[ale] [OT]Random wonderings

[JD]

Good questions Tom.

On 04/10/2011 08:20 AM, Tom Freeman wrote:
> 
> I needed to bring a machine back up and recommission it yesterday. A few 
> random thoughts occured to me which I thought I'd toss out. Nothing really 
> commercial, but a DIY might blaze a trail.
> 
> Big thing was, why do we put up with a separate UPS  for a desktop style 
> computer? Although not cheaper, moving the UPS components into the system 
> case could eliminate a cord or two, help with the housekeeping by reducing 
> the exposed "thing" count, and encourage better power for the equipment. 
> Of course, I've never seen such a thing offered commercially, and I'm sure 
> I'm overlooking something important. I do know that thermal management is 
> a potiential headache. Simple overall weight is another. How big those two 
> issues are I just don't know.

Most consumers don't know about UPSes and they certainly don't want to
pay $50 more to have it included. Computer margins are already very
tight on the consumer/low end and a $50 difference would probably be a
deal breaker.

OTOH, UPSes have been included in consumer computers for 20+ years. They
are called "laptops."  For almost every non-gamer, a laptop could make
good sense.

> Of course, there could also be advantages to such a scheme. Aren't some 
> data centers switching to DC power, which is little more than battery 
> power. Such a change might (maybe?) improve the power efficiency just a 
> mite also although the improvement would be pretty minor.

Yes, some data centers are (google) and some have been on DC for many
years - I'm thinking about telecom systems in COs that use batteries for
about 12 hrs of use after power is out, but aren't large enough to have
a staff or automatic generators. Google goes cheap, non-redundant
servers and telecom has redundant everything built into a single system
- very expensive compared to a desktop. I prefer cheap and getting 2
myself, if you need redundancy. If you aren't paying for an OS or
software licenses, then this makes sense. If you are buying those, then
the cost of redundant hardware is almost always cheaper over doubling
the enterprise software license costs.

> Another idea, probably born of ignorance, is why are consumer UPS's setup 
> with just one battery? OK, the UPS can be built for a pretty hefty 
> battery, but still. Why cann't the end user drop in another battery to 
> extend run times? Are the circuits that much different? I am assuming 
> maintaining the same peak current draw here.

The more options you request, the more expensive things become.  For
home, we all want to spend $30-100 for a UPS.  For business, you can
spend $800-$100K easily. I've had to buy (add to my project budget) a
few $120K+ UPSes for some data center expansion. These were connected to
different power substations and served more than just our little 80
server + storage project. I never saw the equipment or even the PO. I
know our project moved forward buying servers, networking, and storage.
Someone here could probably name that UPS company.  I've also specified
lots of APC UPSes over the years from 3K-VA to 30K-VA.  Never had to
spec a generator. ;)

> In fact, are we actually limited to just batteries in our UPS's? Both 
> graphite flywheels and super capacitors appear to have longer lifetimes 
> with similar levels of care as the modern lead acid battery. Plus less 
> hazardous disposal procedures.

Reliability is the main question that came to my mind.  We know how
batteries work pretty well. In tier-4 data centers
https://secure.wikimedia.org/wikipedia/en/wiki/Data_center#Data_center_classification
, batteries are rotated on about a 3 yr cycle (at least where I've
worked).  I've seen rooms and rooms filled with batteries to handle the
time before the turbine generators were brought up.  Battery maintenance
was a pretty big deal at that location. Constant measuring, constantly
adding chemicals (distilled water?) - these were not maintenance free
batteries.

> Last psychotic thought. Is there a nonX-86 derived motherboard out there 
> suitable for desktop/server use? One with the power levels of some of the 
> embeded chips, but with memory expansion and access to the bus and 
> periferal (sp?) boards? I cann't remember such since about 1996 and the 
> Rebel line of servers.

As soon as you leave x86, you've left the mainstream (i.e. cheap) world
and you leave the most common programming compatibility.  You've also
left competition to create highly efficient systems. The only other
options I could see would be MIPS or ARM-based solutions.  ARM is all
around you and there are Debian-based distros that work on it.  I have a
Nokia tablet running Debian here.  Some of the NAS devices run non-x86
hardware, but they provide all the apps you'll ever have with them,
don't they?  Sure, there are home-brew folks hacking on Sigma Designs WD
TV Live systems, but you aren't able to run normal desktop apps on those.

Perhaps you could find an UltraSPARC/T1000/T2000 board (are those still
made?), but it won't be cheap if it is new. The T1000
http://www.sun.com/servers/coolthreads/t1000/ was designed to be a web
server with 8 cores and 32 native threads, but only 1 FPU.  It was a
relative bargain, provided you only needed integer math.  I suspect an
intel Core i5 would provide similar performance these days for much less
effort or cost.  Let me check some overall, general performance stats
....  a Core i5-750 is about 2.3x more compute power than an 8 core
T1000 at 1200Mhz.  I built a desktop Core i5-750 system for about $400 over
2 yrs ago. Obviously, comparing 5+ yr old tech against current CPUs
isn't really fair.  That was a bad idea.

The main issues with these older "enterprise" systems would be power and
noise. About 2-3 yrs ago, power use really dropped across most computing
platforms while performance kept increasing at the same predicted
Moore's Law rates. You can see that from the i5 vs T1000 comparison.
BTW, a current gen T3-2 @ 1.65Ghz is 3.3x more compute power than the
Core i5-750 - but that model is also $8K+ ($9K list).

x86 and ARM are the best bets in my mind.
If you want a UPS built into your PC, get a laptop or a netbook. If you
want lower power, look for a "smartbook."

Sorry that I headed way off track.  Just some thoughts.