Cheap 5x R9 290 mining rig

[Pustul]

Hey guys,
I want to make a very cheap rig to fit my 5 R9 290 instead of using my two desktops cases which have good cpus and are primilary used for gaming

Here are the components:
Motherboard: Asrock FM2A55 PRO+      60$
CPU: AMD Athlon X2 340      40$
GPU: 5x Sapphire R9 290    
RAM: 2x Kingston ValueRAM 4GB DDR3 1600Mhz    85$
PSU: 2x Corsair RM850

1) I already have the GPUs and the PSUs so the rig will cost only 185$, but I'm not sure 2x 850W can handle 5x R9 290, it should right?
2) And what about the A55 chipset, I can't find information about this one, but since there are 5x pci-x slot it should handle the 5 GPUs, right?
3) Lastly is 8GB of system ram sufficient? I read elsewhere that it can cause trouble with high value of TC.
4) Bonus: Is there any cheap mb that can fit more than 5 GPUs? By cheap I mean less than 100$

Thanks for you help

[padrino]

Each card will pull around ~300W based on how you have them configured, if you undervolt them perhaps you can squeeze under the wire between that and balancing one on both PSUs.

[CryptoGeneral]

Do you think that the new Corsair PSU could be of any use for a serious rig?

[notlist3d]

Do you think that the new Corsair PSU could be of any use for a serious rig?

Yes but chances are price wise your better off with two PSU's. 

[mechtronic2001]

I currently run between 1500-1600watts with 3x290 overclocked. I believe I was sitting at around 1400watts previous to overclocking.
sempron 140
msi 890fx
8GB ram
300GB HD
3x R9 290
2x1000w psus

hope this helps!

[Wipeout2097]

Do you think that the new Corsair PSU could be of any use for a serious rig?

Yes but chances are price wise your better off with two PSU's. 

Yeah, listed $450 at Corsair website. Ouch!

[Pustul]

Thanks for your help, I've ordered the pieces

[CryptoGeneral]

Well, maybe we have to wait until competitors release their titanium PSUs. I guess price on those babies would drop a bit.

[Pustul]

I received everything but I struggle to get more than 3 gpu running... And even with 3 I have trouble. I tried everything windows 8, xubuntu, bamt, smos... Sometimes I get 4 and even 5 gpu recognized by windows or linux but the pc freezes after a few minutes :/

I don't know where it comes from, the pci-e usb riser, the mobo or the drivers... Sometimes the screen has flickers so I think maybe the problem is the 1x to 16x riser for the display, should I get 16x to 16x?

[pontiacg5]

Are you trying to mine at all, or is the system locking up with no load on the GPUs?

Two 850W power supplies are likely not enough to run 5 290's, but I don't think that's the only problem here.  

I also have no idea what the previous poster with 3 290's pulling 1600W is doing, but I run 5 on 1500W-1600W. Or, 1.8K out of the wall, roughly. And that is overclocked...



Ribbon riser cables are pieces of crap that have trouble working on a good day. Do not buy x16-x16 risers, there's simply 15 more lanes of connections to break and go bad. If you get anything new, make it USB riser cables.

[bmL]

I currently run between 1500-1600watts with 3x290 overclocked. I believe I was sitting at around 1400watts previous to overclocking.
sempron 140
msi 890fx
8GB ram
300GB HD
3x R9 290
2x1000w psus

hope this helps!

Your PSU must be very inefficient. 3x r9 290x on  original power/clocks etc. hashing 2.9 mh/s and consuming 1180 W at wall (it's 90% eff. PSU wchich means whole rig pulls no more than 1100W)

[kcobra]

I currently run between 1500-1600watts with 3x290 overclocked. I believe I was sitting at around 1400watts previous to overclocking.
sempron 140
msi 890fx
8GB ram
300GB HD
3x R9 290
2x1000w psus

hope this helps!

Your PSU must be very inefficient. 3x r9 290x on  original power/clocks etc. hashing 2.9 mh/s and consuming 1180 W at wall (it's 90% eff. PSU wchich means whole rig pulls no more than 1100W)

+1. Something way off with that guy's numbers. My 4.4ghz 3570k system with two 290's, not overclock, pull ~650w from the wall when mining. CPU is idle of course.

[Pustul]

Are you trying to mine at all, or is the system locking up with no load on the GPUs?

Two 850W power supplies are likely not enough to run 5 290's, but I don't think that's the only problem here.  

I also have no idea what the previous poster with 3 290's pulling 1600W is doing, but I run 5 on 1500W-1600W. Or, 1.8K out of the wall, roughly. And that is overclocked...

Ribbon riser cables are pieces of crap that have trouble working on a good day. Do not buy x16-x16 risers, there's simply 15 more lanes of connections to break and go bad. If you get anything new, make it USB riser cables.

Yeah I know 2x 850W is perhaps not enough but I can't even get the system running stable with no load and the 5 cards recognized.
I have 5 usb riser cables I'm just wondering if it's enough for the card to display correctly the screen because sometimes I have flickers... But I've been hashing a few hours on 3 gpu on windows flawlessly so maybe it's not that after all.

[Pustul]

I've got it working nicely with 4 gpu on windows 8.1.
One of my riser has problems and when I try to connect a gpu with it, it either produce flickering or isn't recognized by the mobo so I still don't know if 5 gpu is possible.

[Pustul]

I've got all 5 cards working without shorting pci-e slots using 4 usb risers and the fith gpu directly on the last 16x slot since my fifth riser is defective. Pretty good for a 60$ mobo.

Running stable for a few hours now, hope this will last

Consumption at stock voltages:
1st power supply: 830W
2nd power supply: 790W
Total: 1620W

Consumption undervolted with afterburner:
1st power supply: 780W
2nd power supply: 750W
Total: 1530W

Edit: After a few hours the consumption has increased:
Consumption undervolted with afterburner:
1st power supply: 780W
2nd power supply: 780W
Total: 1560W