Ram slot popolated scenario + power consumtion c6100

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korban

Member
Feb 12, 2013
33
1
8
Belgium
www.befr.ebay.be
Hi all,

I have made a test who surprised me with his impact.

I actualy have 2 C6100 with all node @ 24Gb (12 x 2Gb).

I recently buy 4 x 16Gb and I have replaced the 12 x 2 by 4 x 16 for an extra amount of 40Gb of ram.

When I compare the two configuration with a wattmeter at the wall plug and the server in IDLE state… I have a delta of 30w !

It is more than expected, because I don’t upgrade the ram to save power.

If I do a good calculation

0.03 KW/h x 24h x 365d = 262.8 KW/h/Y

262.8 x 0.218 (Power cost a lot in Belgium) = 57.29 $/Y

It could be interesting to know when we need to buy extra memory, feg 4 x 16 vs 8 x 8.


8 x 8 = 450$ http://www.newegg.com/Product/Product.aspx?Item=N82E16820239420
4 x 16 = 520$ http://www.newegg.com/Product/Product.aspx?Item=N82E16820239276
Delta 70$

Evalued power consumtion / module = 3,75 W
8 x 8 = 30W
4 x 16 = 15W
Delta 15W
29$/Y

Delta financial amortization 2 Y 5M (29 month)

It stupid but I always bought for minimum 3 year and I keep on the and more slots for extention
 
Last edited:

OBasel

Active Member
Dec 28, 2010
494
62
28
Great info. Helped me with my decision (went with 8gb dimms) on another system
 

azev

Well-Known Member
Jan 18, 2013
768
251
63
Hi Korban, what cpu do you run on your C6100 blades ? I was about to get one and are looking to get more ram for them. I heard from another forum member that the common L5520 CPU that came with the system does not support 16GB modules. Do you mind sharing which module are you using on your systems ?
 

Patrick

Administrator
Staff member
Dec 21, 2010
12,511
5,792
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Hi Korban, what cpu do you run on your C6100 blades ? I was about to get one and are looking to get more ram for them. I heard from another forum member that the common L5520 CPU that came with the system does not support 16GB modules. Do you mind sharing which module are you using on your systems ?
Xeon 5500 series CPUs maxed out at 8GB RDIMMs
 

korban

Member
Feb 12, 2013
33
1
8
Belgium
www.befr.ebay.be
Hi Korban, what cpu do you run on your C6100 blades ? I was about to get one and are looking to get more ram for them. I heard from another forum member that the common L5520 CPU that came with the system does not support 16GB modules. Do you mind sharing which module are you using on your systems ?
Hi azev, I have L5520 in mine c6100 and they are running fine with 16gb ram module but the speed is limited to 1066. Check the spec @ page 2 http://www.dell.com/downloads/global/products/pedge/en/poweredge-c6100-spec-sheet-en.pdf
But 1066 looks to be the max speed of L5520 even the server supports 1333.

I reached 64gb without any problems with 4 modules, but I don't know if you can go to 192/node with the L5520.

On intel site they said max 144gb with ARK | Intel® Xeon® Processor L5520 (8M Cache, 2.26 GHz, 5.86 GT/s Intel® QPI)

Take care the server will only accept 1 or 4 or 6 or 12 ram modules per node. Check the dell c6100 owner manual @ page 93

I have buy this 4x16 kit KVR16R11D4K4/64 http://www.kingston.com/dataSheets/KVR16R11D4K4_64.pdf

Hope it help :)
 

mrkrad

Well-Known Member
Oct 13, 2012
1,244
52
48
you know that full interleaving (3x2 or 3x3) is a configurable option on tylersburg. The loss from using all dimm slots and slowing down in speed is offset some by interleaving the 3 x2 or 3 x3 channels so that reads/write can occur more per clock cycles.

Imagine ssd's they interleave data so 9 chips could contain data from all sectors so a read could call upon 9 chips at once. If not you could arrange 3 banks but at most a sector is landed on of the three banks, thus limited read/write speeds to 3 chips.

This eats power.

Dropping the speed (1333->1066, 1066->800) saves power. the 25% drop from 1333-> 800 saves a ton of power but chokes your processor if it wants to talk at 1333. If its a 800 or 1066 processor, the drop to 800 doesn't matter.

Using 4 dimms in a triple channel setup could reduce throughput (and power greatly). What happens is the 4th dimm gets mapped to the 1st channels, but at 33% of the speed of the other bank of 3.

ESXi can be told to use lower ram first - in theory this 33% handicapped single dimm would be in high ram. For this processor, you could expect a single channel of dimm to render the cpu down to the speed of the core2 (x5450). The gain (other than power) from core2 to nehalem/westmere is all in the memory controller.

Handicapping the memory speed can make a single socket CORE2 xeon just as fast as a nehalem , if not faster.