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Bitcoin Discussion Thread Part 2

Spare-Flair said:
Measured power consumption one 6870 card
System in IDLE = 173W
System Wattage with GPU in FULL Stress = 295W
Difference (GPU load) = 122 W
Add average IDLE wattage ~ 19W (ATI specified)
Subjective obtained GPU power consumption = ~ 141 Watts

Measured power consumption two 6870 cards
System in IDLE = 184W
System Wattage with GPU in FULL Stress = 421W
Difference (GPU load) = 237W
Add average IDLE wattage x2 ~ 19W (ATI specified)
Subjective obtained GPU power consumption = ~ 275 Watts

Adding another card is 30% increase in power consumption. If you really are @ 250W, then it'd be around 325W for your system = $1.01/day @ $0.13/KWh but you would make 1 BTC ($6.50) in 2.6 days or $1.50/day in profit.
Click to expand...

There are tweaks you can do to increase your hash per watt figures too. Downclocking the memory on my system dropped 50watts, im just starting to play with underclocking and undervolting to maximzie my efficiency. One guy on here showed 7970 going from 670m/hash a sec at 267watts (1.125v) to 550m/hash sec at 118watts (.83v)
 
I have my 7970 doing 550mh/s, stock clocks and undervolted to 1.03

70C at 40% fan speed

AB won't underclock my memory though, anyone have this problem?
 
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jojo69 said:
Just a note, of course folks are free to do whatever they wish, but I urge anyone tempted to hash for the Eligius pool to look into it carefully. There has been a lot of chatter on the forums accusing the operator, one "Luke Jr." of using his pool's hash to attack other cryptocurrencies.

Sethmo, yeah, I'm down with ARSB, I'm glad folks realize that too big is a problem.
Click to expand...

This post explains what Luke Dash jr,owner of the Elgius pool did:

https://bitcointalk.org/index.php?topic=56791.0

In a nutshell,he used his pool to launch a 51% attack on one of the Alternative currencies effectively killing it.

He did this without asking his miners permission which is a huge breach of trust.

I would strongly advise against using his pool as he seems hellbent on stopping other crypto currencies being developed and improvements being introduced
 
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yowen said:
I can do that on Monday. I have the excel file on my work computer.
Click to expand...

https://docs.google.com/spreadsheet/ccc?key=0AiV7gBjnYuyzdEdXOTBCRHQ3RTJUa0NILUhTWk1NYkE

Here's a link, the fields highlighted in yellow are the ones that need to be edited to get an accurate number for your specific situation.

I've put in a bunch of columns for individual use, so if you make a new column you can title it with your graphics card, we'll see how well it goes, haha. Feel free to add any notes to the bottom of a column.
 
Sorry if I screwed up anyones entries in the Google Doc, didn't realize it was a public document lol.
 
I think we lost a couple entries, lol. But everything looks good now.

The 1400 mhash/24 hrs number I got out of this thread. Is this an accurate number (on average) to get to 1 BTC?
 
Might want to change the columns to calculate the Price/kwh to the top of each column so each person can use their own kwh price :)
 
I have been wrestling with that.

I like 1 spot for the kwh price. As it will allow you to quickly evaluate a large number of setups at a given kwh rate.

But I guess on the other hand, it could get messy that way with multiple people trying to do so.
 
Yeah, could just leave it how it is. I made a column for me and made my kwh calculate from the number at the top of the column. Other people could just do the same.

Will be interesting to see how many watts/mhash other [H] members are putting out.

Again, sorry if I deleted anybodies first entries! :p
 
sethmo said:
Yeah, could just leave it how it is. I made a column for me and made my kwh calculate from the number at the top of the column. Other people could just do the same.

Will be interesting to see how many watts/mhash other [H] members are putting out.

Again, sorry if I deleted anybodies first entries! :p
Click to expand...

Good idea, added a row for mhash per watt
 
And out of curiosity, do you guys with some more elaborate setups report this as income on your taxes? What are the implications?

edit: I gave in and did individual power costs
 
The spreadsheet is fun. I'm am guesstimating my wattage from a kill-a-watt on one triple 5870 machine which reports power draw at the wall which should take care of the entire system + efficiency.

3x 5870 on that machine is about 750W for me. Adding a single 6950 to that machine pushed it to 900W.
 
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Strange, the 6950 should not be putting out 250w. I need to put my Kill-a-watt on my 2x6950 rig. Numbers would be little high though as it is an X6, 8gb ram, SATA HD, etc.

I put a Kill-a-watt on one of my 4x5830 machines and it ran consistently at 755-760w.

I had two 4x5830 rigs connected to one Kill-a-watt and have fried two Kill-a-watts now. I stopped using them on a regular basis. I wonder if I can get them replaced, they only lasted about 2 weeks each :(
 
Lol yeah, I started looking at all these numbers and absolutely could not resist, I had to make a spreadsheet, haha.

