Xzin
06-12-2007, 04:59 PM
Dell Datacenter Capacity Planner
http://www.dell.com/content/topics/topic.aspx/global/products/pedge/topics/en/config_calculator?c=us&cs=555&l=en&s=biz
The below figures are for US households only. EU/Asia/Europa/etc will need to convert to your local values, which are most likely different than mine are right now (120v AC mains).
Also, this does not really apply to anybody who is not 5 or more boxing. When you start to stick 5 or more machines together (although at 3 or 4 you start to feel it) you wind up with plenty of heat. In a small room, this can be a problem. Even in a large room, if the room is well enough insulated or you live in a hot part of the world, the heat is produced faster than it can be dissipated.
I came along this nifty tool quite recently although I wish I had come across it sooner. It lists the cooling, heat/power, weight, rack units, airflow and current requirements/output.
If I were to redesign my systems from scratch, I would have bought a rack mount system but given the amazingly ridiculous cost of rack mount cases, I never bothered (we are talking $20 vs up to $200 per case!). That is just dumb. However, racks are specifically designed to allow for cooling and compact power use. So, if you want to 10 box and you don't care what it costs - by rack mounted units.
If you don't want to go that route - you still need to think about cooling and power consumption. 5 computers and other assorted goodies can quickly take up a single 15 amp line. In fact, I will venture to guess that MOST 5 box setups will encounter this problem, especially with older wiring.
A lot of people have absolutely no idea how much power their computers use. Most people don't need to - but it helps to have a general guide as to how much power use you are using. If you want to measure the power consumption at the wall (power supplies are only around 80% efficient, meaning they waste 20% more power in the AC->DC conversion process) then buy something called the Kill-A-Watt. It costs $30 at Thinkgeek and just works. http://www.thinkgeek.com/gadgets/travelpower/7657/
http://www.thinkgeek.com/images/products/zoom/kill_a_watt.jpg
There is a more sophisticated version called Watt's Up Pro for $130 but you don't really need that just to calculate power consumption. http://www.thinkgeek.com/gadgets/travelpower/7acf/
http://www.thinkgeek.com/images/products/zoom/wattsup_pro.jpg
Anyway, your cpu and video card use the most power by far. Modern processors can pull 75 watts easily (this is actually more due to inefficient power supplies). High end video cards can pull up to 200ish watts under full load. Motherboards only use around 10-15, memory 5-10, hard drives 10-20 (more on spin up) and usb peripherals only a few watts. Other add in cards can use more but figure an average modern computer will run you 250 - 300 watts of actual power draw under load. An average 15 amp household outlet will be able to run at 80% capacity over time. If you approach 100% over time, the wires will heat up enough and the breaker will trip. And keep tripping until you stop putting so much load on it. This keeps you from burning your house down. If the breaker were not there, you could overload the lines and cause them to overheat. Heat causes expansion of the connections (loosening them over time) or could outright cause a fire. Be thankful you have breakers.
15 Amps times 120 Volts = 1800 Watts. 80% of that is 1440. So a single 15 amp breaker can safely take 1440 watts continually all day and night, assuming the wire is in perfect condition and no other weirdness is going on (staples through power lines, frayed wires, etc). If each computer uses 300 watts, that is 1500 watts. Just for the computers. That does not count the monitors (17" LCDs figure 20 - 30 watts each) nor the room lights, or anything else you have on the circuit (speakers, tv, etc). MOST residential houses or apartments will only put a single 15 amp line to a single room. Sometimes only a single 15 amp line to two rooms - I have even seen a single 15 amp line power an entire floor, save for the bathroom!
So - you need to plan to either purchase some HEAVY DUTY power extension cords (THAT MUST BE PROPERLY RATED TO CARRY THE LOAD) - or go the professional way and get new lines run. If you do that, opt for 20 amp lines. You will know they are 20 amp because the wire is physically yellow (not white) and because 20 amp outlets look different. They look like this:
http://www.hometheaterhifi.com/volume_8_2/images/ps-audio-p1200-20-amp-wall-socket.jpg
They are rated just like 15 amp outlets, only require a 20 amp breaker. The extra costs are marginal really and a 20 amp line is rated for 1920 continual watts.
To power my Zins array, I installed a total of 3, 20 amp lines to give me a little room for expansion. If you live in an apartment or otherwise are unable to modify your living quarters, then extension cords will work - but PLEASE make sure your cords are rated appropriately. They can and will melt or catch fire if you overload them (by say, putting 20 amps through a 18 gauge extension cord and running it 300 feet away). If you don't know what you are doing - consult a professional. Electricity is not something you want to fool around with but is not something people should artificially fear either.
