I'm using an old Precision 690 chassis to host my two 5830's, one at ~310 MHash/s and the other at ~290 Mhash/s.

Like the others said, pull out all the extra bits -- I removed firewire, SAS controller, extra drives, RAM extenders, all but two DIMMs, and one of the CPUs.

Basically for a dedicated mining rig these parts serve no purpose but to waste electricity by making pointless heat.

The Amperage limit is on your breakers, usually in the garage.  You can't 'up the amperage' without doing some rewiring,

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I put the super-bold warning in, because it sounds like maybe you don't have much experience with power work.  Apologies if I misunderstood.

Anyhoo, as you say a good solution might be to run one of your mining rigs elsewhere, like in the garage or another room.

Desktop backups in series is a really bad idea.  Each one of them introduces another inefficiency, so you're drawing MORE power from the wall every time you add in another one.

I think you'll find that most units won't even WORK in series -- all the batteries are likely to start discharging at once.  Something about rectified square waves vs. sine waves, etc.  Not an engineer, don't even play one on TV.

Definitely check the BIOS for onboard / discrete GPU setting as well.

Sounds like maybe you have a laptop with two GPUs, probably an Intel and an ATI.  I'm guessing Lenovo?

Anyhoo, see if you can completely disable the Intel on-board GPU and use only the discrete one.

After that I'd probably reinstall Catalyst 11.4 and see if it detects your card properly.

If I've guessed wrong, apologies.  Also, take care you don't overheat your laptop / burn out the tiny tiny fan.

x1 PCIe is plenty, you will have no bottleneck on x8.

A lot of people are using cases with more spacing (or no case at all), so they can leave empty slots between the double-wide cards.

Have you manually ramped that hot card to 100% fan?  It's noisy, but it might help you out.  You can also clock it differently than your other two, and spend that juice/cooling on bumping the cooler ones.

I'd imagine a good balance would be where all three temps even out at a level you're comfortable with.

Worst night EVAR to be manning that phone line.

> sit your computer outside your bathroom or something and then it can heat that up

I think you'd rapidly find that a 1500w load would turn a bathroom into a sauna.  Plus, you know, all that moisture.

You've got it, that middle card can't breathe.  If the different cards have different types of blowers, might be worth switching up the order.

I recommend just extracting the signature from a more overclockable variant.

Definitely RBE + AMDOverdriveCTRL, should be able to hit 300 Mhash/s for each 5830 you have as long as your cooling is good.

Yeah, this sounds just about right.  In theory if you supply more voltage this card should be able to hit 1200 core, if you can cool it   I'm thinking about taking one of my cards out of the production rig and seeing just how far I can push it.  350 Mhash/s seems just -barely- doable, but would be horrendous for juice and cooling.

I'm also using 2.1 and poclbm, haven't had enough time to play with the latest miner/SDK combos under Ubuntu.

That's a 6970_M_ (high end mobile part) in a very restricted-airflow case.  I would heartily second your recommendation of NOT mining with one of these.

I can attest that 5830's seem to BEG you to overclock them.  A little RBE work and I've pushed mine as high as 320 Mhash/s stable.

That's the one, thanks pokermon

If your PCIe slots will let you, increase the gap between your cards.

Get one of those adjacent PCI slot blowers and stick it next to the hot one.

If your case will let you, add some more intake and/or outflow fans to increase the airflow to all your cards.

Run your case with the side off and point a directional fan at the hotspot.

Put your case in front of your air conditioner (NOT swamp cooler).

Those are the easy options; they all have different costs associated with them, so caveat emptor et cetera.

Use one of the overclocking tools that allow you to control fan speed manually, ramp it up until you find a stable temp you're comfortable with.

Should be able to squeeze 280 Mhash out of a 5830 pretty easily, I've had mine as high as 320 in testing.

Have you done the pinout mod on the PCIe extenders?  Poke around the forums, something about voltage you need to bump up or short out or some such.  Can't recall exactly, I'm not using ribbons myself.