hasn't someone somewhere posted an easy definitive guide on how to build a multi-GPU rig? 
Topic: Litecoin: 1x to 16x PCI-E extenders, CPU question (Read 7704 times)
I am confused.com hasn't someone somewhere posted an easy definitive guide on how to build a multi-GPU rig?
hasn't someone somewhere posted an easy definitive guide on how to build a multi-GPU rig? 
you should be able to get 6 cards in that puppy. Just fine tune the settings so all the cards are running good together, you may have to tune back each one a bit, but your overall is higher. Make sure ya have the power too.
Something weird is going on.. ive attached 6x 7950 (using powered risers) to the 990FXA-GD65. Rig installed with Ubuntu.
When i boot it up and list devs, it only shows 2 devs..
Any idea?
By the way, do you mind do link the device you are using to have more pcie's ?
you should be able to get 6 cards in that puppy. Just fine tune the settings so all the cards are running good together, you may have to tune back each one a bit, but your overall is higher. Make sure ya have the power too.
I just got some minipcie to pcie16, no issues what so ever, now I can get double the cards per rig!
I can confirm that the 990FXA-GD65 needs the presence mod on all PCI-e slots, yes.
What do you mean by mod ?
To shortpin or..?
Also do you think it's a better idea to get a CPU/mobo with integrated graphics, or is it okay to use one of the mining GPUs for video? (this would be a dedicated mining rig... it would just be sitting there with a terminal running cgminer)
For my latest build I picked up an AMD APU to power the monitor instead of off the gpu or integrated graphics. $43 for the APU, just needs to be set as default display in BIOS. The only problem with this is you are more limited with the mobos available, most only have 2 pci x16 because of the APU slot, but mine also has 3 PCI x1 slots.
Best mobo for APU is ASRock A55DEL 5 x PCI-E for under $70
And btw You don't have to use powered risers even for 6 GPUs if your mobo has power port next to PCI-E (6PIN usually. I have MSI 990FXA-GD65 with 6 GPUs, no problems at all.
a couple of questions :
1. do you run CGminer?
2. what do they all hash ?
i'd love to see a screen shot with 6 running ?
no noticeable performance decrease unless your rig is underpowered. no need to worry about the cpu, cheapest is fine, youll be using the gpu.
not exactly accurate - your cpu will need to support the Pcie lanes for the cards, so if you run multiple cards your cpu (while not having to be high end ) has to support the Pcie channels .
if you are going to try to run more than 4 cards , better to get powered risers .
but you can get away without - don’t skimp on the PSU. - Everyone comes back and say "I wish i had of...."
no noticeable performance decrease unless your rig is underpowered. no need to worry about the cpu, cheapest is fine, youll be using the gpu.
Yup spend the money on the GPU and the extra 100 for a rock solid PSU. Go with PCpower and cooling, or heck corsair and seasonic.... just because it say 1100w on the sticker dont mean its high quality.
Also, try to make it a single rail PSU. Not as critical as some people would have you believe, but if it is a multi rail PSU you have to pay attention to how you balance your loads. I overloaded a rail one time on a multi-rail PSU and the thing died really quick. Luckily no other hardware was damaged.
what is this railing stuff?
I can confirm that the 990FXA-GD65 needs the presence mod on all PCI-e slots, yes.
thank you
I can confirm that the 990FXA-GD65 needs the presence mod on all PCI-e slots, yes.
...
And btw You don't have to use powered risers even for 6 GPUs if your mobo has power port next to PCI-E (6PIN usually. I have MSI 990FXA-GD65 with 6 GPUs, no problems at all.
http://pl.msi.com/pic/product/five_pictures1_2401_20110531112823.jpg
And btw You don't have to use powered risers even for 6 GPUs if your mobo has power port next to PCI-E (6PIN usually. I have MSI 990FXA-GD65 with 6 GPUs, no problems at all.
http://pl.msi.com/pic/product/five_pictures1_2401_20110531112823.jpg
does this MSI 990FXA-GD65 require shorting pin A1 B17 for pci-e 1x to work?
