Power Savings In A Lab Environment

The green lab -- that doesn't cost an arm and a tail and doesn't bark either

Recently after having a discussion with my manager about the cost of a hypothetical 30 person computer lab with both SPARC and X86 technologies we pondered prices and performance.

Here at Sun one can find Sun Ray's in use for workstations everywhere. These workstations have been served off Sun Fire V880's and Sun Fire T2000's quite often in my campus. These systems serve people working on StarOffice, Firefox, Sun Studio, and even Windows applications.

This got me to thinking about the applications I used at my university when I was an undergraduate: ArcGIS, OpenOffice, Mathematica, Matlab, AMPL, SAS, and NetBeans. These all of course run on Solaris SPARC fine, but some other majors relied on Windows only apps too, like MineSight, and SolidWorks.

The buzz-word often heard today, but certainly true from a cost perspective is green technology. A 30 person computer lab doesn't sound like a large lab by today's standards. However, with a 500 watt power supply and a 100 watt monitor per seat, a 30 person lab could potentially use up to 18,000 watts! Luckily most people don't purchase 100+ watt CRT's anymore and power supplies rarely draw their maximum for very long.

Enter the Sun Ray

Still, a power supply capable of drawing 500 watts even running at 50% load (a reasonable industry assumption). Is drawing a lot of power once compounded over a significant number of systems. The Sun Ray, however, only draws 26 watts maximum and typically only 12. Even with the built-in 17" LCD, a Sun Ray 270 has a 60 watts maximum power draw! So, clearly one can quickly compound significant power savings through a lab of Sun Rays. But what about the servers driving the Sun Rays?

A lab of workstations doesn't typically need a backing server - though many still have one for home directories, software licensing, or to provide a more easily managed central software library. Sun Rays being thin clients, however, do need a backing server. But, this makes a systems administrator's job easier! For a simple business lab - with word processing, web browsing and the occasional marketing photo touch-up being the standard use cases - a single Sun CoolThreads server .e.g. the Sun SPARC Enterprise T5220) server would more than suffice for 30 users. For example, the machine can hold up to 64 GB of RAM, and has 4 gigabit ethernet ports which one can trunk to provide a terrific network capability out of the box, or of course, one can add 10 gigabit cards and Fibre Channel cards, if 4Gb/s and 1TB of internal disk is not enough.

But what about the power consumption of this 2U, 64 thread, mean serving machine? A minimum configuration typically idles at only 252 watts and if you can manage to maximally stress the machine, when fully loaded, it will eat 795 watts. About as much as three traditional desktops - you don't need now.

So how do the numbers stack?

One can see the traditional lab using small single-socket machines eats more than 3 times the power of a lab of SunRay's:

Listing of power usage for a SunRay based lab

1: Using an average of peak and idle for each machine.
2: Using 50% of worst case sustained of 1603 watts.
SunFire T5220795494/795212891
SunFire X4600340088121881
SunFire X45001800100011000
SunRay 270601230360
Total 3530
Listing of power usage for a conventional lab

1: Using 50% of the rated 530 watt maximum
The SunFire X4600 is not included here as the desktops can provide X86 based computational power. (It also helps show how much power a conventional lab uses simply on its own.)
SunFire T5220795494/7952774
SunFire X45001800100011000
19" LCD373330990
Ultra 245302651307950
Total 10714

What's this mean to me?

After a quick read of this entry from my manager, he said, "Cool." But, he asked what's a savings 7,184 watts really mean? Well, according to the US Department of Energy's Electric Power Annual the average commercial power cost for 2006 was 9.46 cents per kilowatt. So, for a 30 person lab using the above SunRay setup, versus a traditional desktop setup, one would save $5,937.04 - on average a year, in power consumption alone - not to mention air conditioning costs too.

What about an entire college campus?

If one replaces a number of their lab computers, say across an entire university campus, one could save in power alone $80,000 after about 400 machines. If one needs to add staff, a savings of $80,000 can pay for a well paid staff member quickly! This calculation doesn't even account for cooling savings, and labor savings - which at most company all come out of "operating expense" budgets in direct competition with staff funding.

However, other very nifty uses for SunRay's abound across a large deployment. They are capable not only as desktops, in a lab, but also for information kiosks, and timed access web browsing and e-mail kiosks. Similarly, they can easily be used as corporate, or student low cost, virus immune, home PC's. The user keeps their same desktop and applications open on any device they use -- whether at home, work or a network connected coffee shop. They never have to "shut down", and they can even use VPN technologies to work from off campus. There are various manufacturers who make tablet SunRay's and ruggedized SunRay's, as well as VPN capable SunRay laptops. A college campus can deploy these in numerous uses to help ensure faculty and students have substantial benefit from technology. The ruggedized models would work very well in chemical laboratories for data acquisition and data look-up. While with their low-price and data security (nothing is stored on the SunRay) they can provide off campus access methods for site-licensed software and library resources -- to be checked out the same as a book.

What kind of system characteristics are best for a SunRay server?

SunRay's are a neat device in that it allows an IT group to ensure the demand on their servers is more stable than the occasional job by the occasional user; increasing their return in buying such centralized and large equipment. However, an IT group needs to ensure that they provision a server which meets the SunRay's needs. SunRay's require a server efficient at dealing with a highly multi-threaded workflow. (As there are many users all running multiple applications thanks to standard Unix conventions - none of the Microsoft Windows one window paradigm seen so often elsewhere.) Sun produces their CoolThreads line of servers which are perfect for this paradigm. The newly released Sun SPARC Enterprise T5140, for example, in 1U can have 128 threads -- for the starting price of 7 mid-range, traditional desktops! Imagine the power of a lab of 64, dual processor or dual core workstations, but with the power and administrative savings of SunRay. One could provision for a class to run Linux applications and the immediate next class run Solaris applications, with no administrator overhead, or work on the part of the students either. Similarly, the lab could be locally used by classes through the day and the lab's back-end servers provisioned to be added to the campus' HPC cluster at night. SunRays provide a flat administrative curve for administrator time, compared to the traditional linear curve of Unix workstations, both of which well improve on the more exponential administrative needs of a personal computer model.

SunRay's allow for administrators to simplify their jobs and provide more computing resources to their users, all at a significant cost savings, from hardware and labor to simple power consumption.


The line with the 5220 doesn't make sense:
quantity 2, min/max 494/795 total 774

should be 494\*2=988
or 795\*2=1590

Otherwise nice senario

Posted by Rob McDonald on April 17, 2008 at 01:22 PM MDT #

Hi Rob,
Thank you for pointing out my bizarre number choice there.

Posted by Clay on April 17, 2008 at 01:33 PM MDT #

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