leowonderful
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February 03, 2017, 09:49:37 PM |
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Thanks guys I'm understanding all this now. I've been playing around with the clock settings and voltage, and after dialing the voltage to .77V (I don't have a voltmeter on me so that's based off the picture at the beginning of this thread) I was able to hold 300 MHz for ten minutes before the stick seemingly crashed and couldn't be recognized as a device by both cgminer and Windows. After unplugging it for a little bit I got it working again and it's been humming along at 290MHz with no issues for well over an hour now.
I've seen plenty of posts where people get their compacs to run at 20GH/s (I'm sitting at 15GH/s) so I'm wondering what I'd need to do to get it there without crashing. Do I need to dial up the voltage more? Or is the current draw insufficient (I have it in a 3.0 USB port on the front of my desktop)?
Yeah, you can't get above 295mhz or something like that without a powered usb hub because USB 3.0 only supplies so much power. Superbpag usb hubs are nice and cheap and do the job well. Once you get a powered hub 400mhz is reachable with a fan; past that, it's almost impossible to go higher to my knowledge.
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Biodom
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February 03, 2017, 10:26:22 PM |
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Thanks guys I'm understanding all this now. I've been playing around with the clock settings and voltage, and after dialing the voltage to .77V (I don't have a voltmeter on me so that's based off the picture at the beginning of this thread) I was able to hold 300 MHz for ten minutes before the stick seemingly crashed and couldn't be recognized as a device by both cgminer and Windows. After unplugging it for a little bit I got it working again and it's been humming along at 290MHz with no issues for well over an hour now.
I've seen plenty of posts where people get their compacs to run at 20GH/s (I'm sitting at 15GH/s) so I'm wondering what I'd need to do to get it there without crashing. Do I need to dial up the voltage more? Or is the current draw insufficient (I have it in a 3.0 USB port on the front of my desktop)?
few things: 1. Y-USB connector (or a bracket that phil shows in his pics), so you bring power from two or more USB slots to one stick. 2. Intense cooling (I had a Vornado fan at full blast at a 5-10 inch distance). A very large custom heatsink would probably do it as well. 3. Slowly dialing up frequency at 800 mv (i got it up to 435 Mhz for 24 Gh) check this out: https://i.imgur.com/WVfQw3j.pngTrying this can fry your stick; I am not responsible, proceed with caution.
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philipma1957
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February 03, 2017, 10:41:19 PM Last edit: February 04, 2017, 02:03:16 AM by philipma1957 |
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Thanks guys I'm understanding all this now. I've been playing around with the clock settings and voltage, and after dialing the voltage to .77V (I don't have a voltmeter on me so that's based off the picture at the beginning of this thread) I was able to hold 300 MHz for ten minutes before the stick seemingly crashed and couldn't be recognized as a device by both cgminer and Windows. After unplugging it for a little bit I got it working again and it's been humming along at 290MHz with no issues for well over an hour now.
I've seen plenty of posts where people get their compacs to run at 20GH/s (I'm sitting at 15GH/s) so I'm wondering what I'd need to do to get it there without crashing. Do I need to dial up the voltage more? Or is the current draw insufficient (I have it in a 3.0 USB port on the front of my desktop)?
few things: 1. Y-USB connector (or a bracket that phil shows in his pics), so you bring power from two or more USB slots to one stick. 2. Intense cooling (I had a Vornado fan at full blast at a 5-10 inch distance). A very large custom heatsink would probably do it as well. 3. Slowly dialing up frequency at 800 mv (i got it up to 435 Mhz for 24 Gh) check this out: https://i.imgur.com/WVfQw3j.pngTrying this can fry your stick; I am not responsible, proceed with caution. yeah I did 2 bridges and then a y-cable getting me in the 440 range a year ago. I was lazy I did not want to swap heat sink. this black hub on eBay is a beast I have the older silver version mine gives 0.9-1.1 amps and 2.2 amps with the bridges I have mine is usb 2.0 the black one is usb 3.0 http://www.ebay.com/itm/Eyeboot-19-Port-40A-USB-3-0-Hub-110-240V-2-amps-per-port-/351720554389?
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sidehack
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February 04, 2017, 01:53:30 AM |
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For extreme overclocking I definitely recommend VH's new cgminer driver over Novak's. The original ramp code, while still better than nothing, was still pretty hard on the works as far as step current is concerned (which can cause the USB voltage to bottom out or trip the voltage controller and break hashing). VH's new driver exactly emulates the S5's smooth linear power increase and should make hitting the high frequencies quite a bit easier.
The new 2Pac also has hardware improvements to isolate the buck controller from voltage ripple resulting from high power use by the ASICs, so with both that and the better driver overclocking on those is a breeze. I hacked a basic version of this into "Max", the uber-test-Compac we pushed almost to 500MHz back in the day.
