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1221  Bitcoin / Bitcoin Discussion / Re: Why $17?? on: June 30, 2011, 08:21:28 PM
Most members of the crisis got free transaction fees.


If it goes up 10 cents, they profit. So they aren't sitting on their investment as long. They are buying and selling at the same time, kind of like playing pong with your own two hands.

For example: you place 100 buy orders to the left side of the midpoint, and 100 sell orders on the right side.

Let the computer do all the work.

This is what I meant by an "ideal" market. With zero commissions for certain active traders, the spreads are very narrow because market making as you describe it can return a profit, e.g. 0.001 BTC on tiny spreads.  The spread should widen only when volatility increases, which according to market theory arises because of the sudden entrance of "informed" traders into the market, e.g. some merchant needing to unload 1000 BTC at market.
1222  Bitcoin / Mining / Re: Electricity to cool the house when mining on: June 30, 2011, 07:44:40 PM
Quote
I hope you have a dehumidifyer nearby or else that rig will be toast soon.

Right now the humidity in Austin, Texas is 45%.  My house is pier and beam construction which elevates it 4 feet above the rocky soil under the house.  Because the house is on top a ridge, the crawl space has been bone dry for years. Dust might eventually be an issue but the CPU and GPU fans seem to keep their respective radiators clean enough.  As purpose-built mining rigs, I chose a conservative configuration with respect to heat dissipation.   There are only two GPUs per mother board, and there is sufficient space between the cards for unobstructed airflow.  I chose Radeon HD 5770 CPUs that draw somewhat over 100 watts when overclocked.  Likewise I chose the least power consuming CPUs for the motherboards. The three rigs have six 5770 cards and in total draw 860 watts from the socket.  

Some may not be aware that recently Intel has been conducting research on whether datacenter air conditioning could be relaxed a bit.  This article: http://www.datacenterknowledge.com/archives/2008/09/18/intel-servers-do-fine-with-outside-air/ gives details.

I'm not ignoring a possible fire danger with six overclocked GPUs.  I have the power supplies sitting on pieces of floor ceramic tile, and the case-less motherboards elevated a bit off the small sheet of plywood that supports them.

Here are temperature and clock readings from one of the rigs, that I control from my home office via ssh.  Note that the outside air temperature is 38 C (100 F), the crawl space is a steady 30 C (86 F).  The rig produces 424 MH/sec using poclbm.

user@linuxcoin02:~$ DISPLAY=:0.0 aticonfig --odgt --adapter=all

Adapter 0 - ATI Radeon HD 5700 Series
            Sensor 0: Temperature - 65.00 C

Adapter 1 - ATI Radeon HD 5700 Series
            Sensor 0: Temperature - 56.00 C

user@linuxcoin02:~$ DISPLAY=:0.0 aticonfig --odgc --adapter=all

Adapter 0 - ATI Radeon HD 5700 Series
                            Core (MHz)    Memory (MHz)
           Current Clocks :    960           1200
             Current Peak :    960           1200
  Configurable Peak Range : [500-960]     [1200-1445]
                 GPU load :    99%

Adapter 1 - ATI Radeon HD 5700 Series
                            Core (MHz)    Memory (MHz)
           Current Clocks :    960           1200
             Current Peak :    960           1200
  Configurable Peak Range : [500-960]     [1200-1445]
                 GPU load :    99%


 

1223  Bitcoin / Mining / Re: Electricity to cool the house when mining on: June 30, 2011, 04:00:16 PM
Here is tutorial on A/C costs for large office installations that scales well to bitcoin mining rigs. http://joule.bu.edu/~hazen/LinuxCluster/actut.pdf

A quote from that article ... "Typical air conditioning systems would require 0.5 BTUs of energy to remove 1 BTU of heat."

By the way, knowing the expense and discomfort of running an 850 watt bitcoin mining farm inside my house, I situated my three rigs outside my house.  They are in the crawl space under it where the ambient temperature is 30 C / 86 F, even when the outside air is 100 F here in Austin, Texas, USA.
1224  Other / Beginners & Help / Re: mtGox Trading API down? on: June 30, 2011, 03:47:59 PM
Have the same Problems.
By the way...Anyone knows an existing Java implementation für the Mt.Gox-API ? I have Problems to set a POST https-message.
If anyone has a short JAVA-script for me, i would be so thankful!

