Topic: [RUN 2 CLOSED][SIDEHACK STICK]GekkoScience Compac Official sales thread - page 22. (Read 69935 times)

hack what time are you guys going to be at the shop if your not there already moms going to head home here in a bit

As labeled in Phil's picture:
1 = GND = BLACK = Ground (0V potential)
2 = D+  = GREEN = differential data pair positive
3 = D-  = WHITE = differential data pair negative
4 = VCC = RED   = USB bus voltage (+5V potential)

If you're trying to measure off of those pins, be careful not to short pin 4 with the shield around the USB connector, as that's shortin VCC and GND.  One of those little USB meters is much more convenient.

Gotcha, thanks. Could you tell me the pinout for the 4 pins? I have been assuming i would use those pins;

(Shamelessly ripped off Phil's picture)
As Labeled?

All Phil's meter (which Novak and I also have one each for testing sticks) does is measure the DC voltage same as if you put a voltmeter across the pins on the jack. 5% drop on the bus line gets you 4.75V from 5V in, which you probably don't want to go below that. Your voltage will drop because of the resistance of the traces between the 5V source and the actual jack, and depending on how much current you're pulling it could eat up a fair bit of power.

My test setup uses a cheap unpowered hub off a laptop and a long USB extension cable. The no-load volts is 5.00 but with a 610mV/150MHz stick I see 4.35V at 610mA, so my stick is using 2.65W and my transmission losses are 0.4W or about 13% of the total power. That's pretty bad. The powered hub we use to burn in has reworked traces off a Molex, and probably doesn't drop 300mV at the port for a 2A load. Novak's taken sticks up close to 3A on it without trouble.

Is there anything preventing me from using a multimeter and check the dc volt on the sidehack stick for the same result? I assumed i would be able to check using the metal pin that connect the usb port to the PCB?

Other than that, i forgot the word that was used when i was explained how to check for the limit of your hub/usb port but it is the same process. When volt start dropping, it's because some current is being eaten by the hub. Hence you found the limit.

so my hub is using 4 ports and about 3.55 amps to run 2 sticks at freq 300.

the power brick reads 5 volts and 4 amps     so at 3.55 amps out of 4 amps that is it for this hub 2 sticks at freq 300

I derate my brick's amps of 4  like this .8 x 4 = 3.2 amps so I am just beyond the hubs specs.

So my point is I need the meter to have a chance of knowing what my hub can do.

that voltage drop from 5.18 to 4.46 is a good clue I am maxxed.

as for what does a stick do on a good usb hub .  by good one that will do .5 amps and keep volts up at 4.8 or so  the stick will do 125mhz to 150mhz

but with out the meter you can not tell if your hub is good.

here is the meter it is showing 5.18 volts and 0 amps empty and it is showing 4.46volts at 1.75 amps on a freq 300 stick.  so even with a y cable with extra power available volts drops from 5.1 to 4.4  but still stable stick.

see 5.18 volts and 0 amps




drops to 4.46 volts and 1.78 amps

guys there is a simple meter to show the power draw.  cheap amazon sells it

I have two wait for a link


http://www.amazon.com/gp/product/B00J3JSEG6?


now here are 2 sticks over clocked and running hard at freq 300  wait for photo.

see below with no meter hooked in.



The y-cable for plenty of power in the setup below.  easy freq 300


these need a fan or they get too warm and crash




the y-cables allow me to clock safely to freq 300 not bad

If what you're asking is; "How do i figure out what is the max watt that X usb port can safely support?" then the answer is "Its either written under the usb hub or you need to test it out yourself which is pretty complicated imo." The reason is because simply the components in the USB hubs are lesser, smaller, not built to support higher current.

As i can't find the value on my usb hub or in the documentation i will have to poke around with my multi meter, slowly raising the values until i get less than i'm supposed. At which point i can guess that the current is not being transmitted properly because some components are overheating, generating heat = some current is wasted. Then tone it down to the point where i'm no longer wasting energy/overloading the port.

600mV, 137.5MHz for 7.6GH should come in under 500mA draw. You might be able to push it closer to 150MHz on a slightly lower voltage and keep under 2.5W


One problem keeping your question coming through is the inherent fallacy of statements like:


One thing I've run into a lot, which baffles me to no end, is how many people don't understand current. I saw it a lot with people asking about PSUs. Electricity parallels plumbing in a lot of ways; if you think of electron flow as a fluid flow it's pretty straightforward. The water pressure at your bathroom faucet is the same as the tub spigot (it has to be, since they're all tied into the same mains supply), but the faucet can be adjusted to supply between 0 and about 2 gallons per minute, where the tub spigot can be adjusted to supply between 0 and about 10 gallons per minute. That's the current - the flow rate. Electrical current is literally a measurement of how many electrons are moving per second.

