 Show Posts
|
|
Pages: [1]
|
Okay, but don't forget that the limiter is heat in the main regulator. Depending on heat, it could cut off at 15A or so, which is only about 6W per chip.
Also, that's a lot of finagling. I'd say once you're taking stuff apart it becomes "roast at your own risk".
I fixed that problem, added a heat sink to the bottom of the board and simply air cool my pods with a common fan. So far it's working quite nicely. What I did was lay a bead of high temp epoxy around the area, leveled it, let it set. Then I filled the center with heat transfer compound, lay another bead of high temp epoxy and attached a heat sink. Not perfect, I would have preferred a compression seating, but it doesn't let go. Cheers |
|
|
|
I'd be interested in the box design. Would we need two fans to pull and push air out of the box?
PM me and I will send you a jpg, hand drawn of course for now, but you'll get the general idea. I use 2.5lb soundproof foam for my noise suppression systems. Makes the box a bit bigger but if you have a dual fan arrangement on a single rad like I do, you are working with 18" wide by 12" high and about 20" deep. The ducting is set up almost like a subwoofer using a right angle baffle as the air intake. This way you can pad the air intake and exhaust with sound insulation and mount the pump inside on either springs or rubber bushings. Rad and fan also mount inside about 6" from the right angle exhaust duct. I keep reservoir outside. Cheers |
|
|
|
Hey all, We are making Liquid Cooled Heat Sinks available for the GekkoScience Terminus R808. Presently, we am using a 1" PVC or Acrylic Body (new version will be 1/2 thick body) on 1/4" thick Aluminum contact plate, but these contact plates can be copper if you prefer for a little more, like around $5 more. All mounting holes drilled and tapped. You can buy them off the website at http://www.dal-tek.com or ebay shortly.   Cheers |
|
|
|
The heat and noise are both a factor of power density, which also has an adverse effect on longevity. Home mining's biggest issue is manufacturers who think it's appropriate to stuff multiple kilowatts into a cracker box. I am testing for noise levels today. One simple fix for pumps is to put them into a soundproof box with a pair of passive air circulation baffles, the foam is only around a $1 a square foot and the box is easy to make. I used the wall foam, 2.5" egg carton style, in my recording studio and at 2,400wrms, you couldn't hear anything in the control room, except through the control room monitor speakers. If anyone needs the design, just ask and I will draw it up and provide a public link. There are ways to get around everything ;-) I think I am going to put these oil/water cooled heat sinks up on ebay, might as well let everyone get some since I did all the modelling and production of my own units. Cheers |
|
|
|
Had a buddy with a micro-cray about 15 years ago. It was a little bit bigger than a standard desktop, it was filled with oil. Of course it was built that way, so all of the electrical connections were apparently sealed or soldered, it had it's own recirculating system. I never did take it apart though, too messy lol. You could possibly do the same thing with the r808's, but you will have to make sure that any connections are sealed or soldered. Just a secondary note, you'll still need a pump, radiator and fans since if you leave the oil in one place without cooling it will eventually exceed the temperature working limits of the chips. Cheers |
|
|
|
If you've got more questions, I'd try searching first. This thread and the dev thread can tell you pretty much everything, including the answers to all of today's questions so far. I have been searching the forum for a dev thread for the terminus R808, unfortunately haven't found one specifically. I can figure it all out, I have a lot of toys ;-) Anyway, I figured I would use medium velocity liquid transfer (less than 0.25 seconds/cm) across the highest surface area I could get, I wanted very little pooling time. So far so good. Figured I'd throw them up on one of my sites that I just set up last night for other projects I am doing (you can see site's not complete, have a lot of text to add lol). Two different flavours, Acrylic and PVC, I think I'll cut the thickness in half. Might change to 1/4" copper plate rather than aluminum as well for oil usage, water creates too much oxidization with copper. I think this should work pretty well with a 300mm reservoir, 100 gph high flow/low pressure pump and a 14" x 7" radiator with dual 6" fans. It would be nice to have the regulator board cooled as well, but I'll look at that tomorrow. Cheers |
|
|
|
I'm gonna bet most everything you need to know is in the first post. I went through the first post when I got the r808's. I see the core voltage is controlled by the pot, that's fine. What do the jumpers do? I see no reference for them? Command line control was easy for changing freq speeds and step up times, I just wrote a config file. Like I said initially, nice little unit, easy to manage, I just want to push the envelope a bit, get 275mhz down to an operating temp of around 35/40 degrees C and then run up from there. I can monitor actual core temp via the USB I believe. I would have to look up the command. Is there any way to increase clock frequency above 275mhz other than command line or possibly changing hardware? Is there a firmware "governor" on the unit, so the frequency cannot be increased past 275mhz? Cheers |
|
|
|
Okay, but don't forget that the limiter is heat in the main regulator. Depending on heat, it could cut off at 15A or so, which is only about 6W per chip.