Hi.  Did you see my Java HTTPS snippet posted to your request on another thread?  If not, just respond here and I'll post my latest Java POST to get the Mt Gox funds balance - assuming that one is properly logged in.
1225  Other / Beginners & Help / Re: mtGox Trading API down? on: June 30, 2011, 03:31:21 PM
I just tried my test scripts for the Mt Gox Trading API and they also gave me the reported error.  However in my development work yesterday I discovered a sequence of commands that works.  Once logged in, only the last command needs to be input.  These are using the curl linux command line utility.  And I also have a Java version that I'm now updating to recover from the reported error using this protocol.  Note that the user and password must be HTML encoded.

Code:
curl -v -k --referer https://mtgox.com https://mtgox.com/users/login

curl -v -k --referer https://mtgox.com/users/login --data "name=XXX&pass=YYY" https://mtgox.com/users/login

curl -v -k --referer https://mtgox.com/users/login https://mtgox.com/

curl -v -k --referer http://mtgox.com/ --data "name=XXX&pass=YYY" -H "Accept: application/json" https://mtgox.com/code/getFunds.php
1226  Bitcoin / Bitcoin Discussion / Re: Why $17?? on: June 30, 2011, 12:51:50 PM
There is almost zero spread on Mt Gox because certain active traders were granted zero commissions for 30 days following the security problem.  Without commissions to compensate for, bid and ask prices sometimes agree to four significant digits! This situation represents an "ideal" market.
1227  Bitcoin / Mining support / Re: poclbm issue on: June 30, 2011, 07:09:24 AM
Is your screen powered off, or is it possible that a CPU-hogging screensaver has started?
1228  Economy / Trading Discussion / Re: Is the Mt Gox POST API working? [SOLVED] on: June 30, 2011, 06:07:45 AM
It turns out that the Mt Gox trading API for obtaining balances is working fine with a single HTTPS POST.

Here is the curl command that I use from linux ..
Code:
curl -v -k --referer https://mtgox.com --data "name=XXX&pass=YYY" -H "Accept: application/json" https://mtgox.com/code/getFunds.php

The referer header content is not important.  The user name and password are HTML encoded.

My Java code now matches the behavior of the working curl command.
1229  Economy / Trading Discussion / Re: Is the Mt Gox POST API working? [SOLVED] on: June 29, 2011, 07:57:27 PM
OK so I traced the HTTPS headers and contents from my web login to Mt Gox.  The Google Chrome browser has a Network diagnostics screen in its Developer Tools menu.  From there I could inspect the headers and contents sent to Mt Gox as I logged in using their web interface.  I found to my delight that I could copy the POST content from the web login screen and obtain a valid login using the linux curl utility.  Following the login, the Mt Gox trade API POST command getFunds worked OK.

Here is the sequence of HTTPS commands that I used.  I expect that I can get them running also in Java now that I know what Mt Gox accepts.
Code:
curl -v -k --referer http://mtgox.com --cookie-jar cookies.txt https://mtgox.com/users/login

curl -v -k --referer https://mtgox.com/users/login --cookie-jar cookies.txt --data "login%5BUser%5D=XXX&login%5BPassword%5D=YYY" https://mtgox.com/users/login

curl -v -k --referer https://mtgox.com/users/login --cookie-jar cookies.txt https://mtgox.com/

curl -v -k --referer http://texai.org --cookie cookies.txt --cookie-jar cookies.txt  --data "name=XXX&pass=YYY" -H "Accept: application/json" https://mtgox.com/code/getFunds.php

-->
{"usds":2.9915,"btcs":1}

Note that the user and password POST fields have been HTML encoded.  I used the same strings as I detected in the Google Network diagnostics, but it should be possible to use any online HTML escape tool to figure the escaped strings if your programming environment does not have a handy method.

1230  Economy / Trading Discussion / Is the Mt Gox POST API working? [SOLVED] on: June 29, 2011, 06:49:56 PM
I am developing a Java API for Mt Gox.  I have the GET methods working fine, i.e.

Ticker Data:   https://mtgox.com/code/data/ticker.php

But I get {"error":"Must be logged in"} when testing from Java.  I can see all the details of the HTTPS communication using the curl utility on linux, which gets the same error message ...