I have problem with 1x extenders on MSI 990XA-GD55 and I am thinking about changing it for this 990FXA-GD65.
Also do you think it's a better idea to get a CPU/mobo with integrated graphics, or is it okay to use one of the mining GPUs for video? (this would be a dedicated mining rig... it would just be sitting there with a terminal running cgminer)
For my latest build I picked up an AMD APU to power the monitor instead of off the gpu or integrated graphics. $43 for the APU, just needs to be set as default display in BIOS. The only problem with this is you are more limited with the mobos available, most only have 2 pci x16 because of the APU slot, but mine also has 3 PCI x1 slots.
Best mobo for APU is ASRock A55DEL 5 x PCI-E for under $70
http://pl.msi.com/pic/product/five_pictures1_2401_20110531112823.jpg
I've heard of a lot of problems with asrock, I try to avoid them. I got lucky and got an open box deal on a gigabyte FM1 socket for $65. But no 6 pin. http://www.newegg.ca/Product/Product.aspx?Item=N82E16813128515
I will going up to 5 cards on my Gigabyte 990fx-UD5 (it doesn't have a 6pin connector like that MSI board, *nifty*)
I've read that 6 pin connectors will supply 75w while the 6+2 pin connectors will supply125w for a total of 225 watts to the card. I'm using gigabyte 9750's.. I read on the AMD site that they draw 200W a piece.
Why would I need powered risers when a LEPA G 1600w PSU will be in place? That's enough power for 5 cards and 300w to spare.
I've read that 6 pin connectors will supply 75w while the 6+2 pin connectors will supply125w for a total of 225 watts to the card. I'm using gigabyte 9750's.. I read on the AMD site that they draw 200W a piece.
Why would I need powered risers when a LEPA G 1600w PSU will be in place? That's enough power for 5 cards and 300w to spare.
Also do you think it's a better idea to get a CPU/mobo with integrated graphics, or is it okay to use one of the mining GPUs for video? (this would be a dedicated mining rig... it would just be sitting there with a terminal running cgminer)
For my latest build I picked up an AMD APU to power the monitor instead of off the gpu or integrated graphics. $43 for the APU, just needs to be set as default display in BIOS. The only problem with this is you are more limited with the mobos available, most only have 2 pci x16 because of the APU slot, but mine also has 3 PCI x1 slots.
Best mobo for APU is ASRock A55DEL 5 x PCI-E for under $70
And btw You don't have to use powered risers even for 6 GPUs if your mobo has power port next to PCI-E (6PIN usually. I have MSI 990FXA-GD65 with 6 GPUs, no problems at all.
Also do you think it's a better idea to get a CPU/mobo with integrated graphics, or is it okay to use one of the mining GPUs for video? (this would be a dedicated mining rig... it would just be sitting there with a terminal running cgminer)
For my latest build I picked up an AMD APU to power the monitor instead of off the gpu or integrated graphics. $43 for the APU, just needs to be set as default display in BIOS. The only problem with this is you are more limited with the mobos available, most only have 2 pci x16 because of the APU slot, but mine also has 3 PCI x1 slots.
So basically:
1. I'm fine with unpowered if I'm plugging into full sized connectors (16x, 8x, 4x)
Or
2. If there's a separate molex connector for the 1x slots
But if not, I need a powered riser?
(Is the above all correct?)
I have a friend who set up a ltc rig with unpowered connectors and we were getting all kinds of cgminer errors with ltc but not with btc... this might explain the mystery.
This is all very useful info; I think I'm going to try an asrock board with either enough full-sized slots or with the extra molex connectors based on all the info above.
1. I'm fine with unpowered if I'm plugging into full sized connectors (16x, 8x, 4x)
Or
2. If there's a separate molex connector for the 1x slots
But if not, I need a powered riser?
(Is the above all correct?)
I have a friend who set up a ltc rig with unpowered connectors and we were getting all kinds of cgminer errors with ltc but not with btc... this might explain the mystery.
