Old motherboards?

[mitm19]

Hello
 I recently got a 5830 working in an old P4 Intel motherboard, I had quite a bit of trouble getting it working. I had a 550 watt power supply driving only the board, memory, CPU, three fans (including the CPU fan) and the video card. Its booting off of a USB stick, and there is nothing else attached. Every time I would try to start hashing, the machine would shut down, finally I was able to get it working by just jumpering another 300 watt power supply on and attaching it to the video card only. I didn't measure the draw of the power supply driving the board / cpu but I did measure the one driving only the card, and it was ~225 watts.

Its been stable for several days at this point, but can't be overclocked (I'm thinking due to power for some reason) and only is hashing at 250Mhash. Any ideas as to why? I'm guessing that the main power supply isn't really able to put out 550 watts, and maybe since its an older PCIE 1/0 slot it isn't putting out enough power through the slot? I had to give back the Kill-a-watt that I was using to measure, so I can't check that now.

Any suggestions would be appreciated, I was going to try to get another card working in the x1 slot that is also on the board, but I'm having second thoughts on that.

Thanks

[hmblm1245]

whats the model of the 550?

The older p4 systems did draw a lot of power compared to today's systems but for it to ask for 275 seems a bit high. Most p4 systems are in the 150 range over clocked and that's pushing it. i would guess that your 550 is not putting enough power per rail for the two pcie connections. i have a neo 550 pushing a 1100t msi board with 5 case fans and two 5850s oced to about 950/500. No issues. It it depends on the psu.

The PCIE 1x should not matter at all.

[mitm19]

Thank you for the reply, the power supply that is driving the board is this :

http://www.newegg.com/Product/Product.aspx?Item=N82E16817162020

For sure it is junk, but the original power supply that ran that board in a half height case was only 165 watt, and that ran fine. Seems like the 5830 needs a lot of power in this board, and I don't know why. I have another machine with an AM3 Sempron and a 5830, and the whole box only uses ~210 watts according to the Kill-a-watt. This machine is using 265-275 watts for only the video card, and the 550 is running just the board / ram / cpu and fans.

I suppose I could just buy a decent power supply.

[hmblm1245]

I had issues like this before. the kill a watt is measuring the draw between the wall and the power supply. If the the psu is not efficient it may be pulling more then the older 165 just because it it thinks it needs it. The 5830 is a power hungry beast but a decent 550 should power that system without issues. i would rma it (if you can). it may be that one of the caps blew inside but it is still working just not when you push it.

[DrZaius]

It's definitely the junk power supply that's the problem.

The older p4 systems did draw a lot of power compared to today's systems but for it to ask for 275 seems a bit high. Most p4 systems are in the 150 range over clocked and that's pushing it.

150? Yeah...if it's idling!

If it's a Prescott P4 then I would say undoubtedly 275 is about right:

https://i.imgur.com/0BONV.gif

That's with a OCZ PowerStream PSU. An inefficient $20 PSU powering a 5830 running at 100%? 275 sounds right.

[mitm19]

Hmm, that is interesting stuff for sure. The power supply that is hitting 275 watts is not the one driving the board though, nor is it the 550 watt rated one. The 550 watt rated power supply would just shut down when I attempted to start the GPU hashing when it was the only one running the motherboard and the GPU, so I took another older 300 watt rated power supply and jumpered it to start when I turn it on, and connected it to *only* the GPU. The $20 Okia power supply is connected to only the motherboard and the fans. The 300 watt rated power supply runs steady at ~275 watts according to the Kill-a-watt, I didn't actually measure what the Okia is running at. Its all just a bunch of junk, really, but it is working I guess. What I found most interesting is that *just* the GPU runs at ~275 watts in this setup, but the exact same GPU in a modern AM3 board runs at ~200 watts for the entire machine, including the board / cpu / ram. Thanks for the info.

[Artamir]

Shoing 275 Watt and showing 275 Watt isn't the same, with 2 different PSUs.

If its efficiency is 50% that means the GPU is pulling 137,5 Watt, but your PSU consumes 275 Watt, the difference is mainly going into heat.

If your PSU on the other hand has an efficiency of 80% hen your GPU is pulling 220 Watt.

So the Kill-a-Watt only shows you what bill you are going to expect, not how much the components are eating up.

[JimTaylor]

Shoing 275 Watt and showing 275 Watt isn't the same, with 2 different PSUs.

If its efficiency is 50% that means the GPU is pulling 137,5 Watt, but your PSU consumes 275 Watt, the difference is mainly going into heat.

If your PSU on the other hand has an efficiency of 80% hen your GPU is pulling 220 Watt.

So the Kill-a-Watt only shows you what bill you are going to expect, not how much the components are eating up.

In the end, the bill is what matters though when it comes to mining, electricity doesn't grow on trees.

[mykroft]

I had issues like this before. the kill a watt is measuring the draw between the wall and the power supply. If the the psu is not efficient it may be pulling more then the older 165 just because it it thinks it needs it. The 5830 is a power hungry beast but a decent 550 should power that system without issues. i would rma it (if you can). it may be that one of the caps blew inside but it is still working just not when you push it.

FWIW, I couldn't get any of my 5830's to run unless I had at least a 600W PSU.  Even more if I was running two in the same mobo.

[critmass]

Related question: does it matter what kind of motherboard you are using, and if so, how much?  (I figure a noob question like that is perfectly acceptable on a newbie board)

[mitm19]

Yea I was wondering that as well, if the motherboard was somehow unable to supply enough power from the slot to the card so it was making up the difference in some strange way. That does make good sense about the inefficiency of the power supply though, the GPU must be using whatever it needs to use, and then the rest of the power must be being wasted. That box is still totally stable and hashing away with no trouble at all though, so that is good anyway. Thanks

[vapourminer]

my dedicated rig is a hp/compaq dc710.. P4 prescott 2.8. 40 gig hdd, 2x 1 gig ram, no opticals.

with an antec basiq 500 psu powering everything, killowatt says 321 watts. thats 20% cpu load, 1050/354 clocks on the 5830 and it mining .

before the basiq psu I ran it on the stock hp/compaq 350 psu with the card @ 850/354, killowatt said 340 watts mining. cant remember idle draw. only did that for a few weeks though.

with the basiq, idle the rig draws 120 watts or so.

just tossing the numbers out as I have a similar setup as the OP. btw the basiq is NOT an 80+ psu.

[mute20]

Your power supply is simply a piece of shit. You get exactly what you pay for so cheaping out on a power supply is not worth it as the listed wattage is not what the power supply is going to do.  I doubt it even pumps out more than 400w. Your poor performance would also be related to this as the card is not fully powered.

[phantomcircuit]

That P4 is going to burn through any profits you're seeing...