Ok - so now you have power.
Great.
You also have a 1500 watt heater running continually.
Most central or even zoned HVAC systems will not reliably cool a hot spot like that. Which means you need to either vent the air or cool it.
My setup requires somewhere on the order of 2 Tons of cooling capacity (24,000 BTUs) to keep things properly cooled down. The hotter you get, the most likely you will have hardware failures (hard drives in particular hate heat) and at a certain point, your machines will (should) physically shut down to prevent physical damage. In short - heat is BAD. When you "cluster" this many computers together - it adds up quickly.
Consider an average home, with average insulation and windows. Two tons of cooling will cool 800 square feet of area with the air conditioner running constantly. This will cool to about 20 degrees of inside vs outside difference. So, if the room is 120 degrees and you want to make it 80 degrees, then you need to double the cooling. Most average homes only have around 4 tons of cooling capacity - so cooling can get expensive pretty quickly. My server room is less than 800 square feet, so I can get away with around 2 Tons. 1 Ton portable units can be had for a few hundred dollars but keep in mind that ALL AC units work by moving hot air out. This is critical.
If you put an AC unit in the middle of the room and turned it on, it would heat the room! You need to move the air past the coils and outside. So whatever room you pick, you need to be able to route the air outside somehow. Window units work but are incredibly loud. If you don't go with a central system, don't want a portable unit then consider what is called a mini split. They are not very popular in America but get considerable use in Asia and Japan. Think of them as a quiet, permanent AC unit that splits the operation of the compressor (outside, loud) and the exchanger (quiet, inside). Most run $800+ and 2 Ton units are generally around $1500 without installation. But you need to do something to deal with the heat - unless you live in a constantly cool climate and can simply open the windows. Also - many AC units run off 240 volts, not 120 (in the US), so you (or your HVAC installer) need to think about how to get it power - or pick up a portable 120v unit instead.
In short - you need to think about cooling and power requirements. Take a look at the Dell calculator link http://www.dell.com/content/topics/topic.aspx/global/products/pedge/topics/en/config_calculator?c=us&cs=555&l=en&s=biz to better calculate your power use. Don't forget your other devices in the room. Check the back of most products or the power bricks to determine their actual power use. Some things may surprise you - each of my 30" monitors uses about 150 watts!
If you don't carefully consider your heating, cooling AND power requirements - you may wind up first in a sauna and then in the dark.
http://www.dell.com/content/topics/topic.aspx/global/products/pedge/topics/en/config_calculator?c=us&cs=555&l=en&s=biz
The below figures are for US households only. EU/Asia/Europa/etc will need to convert to your local values, which are most likely different than mine are right now (120v AC mains).
Also, this does not really apply to anybody who is not 5 or more boxing. When you start to stick 5 or more machines together (although at 3 or 4 you start to feel it) you wind up with plenty of heat. In a small room, this can be a problem. Even in a large room, if the room is well enough insulated or you live in a hot part of the world, the heat is produced faster than it can be dissipated.
I came along this nifty tool quite recently although I wish I had come across it sooner. It lists the cooling, heat/power, weight, rack units, airflow and current requirements/output.
If I were to redesign my systems from scratch, I would have bought a rack mount system but given the amazingly ridiculous cost of rack mount cases, I never bothered (we are talking $20 vs up to $200 per case!). That is just dumb. However, racks are specifically designed to allow for cooling and compact power use. So, if you want to 10 box and you don't care what it costs - by rack mounted units.
If you don't want to go that route - you still need to think about cooling and power consumption. 5 computers and other assorted goodies can quickly take up a single 15 amp line. In fact, I will venture to guess that MOST 5 box setups will encounter this problem, especially with older wiring.
A lot of people have absolutely no idea how much power their computers use. Most people don't need to - but it helps to have a general guide as to how much power use you are using. If you want to measure the power consumption at the wall (power supplies are only around 80% efficient, meaning they waste 20% more power in the AC->DC conversion process) then buy something called the Kill-A-Watt. It costs $30 at Thinkgeek and just works. http://www.thinkgeek.com/gadgets/travelpower/7657/
http://www.thinkgeek.com/images/products/zoom/kill_a_watt.jpg
There is a more sophisticated version called Watt's Up Pro for $130 but you don't really need that just to calculate power consumption. http://www.thinkgeek.com/gadgets/travelpower/7acf/
http://www.thinkgeek.com/images/products/zoom/wattsup_pro.jpg
Anyway, your cpu and video card use the most power by far. Modern processors can pull 75 watts easily (this is actually more due to inefficient power supplies). High end video cards can pull up to 200ish watts under full load. Motherboards only use around 10-15, memory 5-10, hard drives 10-20 (more on spin up) and usb peripherals only a few watts. Other add in cards can use more but figure an average modern computer will run you 250 - 300 watts of actual power draw under load. An average 15 amp household outlet will be able to run at 80% capacity over time. If you approach 100% over time, the wires will heat up enough and the breaker will trip. And keep tripping until you stop putting so much load on it. This keeps you from burning your house down. If the breaker were not there, you could overload the lines and cause them to overheat. Heat causes expansion of the connections (loosening them over time) or could outright cause a fire. Be thankful you have breakers.
