Cooler Servers or Cooler Rooms?

mstansberry writes "Analysts, experts and engineers rumble over which is more important in curbing server heat issues; cooler rooms or cooler servers. And who will be the first vendor to bring water back into the data center?"

Comments

Why not both?

[tquinlan]

Unless you make things so cold as to prevent things from working properly, why not just do both?

Re:Why not both?

[Anonymous Coward]

Cost.

The question isn't whether it's good to keep both cool. The question is, which makes more financial sense? Cooling the whole room? Spending the money to purchase servers with a low heat-to-computation ratio?

Probably a combination. But to say that people should equip every computer with VIA ultra-low-power chips _and_ freeze the server room is silly.

Re:Why not both?

[elgatozorbas]

The question isn't whether it's good to keep both cool. The question is, which makes more financial sense? Cooling the whole room? Spending the money to purchase servers with a low heat-to-computation ratio?

In that case, I would say: cool the room. The room is forever (on this timescale), the servers maybe change every 5 years. Of course, start by NOT choosing the hottest server too, but I would invest in the room.
Also I don't expect room cooling techniques to improve significantly in the next few years. Servers hopefully will.

Re:Why not both?

[Anonymous Luddite]

>> I would say: cool the room.

I think you're right. That's the way we do it, but - (there's always a but) some cabinets still get damn hot depending on what's in the rack. Sometimes you need to do spot cooling as well, or put in bigger fans to keep the equipment closer to ambient.

I think starting with a cool room is the most cost effective way though - not to mention it makes work "O.K." in August...

Re:Why not both?

[FireFury03]

The question isn't whether it's good to keep both cool. The question is, which makes more financial sense? Cooling the whole room? Spending the money to purchase servers with a low heat-to-computation ratio?

You don't need to cool the whole room - you could just cool the cabinets. Most cabinets have doors and sides, an open bottom and fans at the top. So you can blow cold air up the inside of the datacabinet (which is what most datacentres do anyway) and take the air from the top to recycle it with reasonably minimal air (and hence heat) exchange with the rest of the room.

well I've always wondered this

[Saven Marek]

I've always wondered this. why have duplication of a function in a server across every single server box when it could all be done in the environment. For example all servers get electricity from the server room and all servers get network from the server room so why not all servers get cooling from 10F cooling in the server room.

It makes sense!

Re:well I've always wondered this

[T-Ranger]

What I have never understood is why servers virtually always have AC power supplies. Yes, you can get NEBS(?) compliant servers that take DC, but this isnt really a general option, but a distinct model line compleatly.

UPSs take AC, turn it to DC, charge their batteries. A sepearate system takes DC from batteries, inverts it and sends out AC. (Good UPSs, anyway. Otherwise they are "battery backups", not uninteruptable) Computer power supplies take AC and distribute DC inside the case. WTF?

Why doesn't APC start selling ATX power supplies? Directly swap out AC powersupplies, have them plug into the DC providing UPS and/or per-rack (or even per-room) powersupplies.

Electrical codes are a BS excuse. Even if you needed verdor specific racks, a DC providing rack is, so far as the fire marshal should be concerned, just a very large blade enclosure, which are clearly acceptable.

I cant beleive that Im the first one to ever come up with this idea. So there must be some problem with it.... Some EE want to explain why this wouldnt work?

Re:well I've always wondered this

[warpSpeed]

if your single AC to DC converter failed everything would go down

Assuming that you only have one converter. The nice thing about AC to DC conversion is you can have multiple AC converters all feeding the same DC voltage to a single set of conductors to run the DC power out to the machines. The converters can even be out of phase. If the power conversion system is designed right, any one or two converters can fail, be disconnected from the power feed, and the remaining good converters will pick up the slack.

Err, well, both?

[Pants75]

The servers are the heat source and the cool room air it the cooling mechanism? Yes?

So take your pick. To make the servers cooler, either buy new more efficient servers or buy a whacking great air con unit.

Since the servers are the things that actually do the work, I'd just get feck off servers and a feck off air-con unit to keep it all happy!

Everyones a winner!

If you have cooler servers...

[havaloc]

...you won't need as much cooling in the room. Easy enough. This will save a ton of money in the long run, not to mention the environment and all that.

First thing..

[Anti Frozt]

That comes to mind is that it will probably be vastly cheaper to cool a rackmount specifically than to lower the ambient temperature of an entire room to the point that it has the same effect. However, I'm not entirely sure how well this scales to large server farms and multiple rackmounts.

I think the best option would be to look at having the hardware produce less heat in the first place. This would definitely simplify the rumbling these engineers are engaged in.

Re:Outside air?

[green pizza]

Maybe my ignorance is showing here, but does any installation use outside air for cooling? It seems that it would make sense in places that have cold winters (like here in the midwest).
You'd need a lot of filtering and/or humidity control to make that a realistic option. Better yet to make use of outside air temperature. Which is exactly what your heatpump loop or your AC cooling tower is for.

Cooler servers...

[Aphrika]

From experience of aircon failing/breaking.

At least if a server fails it's one unit that'll either get hot or shutdown which means a high degree of business continuity.

When your aircon goes down you're in a whole world or hurt. Ours went in a powercut, yet the servers stayed on because of the UPSes - hence the room temperature rose and the alarms went off. Nothing damaged, but it made us realise that it's important to have both, otherwise your redundancy and failover plans expand into the world of facilities and operations, rather than staying within the IT realm.

Re:Ma Bell has been doing this for years

[jhines]

Telecom equipment runs off -48VDC, and the phone company uses big batteries as their UPS.

It exists, it just is expensive.

Re:Why not neither? Remove the power supplies.

[Critical Facilities]

UPS's do not run exclusively off of DC. You are correct that they convert AC to DC, then route it through the battery strings, then invert it back to AC current. While this does generate some heat, it is NOTHING compared to the server racks. I've worked in datacenter environments for several years now, and I can say that one of the biggest foes to efficient cooling is poor space planning.

I've never seen people so difficult to communicate with as hardware planning people. You would be amazed at how much better a computer room gets cooled when the computer equipment gets installed properly in a "hot aisle/cold aisle" configuration. Also, vendors and hardware folks don't like to have things pointed out that they're not doing, like making sure not to install a top discharge cabinet on the edge of a cold aisle right next to a front intake cabinet, or installing plenums inside the cabinets as some vendors recommend.

A combination of good space/hardware planning as well as honesty and communication in determining potential heat loads are probably the 2 biggest factors in keeping a computer space cold, IMHO. No one's being helped by just guessing as what a rack full of SunFire servers is going to put out in terms of heat, find out from the manufacturer. And don't feel that your engineering staff is trying to tell you how to do your job or piss you off by letting you know that a rack you've installed is disrupting airflow. We're all in this together, remember?