This is all very useful info; I think I'm going to try an asrock board with either enough full-sized slots or with the extra molex connectors based on all the info above.
Sounds great... now one more question; do you need powered 1x to 16x risers?
I have a bitcoin rig with 2 unpowered 1x to 16x risers for 5830s and they run fine but I see some people saying you need powered risers.
I have a bitcoin rig with 2 unpowered 1x to 16x risers for 5830s and they run fine but I see some people saying you need powered risers.
I would definitely go for powered.
Here a link to a post I made where I caught my mobo on fire:
https://bitcointalksearch.org/topic/bamt-05c-cgminer-261-litecoins-motherboard-burst-into-flames-161242
TLDR : The likely cause seemed to be unpowered risers and incorrect cgminer settings.
That being said I do still have that rig running the 4 cards without powered risers without further issue. I just got lazy and left cgminer at the original settings I tried.
Hi,
Not sure if this helps but I have my first rig, it is an old ex corporate machine with a AMD 64 3500 cpu (v.slow), however the mobo has 2 pci e slots. A 1x slot and a 16x slot, due to space I will be using both on risers, atm I just have a 7850 in and that is running off the 1x and I am pulling 350kh/s (btw I have a cool master 650 watt 80% rated PSU and I have pulled out the original 280watt).
I am just waiting on my second card now which will be making it's way into use next week.
The only big issue I have is placement of the cards. Luckily I have access to a 3D printer so once the 2nd card comes I will be measuring up both cards to make something stable but airy.
Not sure if this helps but I have my first rig, it is an old ex corporate machine with a AMD 64 3500 cpu (v.slow), however the mobo has 2 pci e slots. A 1x slot and a 16x slot, due to space I will be using both on risers, atm I just have a 7850 in and that is running off the 1x and I am pulling 350kh/s (btw I have a cool master 650 watt 80% rated PSU and I have pulled out the original 280watt).
I am just waiting on my second card now which will be making it's way into use next week.
The only big issue I have is placement of the cards. Luckily I have access to a 3D printer so once the 2nd card comes I will be measuring up both cards to make something stable but airy.
This is from memory so it's probably wrong.
x16 spec is 75 watts
x1 spec is 25 watts
You run the risk of pulling too much current through the 25 watt connector, which results in problems under several possible conditions:
1) The GPU prefers PCI power over 6+2pin connector power
2) The PSU or MoBo cannot handle the full load from the PCI-E connectors combined, when over-loaded
3) The x1 connector's traces were slimmed down to only support 25 Watts
There's also this mobo which comes with a 12 V molex right by the slot for extra power:
www.newegg.com/Product/Product.aspx?Item=N82E16813157339
The asrock boards have nice power/reset buttons built into them (most of them) which is nice if you're going caseless and don't wanna bring out the screwdriver and start jabbing pins on the header.
x16 spec is 75 watts
x1 spec is 25 watts
You run the risk of pulling too much current through the 25 watt connector, which results in problems under several possible conditions:
1) The GPU prefers PCI power over 6+2pin connector power
2) The PSU or MoBo cannot handle the full load from the PCI-E connectors combined, when over-loaded
3) The x1 connector's traces were slimmed down to only support 25 Watts
There's also this mobo which comes with a 12 V molex right by the slot for extra power:
www.newegg.com/Product/Product.aspx?Item=N82E16813157339
The asrock boards have nice power/reset buttons built into them (most of them) which is nice if you're going caseless and don't wanna bring out the screwdriver and start jabbing pins on the header.
Burn that shit to the ground. Go LTC.
Hahaha well my plan is to build one rig and get a feel for ltc mining, work out the kinks in the system, etc., and then see if anyone is interested in investing in a small hosted mining setup and ideally building a few more rigs and hosting them for a small fee. Not going to be a huge operation due to the power limitations of the house I live in and also because I don't really have much rep on these forums, but a good starting place especially with the craziness going on in the btc mining world right now.But of course I still need to actually build my first ltc rig. So yeah, I'll hopefully be burning that shit to the ground in a week or so.
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