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Topic: USB Risers problems (Read 2766 times)

newbie
Activity: 30
Merit: 0
July 14, 2016, 12:58:39 PM
#33
gpushack has good risers and they ship fast.
How did I never see that before?  AWESOME - thanks!

P.S. Here's a link:  http://gpushack.com/search?type=product&q=riser
hero member
Activity: 835
Merit: 1000
There is NO Freedom without Privacy
July 14, 2016, 04:59:08 AM
#32
gpushack has good risers and they ship fast.
sr. member
Activity: 445
Merit: 255
July 14, 2016, 03:41:41 AM
#31
Sorry I expressed myself poorly. How many GPUs will a pro BTC be able to feed off the motherboard itself without powered risers, just with ribbon cable risers? In my rigs I have 6 cards, totalling 8 Tahiti GPUs. That seem a lot of power for just the 2 molex on the ProBTC board.  

each molex can provide 132 watt, so you have 264w, plus the motherboard can provide 25w for each x1 slot and 75w for the single x16 slot, so a total of 200w

464w in total can be provided by the motherboard, it's more than enough for any 6 x card setup, minus those 2xchip gpu, like 7990

One power cable from the PSU will have 3 to 4 molex connectors, does it mean each cable can provide up to 500W?

Absolutely not. You will burn them, without a good OCP protection on the +12V from the PSU. If you've got a good OCP instead, on the female molex and sata connectors, the PSU will simply shut down. Be careful on the power delivery, it's thr MAIN source of issues
hero member
Activity: 1008
Merit: 1000
July 13, 2016, 09:47:25 PM
#30
I took a look at my riser that had issues to see if there was anything I could fix on it.

I found one of the pins on the back had a thin solder bridge shorting it out or getting one the data connections messed up during an opencl call, so I scratched it with my knife and seems to working properly now.  Simple fix but it caused me a lot of headache
hero member
Activity: 687
Merit: 511
July 13, 2016, 03:35:49 PM
#29
I've never seen a riser like those before...those look really interesting.  Anyone know of an online vendor selling these?

Technically, wouldn't padrino technically be an online vendor?  I've bought stuff from him before and he's great to work with.

I haven't looked to carefully into the spec, but I know that with the risers using the Molex connector, they're definitely using both the 5v and the 12v power supplied - whereas this riser would only be providing 12v from the PCI-e connector, so presumably drawing 5v across the ribbon cable.  

On my 6 card systems, each card generally draws about 1a at 5v across the riser molex connector... That's what steered me away from these solution combined with the fact it doesn't have mounting points, although I loved the fact they use PCI-e cables as that's a big hassle for my configurations.
sr. member
Activity: 377
Merit: 250
Next Generation Antivirus
July 13, 2016, 02:34:02 PM
#28
I purchased a few of these risers with the 6 pin PCIe power connectors so I could use them with my server power supplies.  They've been working pretty well for me so far.

https://bitcointalksearch.org/topic/wts-powered-risers-pcie-6-pin-molex-6-pin-to-8-pin-pcie-1418963
I've never seen a riser like those before...those look really interesting.  Anyone know of an online vendor selling these?
you can do it yourself
its not so hard? or buy in aliexpress
newbie
Activity: 30
Merit: 0
July 13, 2016, 02:08:50 PM
#27
I purchased a few of these risers with the 6 pin PCIe power connectors so I could use them with my server power supplies.  They've been working pretty well for me so far.

https://bitcointalksearch.org/topic/wts-powered-risers-pcie-6-pin-molex-6-pin-to-8-pin-pcie-1418963
I've never seen a riser like those before...those look really interesting.  Anyone know of an online vendor selling these?
hero member
Activity: 1008
Merit: 1000
July 13, 2016, 12:08:06 AM
#26
Had a experience with a bad riser thats a bit more "unusual"

Got another gpu to finish off this small rig from newegg and at first all went well.  But after a bit of mining the new gpu would fail the opencl call and crash and id reboot start mining again and the same thing after about 30mins-1hr.  I figured it was a faulty gpu so I sent it back and got a replacement but of course I thought about it and should have tested the damned riser.  I should also mention that if I would plug the gpu via the riser that to the main x16 slot on the mobo that it would fail to boot and hang.

So today I got my new gpu and I got it all set up and mining away, seemed the problem was fixed and I chopped it up to a bad gpu as I thought at first.  After 8 hours of mining the new gpu crashed and the miner restarted crashed again with 40 mins.  So then I swapped out my riser with a good one, in the gpu next to it and it booted normal and seems to be working as it should.