Not all USB hubs are created equal. Some of them have really small weak power traces, and some have big beefy power traces. Your bathroom sink has small pipes which constrict the flow so the best you can do is 2GPM. The pipe running to the tub spigot is bigger, so less constriction and a max flow of 10GPM. The electrical "constriction" on small traces in cheap hubs keeps you from being able to run higher currents through them. Higher-quality hubs with beefy power traces will handle more current.

Just like your faucet can be turned anywhere between zero and full flow, a USB port isn't always pushing exactly 500mA. It depends on the load. At 150MHz the Compac will be asking for about 550mA off the line. At 250MHz it'll be asking for 1000mA. In this example, the Compac itself is functioning as the valve on the faucet. The pressure behind the valve doesn't change, but by adjusting the valve you adjust the flow rate. The actual power being delivered is volts times current, or pressure times flow rate if you will.

I will do that because I don't think my question is coming through here, the answers/examples ya'll are giving me are nothing I don't already know so the failing must be in my asking.

Back to the topic at hand, maybe my last question above can be answered: What is the max. frequency that the compac will run on @ 2.5 watts?  I.e. Assuming a maxed out "standard" usb 2.0 port 5V @ 0.5A, what is the max. frequency the compac will run?

Interstate speed limit's 70, so vehicles should be able to do 70 to drive there. My '85 Ford will do 70, but so will a Corvette. One just does it better, and can do a lot more.

The standard isn't "exactly 500mA", the standard is "at least 500mA". Some hubs are built cheap and can do 500mA safely but have such weak lines that they lose power when you push it past that and it stops working right. And some are freakin' stout to push 2A or more without trouble.

Take a look at AJRGale's hub modification thread over in the Hardware forum. That's a lot better place for this discussion.

Because Volt is not how much power it use, its like the bandwidth or like how large the highway is. Its the electrical potential. I guess.

The amp is the flow rate. So when you do amp * volt, you get how much watt it can support. Watt = Joule/s.

But if the wires are super super tiny, you maybe only be able to support 0.1amp. Which would be 0.5Watt since 0.1a*5v = 0.5Watt.

Nothing prevent you from taking 10Amp of power, which will drain 50Watt but since the physical wires and stuff are not able to support that much current, it will fry.

So if USB standard is standard, then all 2.0 ports are created equal and I fail to see how one product/hub can supply "more power" than another.  Shouldn't any usb hub should be just as good as the next one since they all supply the same power per port?  Whether you have a 4 port hub or a 40 port hub, the power per port is the same.  I'm missing something here, someone please hit me over the head with it.

I'm also curious how one gets 1.5 amps or more out of a single usb port, was the port modified to supply additional amperage?

What is the max. frequency/voltage that the compac will run on @ 2.5 watts?

Electricity is so confusing.
 

Because USB standard is, and always has been, 5V at the port. If you plug any USB device into 12V it will likely burst into flames. Your hub takes in 12V and steps it down to 5V internally because high-current 12V bricks are easier to find, and power transfers with less loss when the voltage is increased and curent is decreased.

My hub takes power right from 12v, why would I only see 5v at each port?

Electrical stuff always baffles me.  Only had to take 1 EE class back in college, thank god.

If you're asking USB power, you're looking at 0.5A off 5V so 2.5W

So they replied back to me and said "Maximum is 500ma" which I already knew is the max rating for USB 2.0, but I don't think it answers our question.

0.5 amps off my 12v computer psu = 6 watts per port, right?  Am I missing something?

I believe the strongest argument is their ability to create something, from nothing (excuse my French) and sell it for a set price with very little markup.  And still be here daily to answer and bullshit with us.  Something that's lacking in the community.  When do you see Bitmain communicating, maybe a post once a week or at release.  I say job well done and look forward to my order and the next one.

I hear ya, but I couldn't believe the price was $25 each.... I thought it would of been more, hats off to you. I love to tinker (got that from my dad R.I.P.) so I'm sure you enjoy yourself in the end of it all. Designing and making a miner and putting it out into the world......hell Id put on a smile with assembly and tinkering. Its like building a project car, in the end you stand back and look around with a big smile on your face, and that first successful test drive *speechless*