As Biodom mentioned, a larger heatsink will also do a better job of cooling when you get into high power ranges. Somewhere in here I posted a mechanical diagram of the heatsink which gives screw positions if an overclocker wants to make his own heatsink. There are also several examples of over-spec heatsinks posted throughout.
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philipma1957
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February 04, 2017, 02:04:26 AM |
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For extreme overclocking I definitely recommend VH's new cgminer driver over Novak's. The original ramp code, while still better than nothing, was still pretty hard on the works as far as step current is concerned (which can cause the USB voltage to bottom out or trip the voltage controller and break hashing). VH's new driver exactly emulates the S5's smooth linear power increase and should make hitting the high frequencies quite a bit easier.
The new 2Pac also has hardware improvements to isolate the buck controller from voltage ripple resulting from high power use by the ASICs, so with both that and the better driver overclocking on those is a breeze. I hacked a basic version of this into "Max", the uber-test-Compac we pushed almost to 500MHz back in the day.
As Biodom mentioned, a larger heatsink will also do a better job of cooling when you get into high power ranges. Somewhere in here I posted a mechanical diagram of the heatsink which gives screw positions if an overclocker wants to make his own heatsink. There are also several examples of over-spec heatsinks posted throughout.
Sidehack if I ship a bridge could you make one that handles 4 amps? I would use it with the new black eyeboot usb hub. No rush but I am thinking down the road if you make bf sticks.
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sidehack
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February 04, 2017, 04:04:45 AM |
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Maybe. Does it have any active parts or does it just link two jack "rails" and only send data down one? Also is the spacing the same between the hub it was built for and the one you want to use a 4A bridge with?
I should probably one of these days get back around to my high-power-handling hub project. Maybe if 2Pac assembly goes smoother than expected, but that's going to depend a lot on whether or not the guy helping starts being more effective.
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hurricandave
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February 04, 2017, 04:38:25 AM |
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Would it be safe to say solder a 4-pin molex to the usb board/pads on the compact and plug that directly into an ATX2 PSU with only the 5v+ and -ground pins populated as long as the USB connector had the + and - cut? Or would it need the - ground on the USB cable left intact?
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zOU
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February 04, 2017, 06:55:05 AM |
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As Biodom mentioned, a larger heatsink will also do a better job of cooling when you get into high power ranges. Somewhere in here I posted a mechanical diagram of the heatsink which gives screw positions if an overclocker wants to make his own heatsink. There are also several examples of over-spec heatsinks posted throughout.
you mean this ? ![](https://ip.bitcointalk.org/?u=http%3A%2F%2Fgekkoscience.com%2Fimg_stash%2Fcompac_heatsink.GIF&t=665&c=BJ9bAkl5i0cv8w) Note that the Compac heatsink actually has 8 fins. I wasn't really specifying the profile so much as the dimensions.
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vapourminer
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what is this "brake pedal" you speak of?
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February 04, 2017, 12:55:57 PM |
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Would it be safe to say solder a 4-pin molex to the usb board/pads on the compact and plug that directly into an ATX2 PSU with only the 5v+ and -ground pins populated as long as the USB connector had the + and - cut? Or would it need the - ground on the USB cable left intact?
you just isolate the 5v. ground stays connected.
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philipma1957
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February 04, 2017, 07:00:51 PM |
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does the silver and black hub have identical spacing if they do I can use the bridge to go beyond 2 amps. looking down the road for max power available.
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gorillazilla9
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February 04, 2017, 08:18:53 PM |
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What would be the max frequency and voltage I could set on the compact with just a single USB 3.0 port? I'm just a broke college student so I can't really afford to invest in a $200 powered USB hub, and I know I could achieve a similar effect with a Y-cable in terms of current, but it'll be a while before I could get one.
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leowonderful
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February 04, 2017, 09:16:02 PM |
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What would be the max frequency and voltage I could set on the compact with just a single USB 3.0 port? I'm just a broke college student so I can't really afford to invest in a $200 powered USB hub, and I know I could achieve a similar effect with a Y-cable in terms of current, but it'll be a while before I could get one.
You could try using the sixty watt Superbpag ones that only cost 36 bucks with prime on amazon- they're nice and reliable and you won't have to worry about power draw unless you have more than five compacs. I think you can get around 400mhz with aquedate cooling with a Y cord; I run my gekko at 350 on a Y cable.
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sidehack
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February 04, 2017, 09:17:21 PM |
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If you got a decent soldering iron, buy an $8 hub off eBay and beef up the rails. That's how I get powered hubs.
Or do that thing he just said.
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leowonderful
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February 04, 2017, 10:25:51 PM |
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If you got a decent soldering iron, buy an $8 hub off eBay and beef up the rails. That's how I get powered hubs.
Or do that thing he just said.