Funny thing is, I haven't even tried bitcoin yet. I see possibilities for a setup in my bedroom though... As it is way colder there than the rest of the apt. Haha.
 
sethmo said:
Strange, the 6950 should not be putting out 250w. I need to put my Kill-a-watt on my 2x6950 rig. Numbers would be little high though as it is an X6, 8gb ram, SATA HD, etc.

I put a Kill-a-watt on one of my 4x5830 machines and it ran consistently at 755-760w.

I had two 4x5830 rigs connected to one Kill-a-watt and have fried two Kill-a-watts now. I stopped using them on a regular basis. I wonder if I can get them replaced, they only lasted about 2 weeks each :(
Click to expand...

Remember that draw at the wall is significantly higher than what the draw your cards will pull because of inefficiency in the PSU and other factors.

But you are right, I misremembed. That was when I had 4x5870 on that machine for 1000W, not 3x5870+6950. The 6950 was more like 900W so only 150W.
 
silent-circuit said:
Only trouble is, mining means noise, and most would rather not deal with heavy fan noise in their bedroom...
Click to expand...

Mining in your bedroom is absurd. You would bake to death and lose your hearing. I do have a triple 5870 setup in my room but it uses the Gigabyte dual fan 5870s which are quieter. It heats the place in winter but I have to use earplugs if I am going to sleep in there which I usually don't.
 
I don't have any of my rigs in my bedroom, but I haven't had a PC in my bedroom since college :p
 
Who was the user in pink filling out the breaker, amperage, voltage, information? That was useful. I used to regularily blow my breaker when I had 6x 5870 on one breaker back in summer. Must have been a 20A breaker in a very old house which was less efficient.
 
That was me. I am trying to figure out how to place all of my rigs in the same room and have sufficient power to each without tripping breakers lol. I need to find a friend with a garage and easily accessible breaker box :p

And it was probably a 15A breaker as a 20A breaker should be able to handle 6x5830s split between two rigs(~1500w)
 
sethmo said:
That was me. I am trying to figure out how to place all of my rigs in the same room and have sufficient power to each without tripping breakers lol.
Click to expand...

You will need an industrial NEMA power connection for the 40A your need for your 3 kilowatts! How are you going to cool 2x6950, 8x5830, 2x5850, 2x5870 in one room? In summer, even two 5870s in one room with the window always open was unbearable and hard on the fans.
 
Lol, laundry room it is! Should've realized that some gpu fans cranked up would be redic to sleep with... I just tried to think of the room in my apt that draws the least power and the only thing in my bedroom is a light and an alarm clock. Laundry room is tiny, it would get HOT in there :p

lol someone added [h] [h] [h] [h] [h] [h] to the sheet...
 
yowen said:
Lol, laundry room it is! Should've realized that some gpu fans cranked up would be redic to sleep with... I just tried to think of the room in my apt that draws the least power and the only thing in my bedroom is a light and an alarm clock. Laundry room is tiny, it would get HOT in there :p

lol someone added [h] [h] [h] [h] [h] [h] to the sheet...
Click to expand...

The benefit of the laundry room is that the breaker in the laundry room is usually the beefiest in the entire house to support the power req of the washer/drier.

When my miners are plugged into the wall in my room if I use a hairdryer or vacuum cleaner or steamer, I have tripped the breaker before.
 
Yeah, I guess I'll have to look into the power draw of the dryer though, as I'd like to continue using it :p
 
Spare-Flair said:
You will need an industrial NEMA power connection for the 40A your need for your 3 kilowatts! How are you going to cool 2x6950, 8x5830, 2x5850, 2x5870 in one room? In summer, even two 5870s in one room with the window always open was unbearable and hard on the fans.
Click to expand...
I am awaiting my 2x5850 and 2x5870 right now, but I have not had any problem running 2x6950 and 2x 4x5830 rigs in one room. Right now it is winter and I just leave a window open.

Winter temps(Wind blows directly against my house, and it has been windy this winter!)
6950s: 51C, 58C with window half open
5830s: 37-45C

Summer temps were warmer, and my office was warm, but it was not out of control:
6950s: 58-70C depending on if the AC was on
5830s: 60-70C depending on if the AC was on

I am not sure what I am going to do yet this summer with the addition of 2 5850s, 25870s, and possibly 4 more 5870s. I dont need all the rigs on one circuit, but if I could have them split between 2 or 3 20A circuits, and keep them in the same room, that would be ok. The problem is that my office is on the second floor and adding additional wiring is a pain, so I need to find a new home for my rigs, closer to a breaker box.
 
I have no AC so in summer, the rigs have to goto the basement. Even then, it becomes tropical down there. I am not sure how I will continue through the warmer months. It was tough last summer.

We'll see if it is still profitable by then. Judging by what happened when BTC dropped to $2.50, people quit. So that should be an okay pressure on BTC difficulty in case of a rise this year. Not everybody has cheap/free electricity.
 
