Bitcoin Forum

I have 5 office machines at various locations that are rarely used but powered up ALL the time.  Each has 1 pci slot available.

Can I throw a 5850 in each of them and let them mine in the background?

And are ATI RADEON 5850 1GB PCI-EXPRESS DUAL DVI VIDEO CARD a good choice for this?

Maybe you *can* (tell us the motherboard model so we can check the PCI-E slot types), but *should* you? You didn't say if you pay for the electricity used or if you have permission from the bill payer. If you don't get permission, it's stealing. You will get caught, get fired or worse and it's not worth it.

Thanks for the help.  I did not build these machines and I can't even tell who made the board or its specs.  The slot is labeled, "PCIE16X". 

These are new, inexpensive machines from staples. 

It is my company, my machines, my electric bill so we are legit there.  I know at current levels this may not be profitable but I believe bitcoins will rise in value soon.  Also, it give me a tax benefit on the business side and lets me move value out of the company so I would like to do it if I can. 

All machines are running window 7 and I've installed Diablo Miner on the machines already.  They mine fine off the CPU of course it is ridiculously low hash rates. 

5850 is a good choice

make sure to use a miner like cg miner which can lower the memory speed alot to keep the cards cooler
because you will notice the extreme heat coming from them
and i would watch them closely for some time before they overheat
because business machine models are not the best cooled cases

You should be fine with it.

+1. cgminer could automatically lower the core clocks too if heat becomes an issue.

I would also check the PSUs in the rigs, OEM stuff from staples may or may not be up to the task of powering 5850s 24/7. the 5850 needs 2 x 6 pin PEG connectors. if the PSU lacks them they may come with the cards, or at least one should.

be prepared for some noise though heh.

Thanks everyone, I'm going to give it a shot for fun!

office computers rarely ship with a psu equiped to handle a 5830 or 5850 you may be in for a new power supply

How strong of a power supply is needed?

That depends on the age of the machine (a pentium 4 is also very demanding) but for a single 58xx card usually a 400-500 watt psu has a sufficently sized 12v rail, one like this is on the lower end of the spectrum it would handle a single 58xx or a pair of 57xx without too much trouble http://www.newegg.com/Product/Product.aspx?Item=N82E16817182202

Thanks

Be careful with PSU: I've recently bought a 650W one for one 5850 and it gave most of the power to the 5V, 3.3V lines and only a small fraction to 12V. So it was useless for my mining purposes.

Now this is what i found out myself with a brand new enermax 530w 85+, would you believe it can not handle 2 low power cards in a low power consuming machine.. By low power i mean a 75 w gt440 and a 116 w gts450
It simply can not handle the load (the system without the cards uses 106w on his internal gpu)
Every time i add the gt440 the system began to crash and constant went into bleu screens, with power failure messages on the cpu.
I put in my old trusty ocz 700w and no more crashes or problems at all, so somehow it seems that the powersupply are not really giving the power they should, ofcourse i would like to use the high efficient psu because the old power supply  probably consumes much more power to give a similar output. So for me enermax is not a good choice anymore
Especially since the shop returned the supply to me stating there was nothing wrong with it and send me a bill for 65 euro testing costs.

You always absolutely always need to check the rail configuration before buying a power supply, for mining look for single rail power supplies and make sure the majority of the capacity is on the 12v not 5v rails. older designs will still have the majority of their amperage on the 5v rail

In my experience with Windows 7 machines, i got the best hashrates from phoenix miner (tried everything from poclbm, cgminer, diablo etc.).

Recently switched to ubuntu linux and boy did that make a difference in stability! i went with the ubuntu 10.4 LTS which is extremely stable and gives me almost 0 rejects on slush's pool. in windows 7 it used to be 2 to 3 %

Getting linux mining up and running is a lot of work, mind you, but totally worth it.

PSU on my machines is 110w and there is absolutely NO WAY the cards will fit onto the MB! 

Oh, well.   

Build from scratch!

110w? sounds like an atom or celeron based machine