I've always wondered how people do that... I have a cheap soldering iron but I don't want to break anything. Do you have any instructions on how to do this? I have plenty of hubs and one more powered hub couldn't hurt.
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zOU
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February 06, 2017, 06:16:10 AM |
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If you got a decent soldering iron, buy an $8 hub off eBay and beef up the rails. That's how I get powered hubs.
Or do that thing he just said.
I've always wondered how people do that... I have a cheap soldering iron but I don't want to break anything. Do you have any instructions on how to do this? I have plenty of hubs and one more powered hub couldn't hurt. I googled:"more power usb hub soldering" and that came up as the 4th link... https://bitcointalk.org/index.php?topic=1152953.0
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ParaplegicRacehorse
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February 12, 2017, 03:34:56 PM |
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Two days ago, I received my Compac (serial #GS-10003894) from seller GekkoScience on Amazon (shipper: Ultimate electronics outlet). I was a little surprised at how small it really is. I was very disappointed it came with no documentation, just the device nicely wrapped in bubble-stuff. Fortunately, I already knew about this thread and I spent much of the last two days reading it.
Of course, I couldn't resist also playing with while reading. I compiled bfgminer straight from git (5.4.2) and toodled right along. bfgminer because I wanted to watch what happened when I messed with freq without have to start and restart over and over again.
This poor little guy got too hot to hold my fingers on, even at 100MHz! I suspect it's a power supply thing. My poor little Dell Mini also got really hot right near the port it plugged into. I have a hub coming and I'll find out then. No voltage measurements, yet. Fiddling with the pot didn't seem to make any difference in HW error rate - over 2000 in 2hrs of run time at 150MHz.
I'm compiling vh-cgminer as I type. Maybe (unlikely) the heat has something to do with software. It won't hurt to let the power ramp up instead of spike, either.
I really wish I had known about the 2Pac when I ordered. For what I paid for this original, I could have ordered a pair of 2Pacs. (@sidehack, look for an email from me inquiring about them).
Edit: vh-cgminer doesn't do the TUI like ckolivas? Compiling stock cgminer to compare.
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sidehack
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February 12, 2017, 03:44:16 PM |
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Heat means power. Power means voltage times current; voltage is the pot adjustment, current is proportional to operating frequency. If it's too hot to touch at 100MHz the voltage is set way too high, because at optimum settings 100MHz should be about 2 watts.
I can't speak for used hardware, but when sticks ship from me they're tested to stable operation at 150MHz, usually voltage set between 640 and 660 millivolts. Over 660 and the ASIC gets replaced because it's running too hot. Nothing ships if it can't hash at <30 errors per hour and <660mV. If your stick can't do that there's probably something wrong with it.
Also, there is no "seller GekkoScience" on Amazon. GekkoScience (me) is the manufacturer but has never directly sold them on Amazon. Far as I know, about the only Amazon seller I've directly supplied was BitMiner Joe, aka CrazyGuy here on the forums.
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ParaplegicRacehorse
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February 12, 2017, 04:35:02 PM Last edit: February 12, 2017, 04:53:08 PM by ParaplegicRacehorse |
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Heat means power. Power means voltage times current; voltage is the pot adjustment, current is proportional to operating frequency. If it's too hot to touch at 100MHz the voltage is set way too high, because at optimum settings 100MHz should be about 2 watts.
Adjusting the pot doesn't seem to have any heat affects. I'll get some measurements soon and reset accordingly. At freq 150-200, vcore should be in the neighborhood of 0.6, correct? Edit: Now I feel silly. You had the voltages right in your reply. Disregard the above. Edit 2: I don't recall the specs on this Delll Mini. It's likely I have plugged the compac into a USB1 port, which doesn't supply much in the way of power. I'll have to doublecheck calcs, but if this is USB1 that could be the whole heat/voltage thing right there. [/edits] Is it safe to ground the reset patch while the device is actively working and do I need to use the ground patch or can I use an external reference ground? Also, there is no "seller GekkoScience" on Amazon. GekkoScience (me) is the manufacturer but has never directly sold them on Amazon. Far as I know, about the only Amazon seller I've directly supplied was BitMiner Joe, aka CrazyGuy here on the forums.
Okay. Taking a closer look at the Amazon listing, it's not the seller's name but a brand name listing with multiple sellers of used gear. Unless these are becoming collector's devices, I'm seriously thinking about refrigerant-cooling. A water-cooling plate could fairly easily be converted for use as a cold-plate in a gas absorption type system. Ammonia is easy to come by. Not sure what I'd use as the external heat source, though. I may simply use the chip to boil the ammonia (and carry away the heat) with a fan-cooled radiator to "re-compress" (liquefy) the ammonia. Suitably sized compressors are likely to be impossible to find for "modern" refrigeration method.
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