It is wrong. kWh is the number of kW multiplied by the length of time you consumed them for. Eg. if you draw 0.5kW for 2h, that will amount to 1kWh. You were consuming 0.5kW the first hour, 0.5kW the second hour, yet it was never "0.5kW/h", the total energy consumed was 1kWh.


At first your calculations look correct. But my friend's power bill, in the US, shows $0.10/kWh, yet he pays $0.17/kWh. This is because in another part of the bill, distribution charges are added ($0.06/kWh), and taxes ($0.01/kWh). My point is, reading all the fine print is hard. I don't know what your bill look like, so I am suggesting something simpler:
- how much did you pay for the last billing period (in VEF)?
- how much did you consume for the last billing period in kWh?
Surely your bill must show these 2 numbers, right? Divide the first number by the second one.


This is scarily low, and might explain your rate.

Kind of off-topic, but I am genuinely surprised and confused by this black market rate... I assume the local population favor the dollar over the bolívar, right? Why would they spend 8.6 VEF to get 1 USD on the black market, when they could just bring 4.3 VEF to a bank following the official rate?

Edit: Apparently dollars are rationed by CADIVI, so the population turns to the black market to obtain them. Makes sense...

Also, for the curious, assuming HD 7990 is a total of 4096 ALUs at 1GHz (two Tahiti XT), this single card will be capable of ~1.1Ghash/s.

Nice find. This shows the 7850 will be identical to the 6950 (VLIW4, same # of ALUs) but clocked at 850 MHz instead of 800MHz, and of course 28nm instead of 40nm.

Estimated HD 7850 hashing performance:
    1408 ALUs * 850 MHz / 3670 instructions per hash = 326 Mhash/s  (you can use this formula to estimate the performance of any VLIW4-based 69xx card)

Performance per Joule:
    326 Mhash/s / 90 W = 3.62 Mhash/Joule

Looks like my prediction will be shown as correct (>3.61 Mhash/Joule).

Yeah, I guess he doesn't want to bet as he basically ignored my entire last post...

Yep. NetTecture needs too to pay attention to details


Actually nuclear when done right is amongst the cheapest. Hydro is the cheapest. Nuclear second. Then coal/gas/wind/solar/etc.

As a matter of fact, France can generate most of its electricity so cheaply (because 80% is from nuclear power) that it has an economic incentive to resell it to its neighboring countries, which it does, making it one of the world's largest electricity exporter (some sources say the largest). Unfortunately these low costs are not passed to domestic users (they pay 0.12 EUR/kWH or 0.17 USD/kWh) I guess because of additional taxes... Compare to wholesale electricity prices in France which are 0.042 EUR/kWh or 0.059 USD/kWh: http://www.world-nuclear-news.org/C_EDF_wholesale_electricity_price_set_200411a.html

You want to bet against someone who has been developing ATI/AMD GPU apps for 3 years, who has been tracking and estimating the perf of their past and future GPUs for as much time, and who wrote the first CAL IL Bitcoin miner for Radeon cards? Sweet

Let's craft the terms of the bet more precisely. Especially let's take overclocking out of the equation as it is very variable from card to card (what if I claim I own a 7xxx card doing 800 Mhash/s? And you accuse me of photoshopping? We want results anybody can replicate.) As of today, the 5850, with a 151 Watt TDP, does 295 Mhash/s with the latest cgminer, at stock GPU clock, mem clock, and voltage. This is 1.95 Mhash/Joule. I predict that a 28nm 7xxx GPU will achieve at least 1.85 times this performance (3.61 Mhash/Joule) at stock GPU clock, mem clock, voltage, and all other settings, as benchmarked with cgminer 1.6.2 with the phatk kernel. If AMD fails to release a GPU matching my description by Sep 4, 2012 (a year from now), you win.

For example, I win if:
- a 100 Watt 7xxx card is released and achieves at least 100*3.61 = 361 Mhash/s
- a 150 Watt 7xxx card is released and achieves at least 150*3.61 = 542 Mhash/s
- a 200 Watt 7xxx card is released and achieves at least 200*3.61 = 722 Mhash/s

Let's bet 4 BTC. Deal? My email address is m.bevand at gmail.com, send me yours.

Except that for embarrassingly parallel applications, like Bitcoin, we actually saw a doubling of the performance (in fact more because the switch from the 55nm 4000 series to 40nm 5000 series also brought the BIT_ALIGN_INT integer rotate instruction.)

