bitcoin mining quad xfire 5850 - need help picking mobo, case, psu

[joshuaMachine]

I'm getting a PC, and I figured I might as well try do some bitcoin mining just to subsidize the cost of the computer.

I didn't really care about AMD vs Nvidia but I figure I might as well go AMD graphics since it will be cheaper, factoring in some bitcoin mining.

I'm thinking about going quad xfire 5850. I need help selecting a motherboard / PSU / case that can support this.

Please help! Thanks! Cheaper is better!

I can pick the processor once I have a working mobo/psu/case option. I don't care what it looks like, I don't need anything fancy on the mobo or case except that it needs to support and fit 4x5850.

[cartman]

Hi,

I also want to build a machine employing 4 5850 GPUs. I thought about the following:

MSI 790FX-GD70
4x SAPPHIRE HD5850 Extreme
AMD Sempron 140
Kingston ValueRAM DIMM 1 GB DDR3-1066
OCZ Fatal1ty 750W

This is of course different to your specs since mine is going to be a dedicated miner. Still the mainboard and PSU might fit your needs.

Maybe some of the miner/hardware gurus of the board can share their thoughts on our plans. I am not so sure whether 750W is enough, especially when overclocking the cards! Any advice appreciated!

[chungenhung]

You might want to verify that those cards will be able to cool themselves directly next to each other. I've only had luck doing this with reference cards. I've had to place non-reference cards in the furthest spot from the CPU because they hit 80+ temps when jammed next to another card.

GPUs can reach 100C with no problems.
I've had 9800GX2 reaching 105-109C and still runs without errors.

[chungenhung]

Hi,

I also want to build a machine employing 4 5850 GPUs. I thought about the following:

MSI 790FX-GD70
4x SAPPHIRE HD5850 Extreme
AMD Sempron 140
Kingston ValueRAM DIMM 1 GB DDR3-1066
OCZ Fatal1ty 750W

This is of course different to your specs since mine is going to be a dedicated miner. Still the mainboard and PSU might fit your needs.

Maybe some of the miner/hardware gurus of the board can share their thoughts on our plans. I am not so sure whether 750W is enough, especially when overclocking the cards! Any advice appreciated!

Note that you cannot increase voltage on that sapphire 5850 card, thus limiting your OC potential. Mine max out at 830 core.

[fornit]

Hi,

I also want to build a machine employing 4 5850 GPUs. I thought about the following:

MSI 790FX-GD70
4x SAPPHIRE HD5850 Extreme
AMD Sempron 140
Kingston ValueRAM DIMM 1 GB DDR3-1066
OCZ Fatal1ty 750W

This is of course different to your specs since mine is going to be a dedicated miner. Still the mainboard and PSU might fit your needs.

Maybe some of the miner/hardware gurus of the board can share their thoughts on our plans. I am not so sure whether 750W is enough, especially when overclocking the cards! Any advice appreciated!

i basically just ordered the exact same rig.  only difference is 2gb ram and a 1kw sunflower gold plus psu.
if everything goes according to plan, i can tell you how its working this weekend.

[cartman]

thanks for the useful comments!

@fornit: curios about your experience, would be nice if you report! maybe i cant wait until weekend, difficulty to generate probably rises rapidly in the next days/weeks and i am just too excited

i wouldn't care about the 100C as long as the cards work fo a year minimum.

@chungenhung: can you recommend any other 5850 card which is more suitable for overclocking?

[ataranlen]

Running anything at 100% no matter the temperatures will shorten the life of the hardware, and the hotter it runs, the less life you can expect. Of course most hardware is expected to run 50k hours or so, but still.

[joshuaMachine]

what about the case? I presume it needs 8 slots? Any recommendations on something good on a budget?

[keybaud]

If the 5850 is a 2 slot card, like the 5870, you'll want 3 slots for decent cooling, so you'll need a custom made rig. Also, you don't want or need crossfire, but you will need to do the HDMI mod to tell the OS that you have cards that don't have a monitor attached.

/edit Just saw that your not building it as a mining rig, so you will want to crossfire the cards for gaming.

[Convery]

I got my Sapphire 5850 Toxic 1GB clocked 950/300 and that's pushing 363MHash/s and never goes above 60C (60% fan).

Even though it said that it couldn't adjust voltages I pushed it up slightly to 1.15 so the card became stable above 925 core.

I will however get two 5850 Extreme and see what I can do with it :3

[chungenhung]

I got my Sapphire 5850 Toxic 1GB clocked 950/300 and that's pushing 363MHash/s and never goes above 60C (60% fan).

Even though it said that it couldn't adjust voltages I pushed it up slightly to 1.15 so the card became stable above 925 core.

If it couldn't adjust voltages, then how did you push it up to 1.15??

[Vwlopez3]

If the 5850 is a 2 slot card, like the 5870, you'll want 3 slots for decent cooling, so you'll need a custom made rig. Also, you don't want or need crossfire, but you will need to do the HDMI mod to tell the OS that you have cards that don't have a monitor attached.

/edit Just saw that your not building it as a mining rig, so you will want to crossfire the cards for gaming.

Sorry whats the HDMI mod you were talking about? I would like to be able to diable monitors and not worry about them shutting down mining. Thanks
Thomas

[keybaud]

If the 5850 is a 2 slot card, like the 5870, you'll want 3 slots for decent cooling, so you'll need a custom made rig. Also, you don't want or need crossfire, but you will need to do the HDMI mod to tell the OS that you have cards that don't have a monitor attached.

/edit Just saw that your not building it as a mining rig, so you will want to crossfire the cards for gaming.

Sorry whats the HDMI mod you were talking about? I would like to be able to diable monitors and not worry about them shutting down mining. Thanks
Thomas

You need to put a resistive shunt across some of the HDMI channels so it lies to the PC and says there's a monitor connected:

http://bitcointalk.org/index.php?topic=6575.0

[Vwlopez3]

thanks

[bernd]

I got my Sapphire 5850 Toxic 1GB clocked 950/300 and that's pushing 363MHash/s and never goes above 60C (60% fan).

Even though it said that it couldn't adjust voltages I pushed it up slightly to 1.15 so the card became stable above 925 core.

If it couldn't adjust voltages, then how did you push it up to 1.15??

I am interested in that as well. When i try to change the Voltage Settings with RBE, it says there is only one fixed Voltage, 1,088 V.