Spare-Flair said:
I have no AC so in summer, the rigs have to goto the basement. Even then, it becomes tropical down there. I am not sure how I will continue through the warmer months. It was tough last summer.

We'll see if it is still profitable by then. Judging by what happened when BTC dropped to $2.50, people quit. So that should be an okay pressure on BTC difficulty in case of a rise this year. Not everybody has cheap/free electricity.
Click to expand...

So the value of a BTC tends to drop during summer?

Man no AC, just running my gaming pc during summer made my room hot back when i didn't have AC, can't imagine running 24/7...
 
yowen said:
Yeah, I guess I'll have to look into the power draw of the dryer though, as I'd like to continue using it :p
Click to expand...

The [H]ard response is that you will hang your clothes so the hot exhaust of your video cards will dry the clothes.

Two benefits, dry clothes and the evaporation of the water cools the overall room temp. :) Less power consumption overall.
 
yowen said:
So the value of a BTC tends to drop during summer?

Man no AC, just running my gaming pc during summer made my room hot back when i didn't have AC, can't imagine running 24/7...
Click to expand...

No, the value of BTC is unpredictable and can be affected by rumors and panics. In the summer it was $15/BTC. By November it was $2.50/BTC.

The summer just means it's hot and miners generate a lot of heat adding to the problem of keeping them cool and not burning up your videocards and burning down your house.

What is going to happen is that as more and more miners start mining, the difficulty increases and therefore you will make less BTC per hash. IE: if difficulty doubles, you will make 2 BTC/day instead of 4 BTC/day like you might make today. What happened when BTC dropped to $2.50 is that a lot of people no-longer made money or lost money so difficulty went down significantly for the first time ever. If it stays around $6 or goes higher, miners are going to start coming back in and raising the difficulty for everyone.
 
Spare-Flair said:
The benefit of the laundry room is that the breaker in the laundry room is usually the beefiest in the entire house to support the power req of the washer/drier.
Click to expand...

The 120V outlets will be the same (15A circuits) as you'll see in the rest of the house. If it's setup for an electric dryer, that will be on its own 240V circuit.
 
Roadhog said:
I did some 7970 bitcoin testing here.
https://bitcointalk.org/index.php?topic=57410.msg683755#msg683755


Three 7970's:

System Idle: 270 watts

Mining: 925/150mhz, 865mv, 354 watts

~1650mh/s
Click to expand...

I tried plugging in your values into the spreadsheet. Am I reading this right? At your best performing overclock+undervolt+mem downclock, it's 270W + 354W = 624W at the wall for a 1650mh/s system?

I'm getting a crazy 2.64 MH/W efficiency reading on that.

https://docs.google.com/spreadsheet/ccc?key=0AiV7gBjnYuyzdEdXOTBCRHQ3RTJUa0NILUhTWk1NYkE#gid=0
 
That seems to beat out anything so far, at 2.64 mhash per watt... Too good to be true?
 
yowen said:
That seems to beat out anything so far, at 2.64 mhash per watt... Too good to be true?
Click to expand...

It would be fun to have another row so people can fill in total cost of parts to see how much money each system costs and how long it takes to pay them off.

3x7970 might be 2.64MH/Watt but it also costs $1650.00 for the 3 cards. Since he's getting 1650MH/s. That's $1/Megahash spent on videocards! (not even including cost of the rest of the system).

4x5870 will also get me about 1650MH/s but that only cost me $800. That's $0.48/MH per videocard.

In the long term, the higher efficiency of the 7970s will pay them off but that would take 8 months to pay them off.
 
Spare-Flair said:
It would be fun to have another row so people can fill in total cost of parts to see how much money each system costs and how long it takes to pay them off.

3x7970 might be 2.64MH/Watt but it also costs $1650.00 for the 3 cards. Since he's getting 1650MH/s. That's $1/Megahash spent on videocards! (not even including cost of the rest of the system).

4x5870 will also get me about 1650MH/s but that only cost me $800. That's $0.48/MH per videocard.

In the long term, the higher efficiency of the 7970s will pay them off but that would take 8 months to pay them off.
Click to expand...

Added in "cost per Mhash" row, but didn't pre-enter the calculations, as not everyone will be filling it in, so i didn't want to see a bunch of divide by zero's, lol.

Bitcoin Calculation Spreadsheet
 
Added my current numbers to the sheet, hope to update / improve them soon. I really need to undervolt and drop memory clocks, as well as undervolting my CPU. Gotta get my efficiency up since I pay so much more for power than most here. I'm still in the black so long as return and difficulty stay close to where they are now, but when and if it doubles or return drops substantially there's no reason for me to mine. Luckily I never built my system with mining in mind, it's just a nice bonus.
 
Yeah... With my cost at 13 cents per KWH I'm not sure I want to get into it, for me it would mean building a system. Which I could do fairly cheaply, but cheaply enough? The thing is, I wouldn't have a use for the system afterward (like you do silent-circuit).
 
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