Bitcoin is not like "normal real-world applications"  

This figure is realistic. AMD has done it the past. With high-powered cards. They will do it again with the 28nm 7000 series.

- HD 4870 X2: 1200 billion instruction/sec / 289 Watt = 4.15 billion instruction/Joule
- HD 5970: 2320 billion instruction/sec / 294 Watt = 7.89 billion instruction/Joule -> 90% perf/Watt improvement

When performance/Watt is doubled, across the board, it doesn't mean we will see an end to ~300W cards like the 5970 or 6990. It means the same performance level will be achievable at half the power consumption, 150W, and AMD is going to continue to design cards for the 300W power envelope, except they will pack twice as much performance.

Hum, no. 1 ton of cooling is 3517 Watt.  So a 3-ton HVAC can cool about 10.6kW of equipment, or a bit more assuming heat loss in the server room.

Some use no HVAC to cool 10.6kW of equipment, but that's a completely different DC cooling strategy

As someone who doesn't pay attention to detail (it's "kWh" not "KW/h" ), you are almost certainly in error.

- Either the extra zero is a typo and you are in fact paying $0.11 per kWh
- Or $0.011/kWh is the generation cost and excludes the delivery cost, or vice versa (to know your effective rate, take your total amount billed and divide by our total kWh consumed)

Consider also that $0.011/kWh would be at or below the production cost of almost any hydroelectric dam in the world, including the Guri dam in Venezuela, which supplies 73% of the electricity in your country.

I agree.

I think the closest thing bitcoins can be compared to is rare collectible objects, traded by people, since there are a known limited number of them (21M).

Trini8ed: that's only if you buy 50k at once.

30k-100k I0C have been bought, daily, for the past few days with the price staying under .001 BTC.

A few persons have contacted me and seem interested. I will end the offer to sell the 5970 exactly 3 days from now, which leaves plenty enough time to buy 50k i0coins. I must receive payment by September 7 at 07:00 UTC. The block chain timestamp will determine if the sale will proceed or not. I will accept if the payment goes through 1 block late (ie. in the block immediately following 07:00 UTC). I will wait confirmation by an additional 40 blocks (nominally 1 hour) before acknowledging receipt of payment. Shipping is extra and will be arranged at the buyer's convenience (I accept USD/BTC/I0C).

How about a sane version numbering scheme? Call it 1.03.1.

Developers not using dots in their version numbers create confusion. Imagine a new user sees 2 versions for download: "1.04" and "1.031". He would logically think that "one dot oh four" was first released, followed by 26 releases, followed by "one dot oh thirty one" (and in this timeframe you switched from 2 to 3 digits after the dot). In fact, no! You had an implicit dot between "03" and "1", that has to be guessed based on how many digits your "normally" put after the first dot.

Or imagine you release many versions, reach 1.09, then 1.10, etc, 1.19, etc, 1.29, 1.30, and 1.31. At this point referring to "1.31" or "1.031" gets very confusing because some might think the leading zero is optional, or a typo, when in fact they are 2 very different releases.

/rant (in a former life, I wrote code to compare version numbers of thousands of applications)

Huh? AMD did precisely that when going from 55nm (HD 4870 = 800 ALUs) to 40nm (HD 5870 = 1600 ALUs).

They will do the same from 40nm to 28nm.

In fact it will be a bit easier this time to double performance because 55**2/40**2 = 1.89 but 40**2/28**2 = 2.04.

Volume has been 100k I0C in the past 24 hours, yet the exchange rate has stayed under 0.001 I0C/BTC. So I would say there is enough liquidity. You just have to buy slowly over time.

Price is now 50k i0c. This corresponds to an even lower 45 BTC, for a brand new HD 5970 at the current exchange rates!

Pay attention to my wording, guys.

I said 5000 vs 6000, not 5970 vs 6990.

You cannot generically state that the 5000 series is "cooler". The 5830 is terribly inefficient (Mh/J-wise) when compared to the 6990 for example. In fact, power efficiency overlaps a lot between the two series. And yes the 5970 is my personal favorite too.

I am selling an HD 5970 for i0coins: https://bitcointalk.org/index.php?topic=40880.0

We will see if that is futile or not ;-)

No, I don't have any outstanding order on any exchange. I am going long on i0coins.