Topic: Gauging interest around some custom hardware and cabling for GPU rigs - page 4. (Read 6160 times)

If you're going to do PWM, I'd suggest adding temperature-based speed control.  There's a i2c temperature sensor (LM75 I think it was) on the i2c bus (pins B5/C5).  I forget the address, but you can find it with an i2c scanner; it's the lowest address of 3 you'll find on the bus.  Never figured out what the other 2 devices, but the LM75 gives 2 temperature readings in Celcius, one of which is off the heatsink for the mosfets.  I made a circuit with an attiny13a for PWM fan control (pin B2 I think), varied by ADC reading from a POT.  My plan was to do a bit-bang i2c implementation to read the temperature and make the fan speed temperature dependent, but still haven't got around to it.

Initial testing on the Molex adapter board looks good. It's currently drawing about 18A off the 5V rail which is good since I intended to give it a 15A rating. A little airflow goes a long way too, just saying. Tomorrow I'll test how well it handles the heat of that much 5VDC conversion while drawing about 20A of 12V through the PCB.

I'm glad it's working well right off the bat. Maybe I'll put up pictures tomorrow.

Prototype PCBs for the Molex adapter have finally arrived. I'll be assembling and testing in the next few days and hopefully they work well and reliably.

I have already tested the new Dell 750W PSU board and it's in need of slight revision (including adding PWM fan control as suggested in this thread; it's been tested but not yet integrated), so I'll probably have another prototype PCB order going out soon. I intend to have a test version ATX24 adapter on that order - nothing fancy, directly powered with unswitched 12V EPS rail and probably two jacks for Molex cabling (compatible with the Molex adapter board, gotta love interchangeable parts).

I'm also playing around with a 1500W PSU that works with my edge-connector board (compatible with DPS800 and HP Common Slot family supplies), which might be interesting to some of y'all with six ~200W cards - depending on how all the jacks line out.

MarkAz is kinda the partner in crime for the cabling and adapter solutions so he'll probably have first access for actual in-rig testing. But that's okay because he likes posting pictures a lot more than I do and he's better at it anyway.

My mom knew well enough to understand early that racism and its ilk were foolish and raised us kids to think about people as people rather than targets. Subsequently I have more hangups about people who are fine with being lazy or dumb and not trying to do better for themselves than about any race or sexual preference. Considering the neighborhood, I feel lucky to have had the parents I did.

Fan control on the Dell 750 board is a basic pot. The DPS2K board (out of stock and pending some redesign) has adjustable PWM to two 4-pin headers for external fans. The DPS8/12 board doesn't have fan control because those supplies are internally regulated. Current measurement was done with a low shunt resistance and sense amplifier, but the feature was so little used compared to cost it's been removed.

I grew up in a rural area; knew how to shoot, drive a tractor, and handle a chainsaw by age 12.  However I find intolerance is far more pervasive in rural areas than urban.  It was nothing to hear nigger and paki jokes at school, and if you valued your life you didn't come out as gay until after you left town.  I didn't realize how bad it was until I moved away for university (and suddenly found out some of my friends were gay).

Anyway, sorry for sidetracking the thread.  Getting it back to the topic, do you just use a pot for fan control on your breakout boards, or do you have a PWM circuit?  For the current output monitor pin, did you just use a high-resistance voltage divider on the current share pin from the PSU?  When I tested with the n750p, the current share voltage seems close to linear at 1V=~100W.

I used to say I was proud to be from Missouri, but then I started learning more about other people in the Bitcoin world. BFL, VMC and MinerSource are all from Missouri; Minersource started in the same town I'm based in, even. Yes there are a lot of hicks in MO, and I did grow up on a farm, but if you know where to look you can find a lot of really smart people and if you really know where to look you can find smart hard-working people. Rural upbringing does wonders for the work ethic.

I may have ended up with a couple PSUs from you, since the first 2 750p's I bought were from Maxime.  I soon found a guy from Markham (Toronto suburb) selling them for ~C$20 ea, and that's where I got the rest of them.  I like the 1520AB the best, since I don't need to add a fan control circuit.  I know you can ground the fan speed control input (B2) for low fan speed, but they'll get pretty hot if you go over 50% load.  I tried a trim pot, which was too unstable to be useful (fan speeds would fluctuate up/down significantly).  It's a PWM digital input (not analog), so it's no surprise the trim pot doesn't work well.  The best solution I came up with was a AtTiny13A generating a PWM signal with the duty cycle varying according to the ADC input connected to a trim pot.  What I eventually plan to do is read the temperature of the output mosfet heatsink over the I2C bus, and vary the PWM output according to temperature.

Thanks for clearing up your connection to bitcoinware.  I searched around gekkoscience.com to find shipping info to see where you are located, but couldn't find any.
Now that you say you're from MO, I'm impressed.  The only person from there I know was a big redneck who wouldn't shut up about his son playing for ole miss.  I kinda wish Canada hadn't issued him a landed immigrant card...

I supplied a lot of PSUs to Maxime last year, before they started doing a lot of work in-house - both breakout boards and hard-soldered cabling. Folks who can do their own rigging like you don't benefit nearly as much from what I do, and I'm certainly not going to be upset about self-sufficiency.

