Bitcoin Forum

I started bitcoin mining with my new 7850 a while ago, and so far I've done a bit of mining. I've overclocked my video card from 860 MHz core to 1000 MHz (no overvolting). I mine using guiminer on the deepbit pool, and average about 280-300 MH/s consistently.

I have a few questions, though:

• What should my expected MH/s be? Is my current rate good?
• Are there any "extra flags" I should be putting in to maximize my rate?
• Would it be profitable for me to mine with this setup with an electricity rate of approx. $0.10 per kw/h?

Thanks in advance.

Hi there, i am Using the same card with about 260Mhash/s (at 920 MhZ core speed)
So for me it sounds quite good what you get ;)

Try DiabloMiner GPU Miner   Radeon 7xxx: -v 1 -w 256
280-300 MH/s is ok,try overclock core to 1100

Thanks for the tip logicus. With diablo miner i do get about 277mhash/s without overclocking and 310mhash/s at 1050MHz. That's 50mhash/s mrore (As much as my old nvidia card did in total :-P)

Well i have 7950 as well and I get about 530-560mhash


Use cgminer and the diakgcn kernel..

overclocked to about 1080 i believe. no voltage tweaks yet.. Temps are amazing.... 


 

2^32 hashes per share(on average) / 300,000,000 hashs/sec = 14 seconds per share or ~4.29 shares a minute.

24 hours / day * 60 minutes per hour * 4.29 = ~6171 shares a day.
BTCGuild pays 0.00003000296239776096 per share so you would make roughly .185 BTC/day or ~$1 @ 5.8 USD / BTC

There is two ways to look at power usage. Either you already have your computer on anyway, in which case you calculate only additional power usage from the GPU (which i believe is specced around 175 W) or total power to run the computer ( lets pretend you don't draw much power so lets assume 400W).

1. 175 W
  175 * 24 / 1000 = 4.2KWH * .1 USD =  $.42 / day

2. 400 W
  400 * 24 / 1000 = 9.6KHW * .1 USD = $.96 / day

So you are earning around $1 and spending around that if you computer is off normally. If your computer is on anyway then you are earning about double what you are paying in electricity.

Hope this helps.
Ben

Oh shit... I am so sorry.... I read 7950 not 7850... Please ignore my post :P

7850 OC here as well, and I get 260 MH pretty consistently. I haven't tried overclocking much at all but I think I could only get maybe an extra 2-3%.

At least the card is fairly electricity-inexpensive :D

I get with my asus HD7850 around 360 mh/s @1200mhz core... Thats not bad at all, and I only consume 220w (whole system) while mining at that speeds witout overvolting :D

oops, I just saw this tread is 120 days old O-O. Sorry! (happens when you search on google for HD7850 mining -,-)  :-X

http://www.powersearchingwithgoogle.com/

7850 sorta sucks... 300mhash? you can get that out of a cheap 5830/6870

For future reference, other cards and different settings have a look here:

https://en.bitcoin.it/wiki/Mining_hardware_comparison

just tested msi 7850 - best was diablo 3d miner with amdovdrvctrl : 337 Mh/s @ 1120MHz eng, 1000MHz mem.

You can get 330MHash easily using cgminer and only using the config file.  Normally you would use the AMD Catalyst thing to overclock but if you have your config file setup properly you can do everything there.  There is an example config file for the 330MHash/s rate at http://www.brandonorndorff.com/bitcoin/mining/radeon-hd7850-7870-cgminer-config-settings-bitcoin/ but it seems that it is increasing as he tweaks it.  Earlier today it said 300MHash and he has already tweaked another 30mhash out of it.  The best part is it it running at only 58 degrees or so.

Im following that closely since I am using a rig with 3 7850's in it and was only getting about 240MHash each before finding the post above.  Hopefully he can get it up closer to 400MHash/s before he stops tweaking :)

But the former will draw some 175 W while 7850 only 130.

I'll describe my experience with an Asus 7850, and try to compare with the previous post.

It comes factory "overclocked" to 1000 MHz (engine), default memory @1250.
The AMD CCC allows engine overclocking up to 1050.
OTOH, memory clock can't be set lower than 150 MHz below the engine.
So, in my case it would not be possible to use 1100/900 setting ftom the randonorndorff page, even if I'd overclocked the engine to 1100 with CGminer, which is possible. I'd then have to set memory clock to 950. With my 1050 MHz engine clock, I've to leave the memory at 900 MHz.

Another interesting thing I can see in the linked page settings is the usage of poclbm kernel. Which is not the default CGminer kernel AFAIK.
But it's the default one in GUIminer. When I had tried CGminer with the same frequency settings (1050/900), it had crashed from time to time, while it was pretty stable with GUIminer. One idea was that cgminer's default kernel gets a bit more from the card at the price of a bit higher power consumption, which the PSU can't supply. But it has been neither confirmed nor invalidated.

With the above settings, I've been getting slightly above 300 MH/s from the card.

hi, i now have 2 of these mining along side 2 7770's. and with MSI afterburner (did the whole config addition of the promise that i knew i was doing something that might hurt my equipment and might not be covered by manu... all that) and without a voltage increase- core clocked at 1241Mhz. 

has been stable for weeks now without a hiccup at ~363Mhash/s

hope this helps, these are great vale cards, and they run nice, smooth and quiet

Happy Mining!!!

Xmasautopsy