Installing a second PSU in a desktop

[۩]

Hello, offtopic I know,

I just got a 500w psu to power my second gfx card.
I thought I could simply plug it in and it would be good to go :roll: I was wrong.

What do I have to do to get the PSU to turn on to power the second graphics card?

Thanks, in the mean time I will be scouring mostly unhelpful computer forums...

 

[a1pha]

So you have two PSUs in one computer? Why didn't you go for one 1000w? Any chance you can take it back and get one with a higher wattage? The only good use for 2 PSUs is for redundant supply of power.

 

[Carrierwave]

There is a ground in the motherboard connector that triggers the current flow. (probably the wrong words but hopefully the idea gets across, im not an electrician) I believe it in the 4th and 6th 'prong'. Use a paperclip to jump it. I will confirm in the next 5 minutes which 'prongs' they are so you don't make your PSU go boom.

 

[a1pha]

Use a paperclip to jump it.

LOL - Please remove all $400 graphic cards before jumping. I don't think it's covered under warranty.

:lol:

 

[MySmelf]

I have a PSU tester. Its basically just a switch with some LEDs for the voltages. It plugs into the motherboard connector, you could mount it soo the switch is on the outside of your case. I'm sure you could find one online.

 

[Carrierwave]

Ah 4/6th happens to be my particular power supply, not generalized to all.

http://www.overclock.net/faqs/96712-how-jump-start-power-supply-psu.html

There are nicer things to use than a paperclip, true. Haha.

 

[a1pha]

Oh House, that reminds me. You said you were having problems with freezing when bumping up to 320ish Mh/s? Remember to increase the voltage on the graphic cards and in BIOS if you can. You might even consider a new MB. I've been pleased with ASUS crosshair boards for overclocking.

EDIT: Such as this one. Supports up to three cards as well... :d

 

[۩]

OK so it's bridged and powered.

I now have 4 ports for a monitor in the back of the comp. When the second HD5850 is on, the computer automatically uses this card for displaying the monitor display so I have to switch the monitor cable.

What do I need to do next to get these to work? I tried mining while I wasnt overclocking and my computer just automatically restarted. There's definitely a next step that I am missing here...

 

[a1pha]

Have you enabled crossfire in the CCC?

Also, this sounds related.

BIOS update?

 

[۩]

Crossfire has been enabled, thanks for that Had to install the little connector piece, too.

I will now attempt to mine...if I fail, I will attempt to figure out a BIOS update ;D thanks yall

 

[a1pha]

Oh ya, you need the bridge on there. =D

GL! Going to be at ~700 Mh/s? Niiice.

I'm at 200 now. The 5700 wouldn't fit in my spare computer. Going to build a mining rig soon. Hehe.

 

[۩]

yep, whenever I try to mine from [0] cypress the psu just shuts off. At first I see a "error connecting to the btc server" in the miner then the screen goes black.

The comp is currently using the new card to display, and I can still mine on [1] cypress I just can't quite seem to figure out how to get them to cooperate.

 

[a1pha]

What's your configuration? Is there an on-board graphics card or by 'old card' do you mean the original 5850?

What model is the MB?

 

[۩]

I have an asus its like the one you linked and was about the same price I bought it fairly recently, It's blue. I know that's terrible information and I apologize. I only saw enough room for 2 of these in there, not three ;]
and yes Im running 2 x HD5850.

 

[۩]

Update: I'm looking at the CCC and I can see [1] cypress is actually the first hd5850 and that is mining at full capacity.

Looking at the new card in ccc it says Syncmaster. This is telling me the new card is indeed giving the monitor display and is working @ 0 %. OK so now we know what the cards are, and what they are doing.

Only problem is the damn PSU turning off when I try to mine from the new card. 'Tis a mystery

 

[a1pha]

Sometimes there's an onboard video card (not in one of the PCIx slots) that needs to be disabled in BIOS. This is unlikely but worth checking out.

Have you gone into BIOS much? If it's an ASUS MB with support for two ATIs I would bet there's some tweaking you need to do in there to get everything running well (increase voltages, clock speed, memory, etc.).

First I'd update BIOS, then install the latest CCC (not the software that came with the card), then I'd start messing with BIOS. Do you have another computer to chat on while playing with BIOS? Maybe I could walk you though...

 

[۩]

I wish I did have another computer. I am very unfamiliar with BIOS I've only used it a few times in the past. I know how to work my way around it I just don't know how to optimize this situation. I am going to do some research right now and try to figure that out.

 

[a1pha]

Ohh, this sounds like your problem... looks like this is a known issue.

The problem is ultimately in the 5xxx series cards being underpowered due to Powerplay downclocking and under volting to such a low level (in this case 157/300 @0.95) that errors not only would,.. but DID cause an unreasonable amount of instability issues.

http://forums.amd.com/forum/messageview.cfm?catid=203&threadid=123623

 

[۩]

I checked the BIOS and all the voltages I could see were on Auto. Does ^^ that mean I need to make some adjustments to them?

 

[a1pha]

Try increasing the voltages slowly until the problem goes away or nothing, in which case it's something else. This just seems the most logical from your description of the problem (and the fact that two ATI 5850s running together sucks a WHOLE LOT of juice from your machine). I think you need a minimum of 1k w for this - but again it's been awhile since my gaming rig days.