Code:
curl -v -k --referer http://bitcoin.org --cookie-jar cookies.txt https://mtgox.com/code/data/ticker.php

curl -v -k --referer http://bitcoin.org --cookie cookies.txt --cookie-jar cookies.txt  --data-urlencode "name=XXX&pass=YYY" -H "Accept: application/json" https://mtgox.com/code/getFunds.php

The first curl command gets the Mt Gox ticker OK, Note that the SESSION_ID from the ticker GET is sent back to the Mt Gox server with the subsequent POST via curl's cookie options. The second curl command responds with the above mentioned error.

I may have to resort to screen scraping the Mt Gox web pages, i.e. pretending to be a web browser if I cannot get the Mt Gox trading API to work for POSTs.

Any help would be appreciated, - if you do not know how your script works, just knowing that someone has a working script to obtain Mt Gox balances would be useful.
1231  Bitcoin / Mining software (miners) / Re: Which miner + settings are best for my setup (currently ~1.7 Ghash/s) on: June 29, 2011, 03:19:16 PM
When I experimented with phoenix, it drove up my CPU utilization, so I chose to stay with poclbm.

I get about 3% CPU utilization per poclbm mining process.  Could anyone using phoenix report their CPU utilization figures?

At the time of my experiment I feared that phoenix was performing CPU mining in addition to GPU mining in order to elevate the hash rate, but as everyone knows, CPU mining is not at all cost effective considering the additional watts consumed.  Is this fear justified?
1232  Other / Beginners & Help / Re: A got bot Ai for trading ? on: June 29, 2011, 03:10:39 PM
Be aware that Mt Gox spreads are currently very efficient - tiny,  due to the fact that many active traders there were granted a month's worth of transactions with no commissions when their in-place trades were rolled back.  Other traders at Mt Gox are paying .3 % for thirty days I think.

Any new HFT (high frequency trading) bot will have to take this commission disparity into account immediately, or simply wait out the 30 days or so until presumably commissions for everyone revert to .65 %.  If your trading algorithm does not depend upon fair spreads, i.e. the current Mt Gox situation, then go for it.
1233  Other / Beginners & Help / Re: Some Bitcoin Calculations on: June 29, 2011, 02:53:53 PM
Here is a more detailed chart of difficulty increases from http://bitcoin.sipa.be/speed-lin-10k.png

Your profit projections must make some allowance for difficulty increases.



1234  Other / Beginners & Help / Re: JAVA implementation for Mt. Gox API needed on: June 29, 2011, 02:05:14 PM
Is there nobody out there, who has something like this implemented? I need really only a code-fragment which grabs the ticker-data from Mt. Gox...

I have not yet tried POST on Mt Gox.  Because their websocket API is non-responsive, I have been polling their published ticker API ...


Code:
    final String httpsURLString = "https://mtgox.com/code/data/ticker.php";
    final StringBuilder stringBuilder = new StringBuilder();
    try {
      final URL url = new URL(httpsURLString);
      final HttpsURLConnection httpURLConnection = (HttpsURLConnection) url.openConnection();
      final InputStream inputStream = httpURLConnection.getInputStream();
      final InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
      final BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

      String inputLine;

      while ((inputLine = bufferedReader.readLine()) != null) {
        stringBuilder.append(inputLine);
        stringBuilder.append(' ');
      }

      bufferedReader.close();
    } catch (IOException ex) {
      // report exception
    }

    final JSONObject jsonObject1 = (JSONObject) JSONValue.parse(stringBuilder.toString());
    final JSONObject jsonObject2 = (JSONObject) jsonObject1.get("ticker");
    final BigDecimal bidPrice = new BigDecimal(jsonObject2.get("buy").toString());
    final BigDecimal askPrice = new BigDecimal(jsonObject2.get("sell").toString());
    final BigDecimal lastPrice = new BigDecimal(jsonObject2.get("last").toString());
    final BigDecimal highPrice = new BigDecimal(jsonObject2.get("high").toString());
    final BigDecimal lowPrice = new BigDecimal(jsonObject2.get("low").toString());
    final BigDecimal volume = new BigDecimal(jsonObject2.get("vol").toString());


The json-simple1.1.jar is a dependency.  I used keytool to import the Mt Gox SSL certificates from my web browser into cacerts, as I previously deleted all X509 certificates from that keystore as a security precaution.
1235  Economy / Trading Discussion / Re: cross-exchange trading on: June 29, 2011, 03:25:54 AM
Enjoy it while you can, until the exchanges network with each other. Smiley

What motivation would bitcoin exchanges have to network their open orders? 