15 Amps times 120 Volts = 1800 Watts. 80% of that is 1440. So a single 15 amp breaker can safely take 1440 watts continually all day and night, assuming the wire is in perfect condition and no other weirdness is going on (staples through power lines, frayed wires, etc). If each computer uses 300 watts, that is 1500 watts. Just for the computers. That does not count the monitors (17" LCDs figure 20 - 30 watts each) nor the room lights, or anything else you have on the circuit (speakers, tv, etc). MOST residential houses or apartments will only put a single 15 amp line to a single room. Sometimes only a single 15 amp line to two rooms - I have even seen a single 15 amp line power an entire floor, save for the bathroom!
So - you need to plan to either purchase some HEAVY DUTY power extension cords (THAT MUST BE PROPERLY RATED TO CARRY THE LOAD) - or go the professional way and get new lines run. If you do that, opt for 20 amp lines. You will know they are 20 amp because the wire is physically yellow (not white) and because 20 amp outlets look different. They look like this:
http://www.hometheaterhifi.com/volume_8_2/images/ps-audio-p1200-20-amp-wall-socket.jpg
They are rated just like 15 amp outlets, only require a 20 amp breaker. The extra costs are marginal really and a 20 amp line is rated for 1920 continual watts.
To power my Zins array, I installed a total of 3, 20 amp lines to give me a little room for expansion. If you live in an apartment or otherwise are unable to modify your living quarters, then extension cords will work - but PLEASE make sure your cords are rated appropriately. They can and will melt or catch fire if you overload them (by say, putting 20 amps through a 18 gauge extension cord and running it 300 feet away). If you don't know what you are doing - consult a professional. Electricity is not something you want to fool around with but is not something people should artificially fear either.
Ok - so now you have power.
Great.
You also have a 1500 watt heater running continually.
Most central or even zoned HVAC systems will not reliably cool a hot spot like that. Which means you need to either vent the air or cool it.
My setup requires somewhere on the order of 2 Tons of cooling capacity (24,000 BTUs) to keep things properly cooled down. The hotter you get, the most likely you will have hardware failures (hard drives in particular hate heat) and at a certain point, your machines will (should) physically shut down to prevent physical damage. In short - heat is BAD. When you "cluster" this many computers together - it adds up quickly.
Consider an average home, with average insulation and windows. Two tons of cooling will cool 800 square feet of area with the air conditioner running constantly. This will cool to about 20 degrees of inside vs outside difference. So, if the room is 120 degrees and you want to make it 80 degrees, then you need to double the cooling. Most average homes only have around 4 tons of cooling capacity - so cooling can get expensive pretty quickly. My server room is less than 800 square feet, so I can get away with around 2 Tons. 1 Ton portable units can be had for a few hundred dollars but keep in mind that ALL AC units work by moving hot air out. This is critical.
If you put an AC unit in the middle of the room and turned it on, it would heat the room! You need to move the air past the coils and outside. So whatever room you pick, you need to be able to route the air outside somehow. Window units work but are incredibly loud. If you don't go with a central system, don't want a portable unit then consider what is called a mini split. They are not very popular in America but get considerable use in Asia and Japan. Think of them as a quiet, permanent AC unit that splits the operation of the compressor (outside, loud) and the exchanger (quiet, inside). Most run $800+ and 2 Ton units are generally around $1500 without installation. But you need to do something to deal with the heat - unless you live in a constantly cool climate and can simply open the windows. Also - many AC units run off 240 volts, not 120 (in the US), so you (or your HVAC installer) need to think about how to get it power - or pick up a portable 120v unit instead.
In short - you need to think about cooling and power requirements. Take a look at the Dell calculator link http://www.dell.com/content/topics/topic.aspx/global/products/pedge/topics/en/config_calculator?c=us&cs=555&l=en&s=biz to better calculate your power use. Don't forget your other devices in the room. Check the back of most products or the power bricks to determine their actual power use. Some things may surprise you - each of my 30" monitors uses about 150 watts!
If you don't carefully consider your heating, cooling AND power requirements - you may wind up first in a sauna and then in the dark.