So the point of this story is that these damn risers and electronics in general can have problems where they do not fail completely.  I have wasted a good amount of time trouble shooting it, sending the gpu back and now I need a new riser to mine on the gpu.  So if you have a problem like this that doesn't seem to add up, suspect the riser!
hero member
Activity: 532
Merit: 500
July 04, 2016, 05:20:52 AM
#25
I am also interested for  a durable riser, many thanks.


Posted From bitcointalk.org Android App

You will need a USB riser with connection of the +12V both to the PCIE +12 V slots and the PSU +12V.
member
Activity: 76
Merit: 10
July 03, 2016, 06:29:12 PM
#24
I am also interested for  a durable riser, many thanks.


Posted From bitcointalk.org Android App
legendary
Activity: 1096
Merit: 1021
July 03, 2016, 10:53:02 AM
#23
I purchased a few of these risers with the 6 pin PCIe power connectors so I could use them with my server power supplies.  They've been working pretty well for me so far.

https://bitcointalksearch.org/topic/wts-powered-risers-pcie-6-pin-molex-6-pin-to-8-pin-pcie-1418963
hero member
Activity: 532
Merit: 500
July 03, 2016, 02:50:02 AM
#22
None USB risers can hold more then 40W!!! (that I know) the problem is USB cable, sata power adapter, etc too match resistance!

Just buy quality 1x to 16x riser with molex connector!
USB 3.0 cable should be able to provide 100W. But sata power is only 3x1,5 (3pins)=4,5A/12V= 54W.
So USB risers for RX480 should be powered via Molex, not via Molex-Sata adapter.

You can also use the old ribbon cables with the +12V molex connected to the +12 of the PCIE extension lead.
full member
Activity: 810
Merit: 101
July 02, 2016, 05:38:03 PM
#21
None USB risers can hold more then 40W!!! (that I know) the problem is USB cable, sata power adapter, etc too match resistance!

Just buy quality 1x to 16x riser with molex connector!
USB 3.0 cable should be able to provide 100W. But sata power is only 3x1,5 (3pins)=4,5A/12V= 54W.
So USB risers for RX480 should be powered via Molex, not via Molex-Sata adapter.
newbie
Activity: 36
Merit: 0
July 02, 2016, 04:23:55 PM
#20
Ok thanks for that, can you provide a link for a reliable vendor of those?
legendary
Activity: 1901
Merit: 1024
July 02, 2016, 03:54:59 PM
#19
None USB risers can hold more then 40W!!! (that I know) the problem is USB cable, sata power adapter, etc too match resistance!

Just buy quality 1x to 16x riser with molex connector!
newbie
Activity: 36
Merit: 0
July 02, 2016, 10:16:29 AM
#18

Thanks but I would like to stick with powered USB ones. Anybody with a source of reliable ones?
legendary
Activity: 3248
Merit: 1070
July 02, 2016, 07:53:26 AM
#17
there are some bad risers at ebay and some good, shame you can not know till you receive it

Is there nobody here who can point me to their source online for reliable risers?

bought a bunch from this guy, all working perfectly http://www.ebay.co.uk/itm/NEU-25cm-Extender-Riser-Flex-Kabel-PCI-E-PCIe-x16-Karte-x1-Slot-Cable-/291076040426?hash=item43c57be6ea:g:tu8AAOxyiRlSbV2F

he rised the price, it was much less before
newbie
Activity: 36
Merit: 0
July 02, 2016, 07:43:36 AM
#16
there are some bad risers at ebay and some good, shame you can not know till you receive it

Is there nobody here who can point me to their source online for reliable risers?
full member
Activity: 226
Merit: 100
July 02, 2016, 04:59:05 AM
#15
there are some bad risers at ebay and some good, shame you can not know till you receive it

also 7xx 2xx cards most draw little current from PCI-e slot (5-20w) but 3xx series some draw a lot more so bad riser will melt, even good riser I would not hold more of 60W a bad one might fall even on 30-40w or less

I think most or all the risers will not melt at 60W. 60W is just 5A, it most wires can withstand that. It is the PCIE slot, that is the problem.
legendary
Activity: 1901
Merit: 1024
July 01, 2016, 06:58:37 PM
#14
there are some bad risers at ebay and some good, shame you can not know till you receive it

also 7xx 2xx cards most draw little current from PCI-e slot (5-20w) but 3xx series some draw a lot more so bad riser will melt, even good riser I would not hold more of 60W a bad one might fall even on 30-40w or less
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