For example, why would Mt Gox link with a lower volume competitor.  Arbitrageurs conduct transactions that are subject to exchange fees.  If arbitrage is no longer possible, then the exchanges lose that transaction volume.

More likely, larger exchanges will purchase smaller exchanges.
1236  Other / CPU/GPU Bitcoin mining hardware / Re: Minimum system on: June 29, 2011, 03:14:49 AM
Agreed with cheapest MB, CPU, RAM to support two PCIe slots.  I have three such rigs that when overclocked together draw 850 watts from the socket.  I use a USB stick to hold the linuxcoin OS - you really do not need a hard disk drive.  I use a 600 W power supply for each rig.

I also do not use any cases - better airflow - despite operating against consumer protection laws for electronic emissions.
1237  Other / CPU/GPU Bitcoin mining hardware / Re: Designing Bitcoin Case from the Ground Up on: June 29, 2011, 03:10:23 AM
I think that you can design two styles of cases ...

1. Gamer cases may not have sufficient airflow directed over three or four closely spaced GPUs mounted directly on the motherboard.  More airflow means lower temperatures and thus more overclocking headroom.  Your first design could have a high-volume fan with possibly a duct right over the row of GPU cards.

2. Many miners are forced to go case-less when dealing with multiple GPU cards per motherboard using PCIe ribbon cable extenders.
Look at the photos of case-less rigs on the mining rig photos thread here: http://forum.bitcoin.org/index.php?topic=7216.0 to see what I mean.  Your second design could have a bar to which the front of the GPU cards are mounted with screws and a second bar to support the rear of the cards.  Because most high performing mining GPUs are double-wide, they are simply too close together on a motherboard allowing more than two double-wide PCIe GPUs.  This particular design allows spacing out the GPUs, provided that they are connected to the motherboard with PCIe ribbon cable extenders.

Good luck.
1238  Other / CPU/GPU Bitcoin mining hardware / Re: Yet Another Video Card Comparison... on: June 29, 2011, 03:04:58 AM
Excellent chart. Thanks for that.

I'd like to pick up a couple 5770.
Do I need to look for reference design or unlockable specs?
Will any mfr. do fine? I've seen Asus, Saphire, HIS, XFX. All good?
Thanks!

I found that Sapphire 5770 GPUs have better fans and heatpipes that keep the temperature about 10 C cooler than alternatives.
1239  Bitcoin / Mining software (miners) / Re: another 3% mining increase with poclbm kernel.cl on: June 27, 2011, 10:12:41 PM
Quote
what can I switch to that won't drop my hashrate but will lower CPU usage?

You could try poclbm, as I do not know much about configuring phoenix.  
1240  Other / Beginners & Help / Re: Video Card on: June 27, 2011, 09:58:15 PM
Yeah, I keep seeing that.....Okay, So 5 rigs with 4 5850s each. I think that is the past I'll take.

After choosing your graphics cards, its important to now consider the number of rigs.  As with GPUs, there are several independent features to optimize ...

1.  Fewer motherboards, i.e. five rigs, mean fewer disk drives or USB sticks to contain the operating system, fewer CPUs, fewer network cables, less shelf space, and easier hardware monitoring - in that you either have to hook up a monitor, mouse and keyboard to a motherboard in order to work on it, or using Linux, e.g. linuxcoin, one can ssh into the rig to see all the attached graphics cards.  Fewer motherboards may mean fewer power supplies, but gaming-style power supplies can be more expensive when capable of powering say four overclocked 5850s - maybe 1200 watts per single power supply or simply two less expensive power supplies per motherboard.  Motherboards having four PCIe slots are more expensive than those having say two PCIe slots.  See the forum thread for mining rig photographs for ideas on how to cool packed GPU cards, or to move them away from the motherboard using PCIe extension cables.

2.  More motherboards, i.e, ten rigs with two 5850s each, on the other hand may be more expensive in total than the alternative (1) above, but they are far easier to cool - as the cards are twice as far apart and the GPU fans have a much better inflow.  Commodity motherboards permit the use of much less expensive power supplies - say 600 - 850 watts apiece.

3.  Consider whether  to enclose the rigs in cases.  Operating without a case may violate certain consumer protection laws against electronic emissions but the practical reality is that many miners, and myself do so.  Cases very much restrict airflow, but compensate somewhat by adding fans.  If noise and component clutter are not an issues, consider operating without cases.  Again, one can get many ideas from the mining rig photos posted in the hardware forum.
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