Also, that's a lot of finagling. I'd say once you're taking stuff apart it becomes "roast at your own risk". I hear you ;-) I was thinking of adding a side-sink just to cool the regulator area. It will be an afterthought though as I am dealing with the main 8 chips first, I can add-in on the side for the regulator. It would be nice if I could oil cool that section as well, but lot of hills and valleys to deal with. I have the cnc and a laser scanner I can use for 3D profiling, so maybe. The main parts are almost milled, one is done, but I just used a ball mill for now, doesn't have to be perfect and pretty for prototyping, just functional. I didn't get a lot of setup instruction with these. I can use command line management to control many functions on the R808, but I didn't get anything on jumper settings or the pot function? Would you have that handy? Cheers |
|
|
|
|
Ok, I designed an oil/glycol/distilled water cooling system (I prefer oil as it's electrically non-conductive), dual 1/4" NPT inputs with a single 1/4" NPT output. I only had 1/4" aluminum hanging around for the contact plate, but I have 1" PVC and Acrylic that I could throw into the CNC quickly. Looks like by tonight I will have a working solution to seriously cool these units. I have a flow switch around here somewhere to shut down the units if the pump stops, and I have a spare radiator, fans, reservoir, pump, fittings, etc.
Will post pictures later today when I get the units ready. One question, how does this effect warranty, using a oil cooled system with a no-flow automatic shutdown cutoff switch?
Cheers
|
|
|
|
You were lied to, or you seriously misunderstood. Who did you buy from?
These are tested at 200MHz, with a practical max of 275MHz. With 55 cores per ASIC and 8 ASICs per board, that's GH=0.44*MHz for 275MHz clocking in at a theoretical peak of 121GH.
Under pretty ideal cooling and power conditions, the BM1384 ASIC is good to around 500MHz which means the absolute best case liquid-cooled-miracle performance for this device could only be 220GH, still less than half what you want.
(in case you're wondering, I designed and built the R808 so I know more than "them") Well, then you'd know ;-) I am working on something, will get back to you shortly. As an aside, at 200mhz, I generally run around 80-100 gh/s per unit on CKPool, which seems pretty fair. Only problem I have ever really had with the unit, apart from not being able to cycle it up to higher rates, over heat constraints, is the regulator heating (which is why I use an additional fan). Cheers |
|
|
|
I'm assuming 480GH is the desired aggregated speed from at least 4 units? That's about 275MHz, which is pushing pretty hard. Some people reported taller feet and under-board airflow helped increase stability. The actual limit on this board is thermal derating of the main regulator, which is the rectangular add-on board in the corner by the pot. Keeping that cool will also help.
Yes the fans on these are pretty crappy and I won't be using them again. They say max rate is 480 gh/s per each unit. I have multiple units, it would be nice to operate at around one terrahash per pair. I noticed as well a lot of heating in the power regulation modules. I guess I am going to have to make a plan as I don't really like the thermal cooling system. Cheers |
|
|
|
|
I bought a few these units, have to say they work pretty nice. My only problem is getting to the max hashrate speed. You know the heating problems. Any solutions out there? I have noticed fan slowdown approaching fan failure on these units, a couple of times 1 of the fans refused to start, but it is a fan bearing issue. I don't want to zombie these units, so I keep extra fans on them at all times and I don't run them higher than 200mhz.
Just looking for a good thermal solution to run them at the full 480 gh/s.
Cheers
|
|
|
|
|
