How to make a E-Power from a EVGA Classified Card.
I wanted a E-Power card but of course theres none availble, so I looked into trying to build my own. After some preliminary research and talking to electronic engineers I determined building one from scratch is essentially impossible if not very expensive. I am not an electronics engineer or have any professional training other than basic understanding of electronics.
Initially I discovered a thread in the kingpin cooling forums(1)
. The concept of converting a dead graphics card into a "zombie" like an E-Power or equivalent card is proven here.
The next task was to examine the possibility with newer cards (older than 5XX series cards). Alas, I arrived at a pitfall with no one doing this with a recent card. Fortunately again kingpin cooling forums came through(2)
I discovered key voltages and signals needed to power a card without the GPU attached or PCI-E Power. To save you the necessary reading of the hundreds of posts, I will summarize the voltages needed to power the GPU VRM/PWM. Basically you only need 3.3V, 12V, and 5V rails(an exception can be made for this rail as some don't use 5V). The 12V and 3.3V is usually only generated by the PCI-E slot
(3) and the 5V rail is generated my a LDO somewhere on the card.
Why do we need those 3 voltage rails? The reason is found within datasheets of VRM, specifically I will be using the Chil CHL8318 as an example(4)
. VCC for this VRM that controls the VCore is 3.3V. The 12V is utilized in the PWMs to convert the voltage into usable 1V-2V depending of current capability(power limit) of PWM. 5V is sometimes used for memory VRM/PWM and GPU PWMs, though I haven't been able to specifically locate it. These voltages essentially are what tell the card to power on and run, if we can find a way to supply these rails we can power the VRM/PWM independently without the PCI-E and GPU Core attached.
Before we can find a way to generate these voltages we must locate them via 2 methods, both require a DMM with a resistance and voltage measuring capability. The first is by running the card and finding the 3.3V, 12V, and 5V inputs to the VRM
. I stress the VRM as thats the most important factor here. The second is more complicated and most important, we need to trace the 3.3V and 12V inputs from the PCI-E power pins. Find them by using the picture down below to trace them to the side where the VRM is:
12V hookup is pretty simple, run a 12G or similar size wire from the +12V 6/8 PCI Power connector to where the PCI-E power connects to. 5V is tricky and varies from card to card but, in the case of EVGA Classified cards its typically an LDO(one of these
). The best way to locate it is by finding using the DMM while its running and locate the 12V input. In my case(680 Classified) the 5V circuit was where the 12V from the PCI-E went to.
As for the 3.3V, be prepared to find or buy some ICs. 3.3V rail has to be generated by a circuit 99% of the time as the PCI-E slot provides the voltage. We are going to use a simple circuit made by TiN(5)
specifically made for this purpose. We need a LM317 or equivalent LDO that can provide up to [email protected]
, 2x 10uF MLCC capacitors, 220 ohm , 330 ohm, and 390 ohm(390 is only needed if your'e using an LED) MLCC resistors, 100uF 20V tantalum capacitor, 47uF 20V tantalum capacitor, and a SMD size LED is optional. I didn't use an LED. Please read the guide on how to make the circuit as it is way to long to add here.
Once we have the 3.3V circuit made we hook it up to our 3.3V rail and were almost good to go.
To control the voltage we do a simple 500 Ohm Variable Resistor(VR) to ground mod, on the CHL8318 its on pins 4/5:
Unfortunately the site where the picture being done on a E-Power(Same setup as a 680 Classy) is down at the moment but a simple google search will get you a preview of the mod.
Heres where I soldered the VR wire to:
Using a 680 Classified I managed to get it running without a PCI-Power.
Now that we have a proof of concept and basic knowledge we can get into how to make a W-Power* board
On the 680 Classified the voltages are labeled in the picture:
5V output is located on the bottom of the LDO where the 12V goes.
Make a 3.3V circuit and short the ground sense pins:
Check voltages on all rails using the handy ProbeIt connector.(the picture a few images above should serve enough justice)
Cutting of the card is a difficult decision but I decided to remove the 330 Ohm capacitors(the black ones) and cut inbetween where they were. The reason behind removing them is to have a nice large surface to attach to the recipient card.
Time to test.
More updates will come as I do further testing on more cards. As I stated in the beginning I am not an engineer or professionally trained in electronics. I simply read many articles on the topic and was able to infer proper construction of this product. Its very easy to just buy a dead or cheap Classified card with working VRM, solder a few components and cut in the right place. I highly suggest reading the forum posts and datasheets for more info if you would like to do this with any other type of card(lightning or what have you).
Good luck and thanks for reading this guide. Any input or corrections are welcome.
1. Conversion your dead 2900XT into useful beast
2.Need zombie? Make yourself, some help arrive here
3. Image: PCI-E 3.0 Pinout
4. Chil CHL8318 Datasheet
5. TiN's 3.3V circuit guide