Power Costs - Upgrade Worth It?

[timothy.lazarus]

I've read the stickied thread at the top, which really helped. I've also read other posts that suggested that the socket made a big difference in terms of motherboard power consumption and that moving from 1366 to 2011 can help a lot. With both of these in mind, I need some help on deciding between sticking with my current setup until the Xeon-D systems (especially DDR4) come down in cost or doing an interim upgrade.

Current Systems: 2 x DL380 G7 - One with dual X5660s, One with dual E5620s. 128GB RAM in each, 128GB SSD in each for vFlash Read Cache connected to P410i (all other storage is via iSCSI from my TS140), single ConnectX-3 card in each

The X5660 DL380 uses about 160Watts, largely at idle - it is only running the vCenter Appliance right now
The E5620 DL380 idles at about 140Watts, no VM's running.

I'm spending about $50 a month in ESXi server power costs alone, plus additional as yet undetermined power costs for my 10GbE switch and TS140 ZFS storage server. I'm also considering adding a 3rd server for VSAN testing. So, are any of the choices below worth it?*

- switch all CPUs to L5640s - relatively cheap on eBay right now.
- switch to Avoton/Rangeley C2758 servers - huge hit in processing power, but huge reduction in power usage. Roughly $600/server, ASSUMING I can use my existing DDR3 memory in the new systems (5018A-MHN4). I'm not very dependent on CPU, given that I tend to spin things up and down a lot as I test infrastructure options but not run anything for a long period of time.

* Without including the value associated with fun new toys to play with

 

[timothy.lazarus]

Okay, after reading the thread below, I may upgrade one of my servers to L5460s to see how the idle power usage compares, but it sounds like moving to E5 servers isn't necessarily a big win. The C2758 servers are still interesting, but not for ESXi. I'll probably wait until DDR4 is less than $1000/128GB new.

How much power savings moving from Xeon x5600 to E5

 

[Rand__]

So lets run the calculation
300 Watts @idle, lets say 600 Watts at load and 4h/day@ load -> (20*300 + 4*600 = 350w/h)

Now lets assume you can get that to 100W@idle and 300W@load (depending on required max CPU capability) -> (20*100 + 4*300 = 133w/h)
In Europe i usually calculate €2.5 per W per Year so thats (350-133=) 217w/h savings =>
Your budget would be €540/year which makes it worthwhile.

Adjust appropriately to your specific parameters

 

[timothy.lazarus]

Thanks Rand_. Using your calculations, I get $720/year in electrical costs now, and $272 with the reduced numbers you list in your thread. We pay 0.08179 * x kWh plus an obscene amount of suspicious charges for delivery and other things that are also based on the usage... Although you live in Europe, so I assume it is worse

So if I bought 2 C2758 servers, it would be worth it in 2 years. The ROI on Xeon-D is still a lot farther out, since they cost 3 times as much with the new memory. I'm also still curious about the power usage if I move to L5640s.

Thanks for your help!