Glad I caught your edit before replying. My only affiliation with bitcoinware.net is they bought my stuff to resale in Canada, same as my affiliation with HolyBitcoin and ASICPuppy in the US. If it has my name on it, I manufactured it in and shipped it from Missouri, USA regardless who is the reseller. The only place I have ever listed Compacs for sale is on this forum, so if you see them for sale anywhere else it's a reseller (authorized or otherwise) and I claim no responsibility for their actions. The only website I'm "behind" is my own sadly neglected one, gekkoscience.com

Yes, here's a link showing them connected to a Dell PSU:
http://www.aliexpress.com/item/10PCS-NEW-6pin-6p-Female-PCI-E-Graphic-Card-Power-conversion-Cable-for-DELL-2950-1470/32516294320.html
I got the ones without the vinyl hoods from a local hardware store.  I got the cables (16AWG/18") from Maxime at Cryptominer for about C$3 shipped.  It's worked great for months.

I'm making my own active-high external power-on for ~10c each.  A single 817 opto with dupont cables connected to the power LED on the mobo, and the output to PS_ON and Gnd on the server PSU (PS_ON to VG works as well on the Dell since it is an open collector output).

I just did more searching on you, and see that you're behind bitcoinware.net.  Knowing that, it's highly unlikely I'd do business with you.
https://coinforum.ca/discussion/3256/free-snow-from-bitcoinware

Edit: or maybe you are just a supplier to Bitcoinware.  It adds to the confusion given your .sig says "made in USA", but I think I saw one of your posts saying you ship your cables from Toronto.
http://www.kijiji.ca/v-other-computer-products/city-of-toronto/gekkoscience-usb-compac-btc-miner-8-16-gh-s-0-3w-gh-bitcoin/1128683339

Are you asking about 1/4" quick-connects to tie directly onto the power blades from the PSU? You could have asked, because I've made cables like that. I don't think it's a great long-term solution but it works. I have some temp supplies in hosting set up just like that.
Also all my breakout boards have an active-high external turnon pin specifically so it can be used alongside an ATX PSU without additional hassle. My first server PSU mods were for a GPU rig, so that feature's been there since the beginning.

Your breakout boards look nice, but for PSUs like the Dell 750p and the IBM/Delta DPS1520AB 6mm spade connectors are simple and cheap way to go.  If you sold 18" 16AWG cables with the 6mm female spade connectors, I probably would've bought some from you in order to avoid the crimping.
For my rigs I use a standard PC PSU for the mobo, and server PSUs for the GPU PCI-e power connectors.  I'm planning to link the power control so the server PSU shuts off when the mobo powers off once my order of optocouplers comes in.

I would definitely be interested in enough for 12 cards!

i would definitely go for dps-2500 then. buying from afar, one should put a room for upgrade and backup/extra psu's.

the dps-2500 is the same wire pin out but is more powerful .

The dps-2000 should do six r9 390s,but you do have tropical heat issues.  The dps-2500 certainly can do six units even with your temps at 40c

that would make it even better

well it is not purely 2k psu in terms of 12v, looking at seasonic psu's they rate their psu in watts in terms of 12v, by using a stepdown for 12v it is technically a little bit lower for 2k for "pure" 12v utilization due to some of it will be used by 5v plus conversion losses , besides my country is in a tropical area so maximizing power capacity = heating up the psu more and heat can greatly shorten the life of the psu.

and the socket 775 boards i mentioned just have 4x pcie slots = 4 gpus..if ever i use a motherboard with more pcie slots i will analyze heat and power draw to maximize utilization... until then the convenient and safe side is 4 gpus

i think i can do with the stepdown for the molex powered risers..but not with the pico atx

the only thing that will be powered by the low-cost, low-power, good quality surplus psu are the cheap 775 socket motherboards, quadcore cpus, ddr2 rams and 80gb hdds..the expensive GPUs cannot be harmed with this setup since it will be connected only to dps2000 via powered risers and 6+2 pcie pins..

actually it can handle even more, atm my 4x390x mining etc/sia pulling 1350W from the wall

thanks for the offer and the information, i will keep it in mind..it might become handy in time.

but, someone i know in the US is a family member who from time to time sends stuff here, he might even pay the shipping for me, mix it with other stuff in a huge box. I'm in asia BTW.

@ arielbit 

I have helped European buyers of sidehack's gear.
I helped 2 people out see thread below

https://bitcointalksearch.org/topic/hacked-s7ln-group-buy-1509068

if you look here I helped euro buyers of the avaon 6's

https://bitcointalksearch.org/topic/new-avalon6-group-buy-interest-thread-650-usd-closed-1391814


So if you cut a deal with sidehack I would be willing to help with logistics.

My fees were $0

But of course the extra shipping would be on you.

I always used the cheapest safe shipping and always was transparent.  To Europe shipping was best via usps.com

To Canada ups.com was best

Yeah, you'd still need 3.3v as well for the 24-pin ATX connector... Really with things like the RX480 reference boards drawing more than typical current, I just like to over-engineer on the enclosure/power side of things.  DPS2000BB's are cheap relative to anything else - and if I can get some really nice boards/wiring from Sidehack to compliment them, I think it's money well spent.

I definitely agree with you about availability - and that's why I love getting things from Sidehack, he turns them around quickly and the quality is great.  It's a bit trickier obviously when you're non-US, as you need to plan in advance a bit more, but at least for me it's pretty rare that building new machines comes as a surprise - generally I buy in batches.

As far as troubleshooting power, I've basically been running first the IBM 2880W PSU's, which I had no problems with except with the breakouts.  I switched over exclusively to the DSP2000BB's last year, and they've run flawlessly - but to be honest, the main reason I used it with the GPU builds was because I have about 100 of them not being used right now, and 2000W was just about perfect power-wise.  Since all the breakouts and cables are of a known high quality, it just eliminates the #1 issue I've had in the past.  And as I mentioned above, I'll probably be double these up to 4k when Optimizer finishes those boards in a few weeks - but not for any reason other than because I have room in the case, it will run much cooler, and give me a bunch of extra PCI connectors.