are minor users gathering a few points for maybe a day here or there... but others are heavy hitters and can search hundreds of tags for years of data at a 1 second saple rate (ie hundreds of thousands if not millions pieces of data per query) and there are also other vendors programs which access the data to use for calculations.

So a moderate amount of traffic coming from many various sources.

Our hard drive config is a bit goofy as we had to work with some previous installs, but the main archives spanning approx 1 years are located on (4) 15K SAS IBM enterprise grade drives in a RAID10 config, so short of going SSD it's about as good as we can get speed wise. The program/OS are located on a pair of 15K drives in a mirrored raid, and then any old archives are on a set of slower but large 10K mirrored drives

 

[BigTom209]

Legohouse:


Sorry I forgot to mention, currently installed is (4) "4GB 240p PC3-10600 CL9 36c 256x4 DDR3-1333 2Rx4 1.5V ECC RDIMM" so RDIMMs

And personally I don't care to keep the old RAM, 4 gig sticks new are like $30 and again they put in mis-matched brands into the server which just seems silly to me. Maybe being on different channels it doesn't matter but personally I like to see all matching.

Interesting notes about the ranks... I like the laymans terms using the track. I had googled the question and read many pages but my biggest thing is performance since I likely won't be maxing out the available slots I might as well make the best of the few I use, so if as you say single or dual function faster than quad I'd rather install maybe (6) 16 or 8 GB dual rank vs the quad rank. You always assume larger number must mean it's better right?

The server is using 2 processors, and they are Xeon x5600 series

I don't think the IT department will install hundreds of gig into this machine so I'm guessing I can make a case for best performance using 1 module per channel, and since I want a solid increase in RAM it comes down to either (6) 8GB or (6) 16GB sticks... going from 16gig to 48 or 96 is a decent step either way, I'll have to contact the software vendor and see if they can recomend either or, ie will I see more gains with the 96GB of RAM or is 48GB good enough. All depends I guess how their software uses the RAM in the first place.

So based on that, and from what you guys have told me, I need to source IBM x3650 compatible 8 or 16 GB, 1333MHz, single rank prefered or else dual rank RAM, install (1) module per channel, and make sure if 1.35V chips IT runs the setup to run them in enhanced mode bumping them up to 1.5V.


Anything else I should be looking or watching for?

 

[Tradesman1]

Preferable to run run 1.5 sticks, you're not really OCing the DRAM so it's best to keep DRAM within 0.10 of spec voltage, if 1.35 the 1.45

 

[Legohouse]

Legohouse:


Sorry I forgot to mention, currently installed is (4) "4GB 240p PC3-10600 CL9 36c 256x4 DDR3-1333 2Rx4 1.5V ECC RDIMM" so RDIMMs

And personally I don't care to keep the old RAM, 4 gig sticks new are like $30 and again they put in mis-matched brands into the server which just seems silly to me. Maybe being on different channels it doesn't matter but personally I like to see all matching.

Interesting notes about the ranks... I like the laymans terms using the track. I had googled the question and read many pages but my biggest thing is performance since I likely won't be maxing out the available slots I might as well make the best of the few I use, so if as you say single or dual function faster than quad I'd rather install maybe (6) 16 or 8 GB dual rank vs the quad rank. You always assume larger number must mean it's better right?

The server is using 2 processors, and they are Xeon x5600 series

I don't think the IT department will install hundreds of gig into this machine so I'm guessing I can make a case for best performance using 1 module per channel, and since I want a solid increase in RAM it comes down to either (6) 8GB or (6) 16GB sticks... going from 16gig to 48 or 96 is a decent step either way, I'll have to contact the software vendor and see if they can recomend either or, ie will I see more gains with the 96GB of RAM or is 48GB good enough. All depends I guess how their software uses the RAM in the first place.

So based on that, and from what you guys have told me, I need to source IBM x3650 compatible 8 or 16 GB, 1333MHz, single rank prefered or else dual rank RAM, install (1) module per channel, and make sure if 1.35V chips IT runs the setup to run them in enhanced mode bumping them up to 1.5V.


Anything else I should be looking or watching for?

I think you have everything covered. Make sure you refer the manual for any more technical details. Click here -> for "System manual" (Refer from page 104)

As mentioned in the earlier post by Tradesman1, I do recommend the 1.5v memory rather than 1.35v as you are having the Xeon x5600 series processors. Instead of setting the memory to "Enhanced mode" using 1.35v memory rather you could use 1.5v memory and set the memory to "Max performance" mode. (But anyway I think this will work only when you install two or more DIMMs in a Channel).

You might want to check the following link for memory.
8GB Dual Ranked DDR3-1333MHz CL9 RDIMM
16GB Dual Ranked DDR3-1333MHz CL9 RDIMM
You could also try crucial.com or Kingston.com. All these stores have Dual rank 16GB modules and I haven't come across 16GB single rank memory yet and the prices are almost similar. Take your pick.

Good luck with the upgrade. Cheers, mate!!