Wattage of 16 8GB DDR2 ram sticks

Zepher

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I tried to google and search here but didn't find what I was looking for.

I have a Dell T7400 workstation that has 2x Xeons and 128GB of Ram,
it has 16 8GB sticks in it, Samsung 16pcs 8GB 2RX4 PC2-5300F DDR2-667 ECC Fully Buffered FB-DIMM Memory RAM

The machine is going to be in an environment that doesn't require that amount of Ram, it could have 8GB of ram and be fine.
I just want to know if having all of those sticks installed draws a significant amount of power and if it does, approx how much.
 

Zepher

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if it's only about 32watts, then that isn't bad at all.
 

[Ion]

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Echo I'd disagree with that. Regular RAM I'd believe might be 2W per stick, but FB-DDR2 runs very hot and draws comparatively more power. This suggests 5 to 20W per DIMM, which is admittedly a very broad range, but might be in the right ballpark.
 

cyclone3d

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If you look up the spec sheet for the actual chips used on the RAM sticks, I would think that that would list the rated power draw. Then a bit of quick multiplication and you should have a close answer.
 

Zepher

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if it's 20 watts, that's about 320 watts for all 16 sticks, pretty hefty draw.
I bought this machine recently and never messed with the insides. It has these riser cards with 8 sticks on each. It looks like the riser cards are plugged into 2 of the dimm slots on the board.
The machine at idle draws 440 watts from the wall according to the UPS display.
 

daglesj

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My T5400 with dual quad 3.3GHz Xeons and 8x2GB DDR2 ECC ram idles at 230W and pulls around 400W at full pelt! I just dumped it due to the heat and running costs. Most of the heat was the RAM. That ECC DDR2 is a eco dinosaur.

My new 16GB DDR4 5820K build sits at 65W idle.
 
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Zepher

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I pulled out 96GB of ram and the riser cards and it now idles at 190-210 watts.
My new dual E5-2670 with 128GB DDR3 and 6 green drives idles around 220 watts
 

daglesj

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Yeah I equate these type of machines to late 1960's muscle cars. Great in a straight line but expensive to run and they don't do corners.
 

flatty

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I was shocked when I tried to find an answer or at least a clue for you using this:
OuterVision Power Supply Calculator

Unfortunately is not having the 8GB DDR2 option, but to try an extrapolation, for 16x2GB required 194W, for 16x4GB required 292W... so, I wont wonder for 450W for 16x8GB. Now, thinking that probably isn't an accurate calculation (because im pretty sure they take in consideration an absolute covering amount and also have the interest to "inflate" the PSU size) I assume that anyway the answer is in the range 300-400W
 

Blue Fox

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I was shocked when I tried to find an answer or at least a clue for you using this:
OuterVision Power Supply Calculator

Unfortunately is not having the 8GB DDR2 option, but to try an extrapolation, for 16x2GB required 194W, for 16x4GB required 292W... so, I wont wonder for 450W for 16x8GB. Now, thinking that probably isn't an accurate calculation (because im pretty sure they take in consideration an absolute covering amount and also have the interest to "inflate" the PSU size) I assume that anyway the answer is in the range 300-400W
PSU calculators often aren't all that accurate. FB-DIMMs are also in a class of their own in terms of power consumption. Heatsinks and active cooling were required.
 

flatty

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no matter how accurate is, the order of measure cant be wrong, I didn't expect a hundred of Watts consume.
 

daglesj

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Whichever way you look at it running large amounts of super hot ECC DDR2 just isn't worth it long term.

If you need the heat then just buy an electric fan heater.
 

WhoBeDaPlaya

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FB-DIMMs run insanely warm.
I had a T7400 under my desk at work for a couple of years with 64GB, and don't miss it in the slightest o_O
 

pxc

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Originally, the AMB on each FB-DIMM used around 5W. There have been lower power AMB (sometimes called AMB+) chips around for several years, and those use ~3W each.

The power range for DDR2 FB-DIMMs varies widely, since there are older memory sticks using the older AMB and 1.8v memory, then at the other extreme are FB-DIMMs using low power AMB and 1.55v memory.

The datasheet for OP's DIMMs shows it's 1.8v memory and low power AMB. Power consumption in the active state seems to be pretty bad, ~14W max @ 1.9v DRAM/1.55v AMB. At nominal/rated voltages, that's probably closer to 12W per FB-DIMM when in an active state. At idle, it's ~3-4W per FB-DIMM.
 

Zepher

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it wasn't all Samsung dimms. When we pulled them out, half were another brand. I can't recall what brand off-hand but they are sitting on my desk upstairs.
 

ChRoNo16

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its the cpus that use the most in that thing.... mine runs sub 330~ watts, or it did until i got rid of it.
 
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